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756 results on '"Soszyński, I."'

2. The EURONEAR Lightcurve Survey of Near Earth Asteroids 2017–2020

Author

Vaduvescu, O., Aznar Macias, A., Wilson, T. G., Zegmott, T., Pérez Toledo, F. M., Predatu, M., Gherase, R., Pinter, V., Pozo Nunez, F., Ulaczyk, K., Soszyński, I., Mróz, P., Wrona, M., Iwanek, P., Szymanski, M., Udalski, A., Char, F., Salas Olave, H., Aravena-Rojas, G., Vergara, A. C., Saez, C., Unda-Sanzana, E., Alcalde, B., de Burgos, A., Nespral, D., Galera-Rosillo, R., Amos, N. J., Hibbert, J., López-Comazzi, A., Oey, J., Serra-Ricart, M., Licandro, J., and Popescu, M.

Published
2022
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3. No massive black holes in the Milky Way halo.

Author

Mróz P, Udalski A, Szymański MK, Soszyński I, Wyrzykowski Ł, Pietrukowicz P, Kozłowski S, Poleski R, Skowron J, Skowron D, Ulaczyk K, Gromadzki M, Rybicki K, Iwanek P, Wrona M, and Ratajczak M

Abstract

The gravitational wave detectors have shown a population of massive black holes that do not resemble those observed in the Milky Way 1-3 and whose origin is debated 4-6 . According to a possible explanation, these black holes may have formed from density fluctuations in the early Universe (primordial black holes) 7-9 , and they should comprise several to 100% of dark matter to explain the observed black hole merger rates 10-12 . If these black holes existed in the Milky Way dark matter halo, they would cause long-timescale gravitational microlensing events lasting years 13 . The previous experiments were not sufficiently sensitive to such events 14-17 . Here we present the results of the search for long-timescale microlensing events among the light curves of nearly 80 million stars located in the Large Magellanic Cloud that were monitored for 20 years by the Optical Gravitational Lensing Experiment survey 18 . We did not find any events with timescales longer than 1 year, whereas all shorter events detected may be explained by known stellar populations. We find that compact objects in the mass range from 1.8 × 10 -4 M ⊙ to 6.3M ⊙ cannot make up more than 1% of dark matter, and those in the mass range from 1.3 × 10 -5 M ⊙ to 860 M ⊙ cannot make up more than 10% of dark matter. Thus, primordial black holes in this mass range cannot simultaneously explain a substantial fraction of dark matter and gravitational wave events., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Published
2024
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5. Campaign 9 of the K2 Mission : Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey

Author

Henderson, Calen B., Poleski, Radosław, Penny, Matthew, Street, Rachel A., Bennett, David P., Hogg, David W., Gaudi, B. Scott, Zhu, W., Barclay, T., Barentsen, G., Howell, S. B., Mullally, F., Udalski, A., Szymański, M. K., Skowron, J., Mróz, P., Kozłowski, S., Wyrzykowski, Ł., Pietrukowicz, P., Soszyński, I., Ulaczyk, K., Pawlak, M., Sumi, T., Abe, F., Asakura, Y., Barry, R. K., Bhattacharya, A., Bond, I. A., Donachie, M., Freeman, M., Fukui, A., Hirao, Y., Itow, Y., Koshimoto, N., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Nagakane, M., Ohnishi, K., Oyokawa, H., Rattenbury, N., Saito, To., Sharan, A., Sullivan, D. J., Tristram, P. J., Yonehara, A., Bachelet, E., Bramich, D. M., Cassan, A., Dominik, M., Jaimes, R. Figuera, Horne, K., Hundertmark, M., Mao, S., Ranc, C., Schmidt, R., Snodgrass, C., Steele, I. A., Tsapras, Y., Wambsganss, J., Bozza, V., Burgdorf, M. J., Jørgensen, U. G., Novati, S. Calchi, Ciceri, S., D’Ago, G., Evans, D. F., Hessman, F. V., Hinse, T. C., Husser, T.-O., Mancini, L., Popovas, A., Rabus, M., Rahvar, S., Scarpetta, G., Skottfelt, J., Southworth, J., Unda-Sanzana, E., Bryson, S. T., Caldwell, D. A., Haas, M. R., Larson, K., McCalmont, K., Packard, M., Peterson, C., Putnam, D., Reedy, L., Ross, S., Van Cleve, J. E., Akeson, R., Batista, V., Beaulieu, J.-P., Beichman, C. A., Bryden, G., Ciardi, D., Cole, A., Coutures, C., Foreman-Mackey, D., Fouqué, P., Friedmann, M., Gelino, C., Kaspi, S., Kerins, E., Korhonen, H., Lang, D., Lee, C.-H., Lineweaver, C. H., Maoz, D., Marquette, J.-B., Mogavero, F., Morales, J. C., Nataf, D., Pogge, R. W., Santerne, A., Shvartzvald, Y., Suzuki, D., Tamura, M., Tisserand, P., and Wang, D.

Published
2016

6. Binary central stars of planetary nebulae in the Large Magellanic Cloud.

Author

Gładkowski, M., Hajduk, M., Smolec, R., Szczerba, R., and Soszyński, I.

Subjects
LARGE magellanic cloud, PLANETARY nebulae, BINARY stars, SMALL magellanic cloud, GALACTIC bulges
Abstract

Context. Close binary central stars of planetary nebulae (PNe) must have formed through a common envelope evolution during the giant phase experienced by one of the stars. Transfer of the angular momentum from the binary system to the envelope leads to the shortening of the binary separations from the radius of red giant to the radius of the order of few tenths of AU. Thus, close binary central stars of planetary nebulae are laboratories to study the common envelope phase of evolution. The close binary fraction in the Galaxy has been measured in various sky surveys, but the close binary fraction is not yet well constrained for the Magellanic Clouds, and our results may help the study of common envelope evolution in low-metallicity environments. Aims. This paper presents a continuation of our study of variability in the Magellanic Cloud planetary nebulae on the basis of data from the OGLE survey. Previously, we had analysed the OGLE data in the Small Magellanic Cloud. Here, the study is extended to the Large Magellanic Cloud (LMC). In this paper we search for close binary central stars with the aim to constrain the binary fraction and period distribution in the LMC. Methods. We identified 290 counterparts of PNe in the LMC in the I-band images from the OGLE-III and OGLE-IV surveys. However, the light curves of ten objects were not accessible in the OGLE database, and thus we analysed the time series photometry of 280 PNe. Results. In total, 32 variables were found, but 5 of them turned out to be foreground objects. Another 18 objects show irregular or regular variability that is not attributable to the binarity of their central stars. Their status and the nature of their variability will be verified in the follow-up paper. Nine binary central stars of PNe with periods between 0.24 and 23.6 days were discovered. The obtained fraction for the LMC PNe is 3.3-1.6+2.6% without correcting for incompleteness. This number is significantly lower than the 12–21% derived in the analogous search in the Galactic bulge. We discuss this difference, taking into account observational biases. The lower binary fraction suggests a lower efficiency of the common envelope phase in producing close binaries in the LMC compared to the Galaxy. [ABSTRACT FROM AUTHOR]

Published
2024
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7. The B-type Binaries Characterisation Programme – II. VFTS 291: a stripped star from a recent mass transfer phase.

Author

Villaseñor, J I, Lennon, D J, Picco, A, Shenar, T, Marchant, P, Langer, N, Dufton, P L, Nardini, F, Evans, C J, Bodensteiner, J, de Mink, S E, Götberg, Y, Soszyński, I, Taylor, W D, and Sana, H

Subjects
MASS transfer, LOW mass stars, BINARY stars, STELLAR evolution, STAR clusters
Abstract

Recent studies of massive binaries with putative black hole companions have uncovered a phase of binary evolution that has not been observed before, featuring a bloated stripped star that very recently ceased transferring mass to a main-sequence companion. In this study, we focus on the candidate system VFTS 291, a binary with an orbital period of 108 d and a high semi-amplitude velocity (K 1 = 93.7 ± 0.2 km s−1). Through our analysis of the disentangled spectra of the two components, together with dynamical and evolutionary arguments, we identify a narrow-lined star of ∼1.5–2.5 |$\, \mathrm{M}_\odot$| dominating the spectrum, and an early B-type main-sequence companion of 13.2 ± 1.5 |$\, \mathrm{M}_\odot$|⁠. The low mass of the narrow-lined star, and the high mass ratio, suggest that VFTS 291 is a post-mass-transfer system, with the narrow-lined star being bloated and stripped of its hydrogen-rich envelope, sharing many similarities with other recently discovered stripped stars. Our finding is supported by our detailed binary evolution models, which indicate that the system can be well explained by an initial configuration consisting of an 8.1 |$\, \mathrm{M}_\odot$| primary with an 8 |$\, \mathrm{M}_\odot$| companion in a 7 d orbital period. While some open questions remain, particularly concerning the surface helium enrichment of the stripped star and the rotational velocity of the companion, we expect that high-resolution spectroscopy may help reconcile our estimates with theory. Our study highlights the importance of multi-epoch spectroscopic surveys to identify and characterize binary interaction products, and provides important insights into the evolution of massive binary stars. [ABSTRACT FROM AUTHOR]

Published
2023
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8. The OGLE Collection of Variable Stars. Over 2600 Delta Scuti Stars in the Small Magellanic Cloud

Author

Soszyński, I., Udalski, A., Skowron, J., Pietrukowicz, P., Szymański, M. K., Poleski, R., Skowron, D. M., Kozłowski, S., Mróz, P., Iwanek, P., Wrona, M., Ulaczyk, K., Rybicki, K., and Gromadzki, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astrophysics - Astrophysics of Galaxies, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We present the first-ever collection of delta Scuti stars found over the entire area of the Small Magellanic Cloud (SMC). The sample consists of 2810 variables of which over 2600 objects belong to the SMC while the remaining stars are most likely members of the Milky Way's halo. The sample has been divided into 2733 singlemode and 77 multimode pulsators. We provide observational parameters (pulsation periods, mean magnitudes, amplitudes, Fourier coefficients) of all delta Sct stars and the long-term I- and V-band time-series photometric measurements collected during the fourth phase of the Optical Gravitational Lensing Experiment (OGLE-IV)., 12 pages, 5 figures, submitted to Acta Astronomica

Published
2023

9. Hydrogen-rich supernovae beyond the neutrino-driven core-collapse paradigm

Author

Terreran, G., Pumo, M. L., Chen, T.-W., Moriya, T. J., Taddia, F., Dessart, L., Zampieri, L., Smartt, S. J., Benetti, S., Inserra, C., Cappellaro, E., Nicholl, M., Fraser, M., Wyrzykowski, Ł., Udalski, A., Howell, D. A., McCully, C., Valenti, S., Dimitriadis, G., Maguire, K., Sullivan, M., Smith, K. W., Yaron, O., Young, D. R., Anderson, J. P., Della Valle, M., Elias-Rosa, N., Gal-Yam, A., Jerkstrand, A., Kankare, E., Pastorello, A., Sollerman, J., Turatto, M., Kostrzewa-Rutkowska, Z., Kozłowski, S., Mróz, P., Pawlak, M., Pietrukowicz, P., Poleski, R., Skowron, D., Skowron, J., Soszyński, I., Szymański, M. K., and Ulaczyk, K.

Published
2017
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10. A terrestrial planet in a ∼1-AU orbit around one member of a ∼15-AU binary

Author

Gould, A., Udalski, A., Shin, I.-G., Porritt, I., Skowron, J., Han, C., Yee, J. C., Kozłowski, S., Choi, J.-Y., Poleski, R., Wyrzykowski, Ł., Ulaczyk, K., Pietrukowicz, P., Mróz, P., Szymański, M. K., Kubiak, M., Soszyński, I., Pietrzyński, G., Gaudi, B. S., Christie, G. W., Drummond, J., McCormick, J., Natusch, T., Ngan, H., Tan, T.-G., Albrow, M., DePoy, D. L., Hwang, K.-H., Jung, Y. K., Lee, C.-U., Park, H., Pogge, R. W., Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Fukunaga, D., Itow, Y., Koshimoto, N., Larsen, P., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Namba, S., Ohnishi, K., Philpott, L., Rattenbury, N. J., Saito, To., Sullivan, D. J., Sumi, T., Suzuki, D., Tristram, P. J., Tsurumi, N., Wada, K., Yamai, N., Yock, P. C. M., Yonehara, A., Shvartzvald, Y., Maoz, D., Kaspi, S., and Friedmann, M.

Published
2014

11. An Isolated Microlens Observed from K2, Spitzer, and Earth

Author

Zhu, Wei, Udalski, A, Huang, C. X, Novati, S. Calchi, Sumi, T, Poleski, R, Skowron, J, Mróz, P, Szymański, M. K, Soszyński, I, Pietrukowicz, P, Kozłowski, S, Ulaczyk, K, Pawlak, M, Beichman, C, Bryden, G, Carey, S, Gaudi, B. S, Gould, A, Henderson, C. B, Shvartzvald, Y, Yee, J. C, Bond, I. A, Bennett, D. P, Suzuki, D, Rattenbury, N. J, Koshimoto, N, Abe, F, Asakura, Y, Barry, R. K, Bhattacharya, A, Donachie, M, Evans, P, Fukui, A, Hirao, Y, Itow, Y, Kawasaki, K, Li, M. C. A, Ling, C. H, Masuda, K, Matsubara, Y, Miyazaki, S, Munakata, H, Muraki, Y, Nagakane, M, Ohnishi, K, Ranc, C, Saito, To, Sharan, A, Sullivan, D. J, Tristram, P. J, Yamada, Y, and Yonehara, A

Subjects
Astrophysics
Abstract

We present the result of microlensing event MOA-2016-BLG-290, which received observations from the two-wheel Kepler (K2), Spitzer, as well as ground-based observatories. A joint analysis of data from K2 and the ground leads to two degenerate solutions of the lens mass and distance. This degeneracy is effectively broken once the (partial) Spitzer light curve is included. Altogether, the lens is found to be an extremely low-mass star or brown dwarf (77(sup +34)(sub -23) M(sub J)) located in the Galactic bulge (6.8 ± 0.4 kpc). MOA-2016-BLG-290 is the first microlensing event for which we have signals from three well-separated (~1 au) locations. It demonstrates the power of two-satellite microlensing experiment in reducing the ambiguity of lens properties, as pointed out independently by S. Refsdal and A. Gould several decades ago.

Published
2017
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12. OGLE-2016-BLG-1469L: Microlensing Binary Composed of Brown Dwarfs

Author

Han, C, Udalski, A, Sumi, T, Gould, A, Albrow, M. D, Chung, S.-J, Jung, Y. K, Ryu, Y.-H, Shin, I.-G, Yee, J. C, Zhu, W, Cha, S.-M, Kim, S.-L, Kim, D.-J, Lee, C.-U, Lee, Y, Park, B.-G, Soszyński, I, Mróz, P, Pietrukowicz, P, Szymański, M. K, Skowron, J, Poleski, R, Kozłowski, S, Ulaczyk, K, Pawlak, M, Abe, F, Asakura, Y, Bennett, D. P, Bond, I. A, Bhattacharya, A, Donachie, M, Freeman, M, Fukui, A, Hirao, Y, Itow, Y, Koshimoto, N, Li, M. C. A, Ling, C. H, Masuda, K, Matsubara, Y, Muraki, Y, Nagakane, M, Ohnishi, K, Oyokawa, H, Rattenbury, N. J, Saito, To, Sharan, A, Sullivan, D. J, Suzuki, D, Tristram, P. J, Yamada, T, Yonehara, A, and Barry, R

Subjects
Astrophysics
Abstract

We report the discovery of a binary composed of two brown dwarfs, based on the analysis of the micro lensing event OGLE-2016-BLG-1469. Thanks to the detection of both finite-source and micro lens-parallax effects, we are able to measure both the masses M(sub 1) ~ 0.05 Solar Mass and M(sub 2) ~ 0.01 Solar Mass, and the distance D(sub L) ~ 4.5 kpc, as well as the projected separation a(sub perpendicular) ~ 0.33 au. This is the third brown-dwarf binary detected using the micro lensing method, demonstrating the usefulness of micro lensing in detecting field brown-dwarf binaries with separations of less than 1 au.

Published
2017
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13. OGLE-2013-BLG-1761Lb: A Massive Planet around an MK Dwarf

Author

Hirao, Y, Udalski, A, Sumi, T, Bennett, D. P, Koshimoto, N, Bond, I. A, Rattenbury, N. J, Suzuki, D, Abe, F, Asakura, Y, Barry, R. K, Bhattacharya, A, Donachie, M, Evans, P, Fukui, A, Itow, Y, Li, M. C. A, Ling, C. H, Masuda, K, Matsubara, Y, Matsuo, T, Muraki, Y, Nagakane, M, Ohnishi, K, Ranc, C, Saito, To, Sharan, A, Shibai, H, Sullivan, D. J, Tristram, P. J, Yamada, T, Yonehara, A, Poleski, R, Skowron, J, Mróz, P, Szymański, M. K, Kozłowski, S, Pietrukowicz, P, Soszyński, I, Wyrzykowski, L, and Ulaczyk, K

Subjects
Astrophysics
Abstract

We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. However, the detailed light curve analysis ruled out all stellar binary models and shows the lens to be a planetary system. There is the so-called close wide degeneracy in the solutions with the planet host mass ratio of q approx.(7.0+/-2.0) x 10(exp -3) and q approx.(8.1+/-2.6) x 10(exp -3) with the projected separation in Einstein radius units of s = 0.95 (close) and s = 1.18(wide), respectively. The microlens parallax effect is not detected, but the finite source effect is detected. Our Bayesian analysis indicates that the lens system is located -D(sub L) = 6.9(+ 1.0 -1.2)kpc away from us and the host star is an M/K dwarf with amass of M(sub L) = 0.33(+ 0.32- 1.9)Stellar Mass orbited by a super-Jupiter mass planet with a mass of m(sub p) = 2.7(+ 2.5 - 1.5) M(sub Jup) at the projected separation of a(sub l) = 1.8(+ 0.5 -0.5)au. The preference of the large lens distance in the Bayesian analysis is due to the relatively large observed source star radius. The distance and other physical parameters may be constrained by the future high-resolution imaging by large ground telescopes or HST. If the estimated lens distance is correct, then this planet provides another sample for testing the claimed deficit of planets in the Galactic bulge.

Published
2017
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14. OGLE-2019-BLG-0033/MOA-2019-BLG-035

Author

Herald, A., Udalski, A., Bozza, V., Rota, P., Bond, I. A., Yee, J. C., Sajadian, S., Mróz, P., Poleski, R., Skowron, J., Szymański, M. K., Soszyński, I., Pietrukowicz, P., Kozłowski, S., Ulaczyk, K., Rybicki, K. A., Iwanek, P., Wrona, M., Gromadzki, M., Abe, F., Barry, R., Bennett, D. P., Bhattacharya, A., Fukui, A., Fujii, H., Hirao, Y., Itow, Y., Kirikawa, R., Kondo, I., Koshimoto, N., Matsubara, Y., Matsumoto, S., Miyazaki, S., Muraki, Y., Olmschenk, G., Ranc, C., Okamura, A., Rattenbury, N. J., Satoh, Y., Sumi, T., Suzuki, D., Silva, S. Ishitani, Toda, T., Tristram, P. J., Vandorou, A., Yama, H., Beichman, C. A., Bryden, G., Novati, S. Calchi, Carey, S., Gaudi, B. S., Gould, A., Henderson, C. B., Johnson, S., Shvartzvald, Y., Zhu, W., Dominik, M., Hundertmark, M., Jørgensen, U. G., Longa-Peña, P., Skottfelt, J., Tregloan-Reed, J., Bach-Møller, N., Burgdorf, M., D’Ago, G., Haikala, L., Hitchcock, J., Khalouei, E., Peixinho, N., Rahvar, S., Snodgrass, C., Southworth, J., Spyratos, P., Zang, W., Yang, H., Mao, S., Bachelet, E., Maoz, D., Street, R. A., Tsapras, Y., Christie, G. W., Cooper, T., de Almeida, L., do Nascimento, J.-D., Green, J., Han, C., Hennerley, S., Marmont, A., McCormick, J., Monard, L. A. G., Natusch, T., and Pogge, R.

Subjects
binaries: general, stars: low-mass, gravitational lensing: micro, brown dwarfs
Abstract

Context Brown dwarfs are transition objects between stars and planets that are still poorly understood, for which several competing mechanisms have been proposed to describe their formation. Mass measurements are generally difficult to carry out for isolated objects as well as for brown dwarfs orbiting low-mass stars, which are often too faint for a spectroscopic follow-up. \ud \ud Aims Microlensing provides an alternative tool for the discovery and investigation of such faint systems. Here, we present an analysis of the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035, which is caused by a binary system composed of a brown dwarf orbiting a red dwarf. \ud \ud Methods Thanks to extensive ground observations and the availability of space observations from Spitzer, it has been possible to obtain accurate estimates of all microlensing parameters, including the parallax, source radius, and orbital motion of the binary lens. \ud \ud Results Following an accurate modeling process, we found that the lens is composed of a red dwarf with a mass of M1 = 0.149 ± 0.010 M⊙ and a brown dwarf with a mass of M2 = 0.0463 ± 0.0031 M⊙at a projected separation of a⊥ = 0.585 au. The system has a peculiar velocity that is typical of old metal-poor populations in the thick disk. A percent-level precision in the mass measurement of brown dwarfs has been achieved only in a few microlensing events up to now, but will likely become more common in the future thanks to the Roman space telescope.

Published
2022

18. Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way

Author

Howes, L. M., Casey, A. R., Asplund, M., Keller, S. C., Yong, D., Nataf, D. M., Poleski, R., Lind, K., Kobayashi, C., Owen, C. I., Ness, M., Bessell, M. S., Da Costa, G. S., Schmidt, B. P., Tisserand, P., Udalski, A., Szymański, M. K., Soszyński, I., Pietrzyński, G., Ulaczyk, K., Wyrzykowski, Ł., Pietrukowicz, P., Skowron, J., Kozłowski, S., and Mróz, P.

Published
2015
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19. Single lens mass measurement in the high magnification microlensing event Gaia19bld located in the Galactic Disk

Author

Rybicki, K.A., Wyrzykowski, Ł., Bachelet, E., Cassan, A., Zieliński, P., Gould, A., Calchi Novati, S., Yee, J.C., Ryu, Y.-H., Gromadzki, M., Mikołayczyk, P., Ihanec, N., Kruszyńska, K., Hambsch, F.-J., Zola, S., Fossey, S.J., Awiphan, S., Nakharutai, N., Lewis, F., Olivares E., F., Hodgkin, S., Delgado, A., Breedt, E., Harrison, D.L., van Leeuwen, M., Rixon, G., Wevers, T., Yoldas, A., Udalski, A., Szymański, M.K., Soszyński, I., Pietrokowicz, P., Kozłowski, S., Skowron, J., Poleski, R., Ulaczyk, K., Mróz, P., Iwanek, P., Wrona, M., Street, R.A., Tsapras, Y., Hundertmark, M., Dominik, Martin, Beichman, C., Bryden, G., Carey, S., Gaudi, B.S., Henderson, C., Shvartzwald, Y., Zang, W., Zhu, W., Christie, G.W., Green, J., Hennerley, S., McCormick, J., Monard, L.A.G., Natusch, T., Pogge, R.W., Gezer, I., Gurgul, A., Kaczmarek, Z., Lam, M.C., Maskoliunas, M., Pakstiene, E., Stankeviciute, A., Zdanavicius, J., Ziółkowska, O., European Commission, University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science

Subjects
QC Physics, Stellar remnants, Microlensing, NDAS, QB Astronomy, QC, QB
Abstract

Funding: This work was supported from the Polish NCN grants: Preludium No. 2017/25/N/ST9/01253, Harmonia No. 2018/30/M/ST9/00311, MNiSW grant DIR/WK/2018/12, Daina No. 2017/27/L/ST9/03221, and by the Research Council of Lithuania, grant No. S-LL-19-2. . The OGLE project has received funding from the NCN grant MAESTRO 2014/14/A/ST9/00121 to AU. We acknowledge the European Commission’s H2020 OPTICON grant No. 730890. YT acknowledges the support of DFG priority program SPP 1992 "Exploring the Diversity of Extrasolar Planets" (WA 1047/11-1). EB and RS gratefully acknowledge support from NASA grant 80NSSC19K0291. Work by AG was supported by JPL grant 1500811. Work by JCY was supported by JPL grant 1571564. SJF thanks Telescope Live for access to their telescope network. NN acknowledges the support of Data Science Research Center, Chiang Mai University. F.O.E. acknowledges support from the FONDECYT grant nr. 1201223. Context. Microlensing gives a unique opportunity to detect non-luminous objects. In the rare cases that the Einstein radius θ_E and microlensing parallax π_E can be measured, it is possible to determine the mass of the lens. With technological advances in both ground and space-based observatories, astrometric and interferometric measurements are becoming viable, which can lead to the more routine determination of θE and, if the microlensing parallax is also measured, the mass of the lens. Aims. We present the photometric analysis of Gaia19bld, a high magnification (A ≈ 60) microlensing event located in the southern Galactic plane, which exhibited finite source and microlensing parallax effects. Due to a prompt detection by the Gaia satellite and the very high brightness of I = 9.05 mag at the peak, it was possible to collect a complete and unique set of multi-channel follow-up observations, which allowed us to determine all parameters vital for the characterisation of the lens and the source in the microlensing event. Methods. Gaia19bld was discovered by the Gaia satellite and was subsequently densely followed-up with a network of ground based observatories and the Spitzer Space Telescope. We collected multiple high resolution spectra with VLT/X-Shooter to characterise the source star. The event was also observed with VLTI/PIONIER during the peak. Here we focus on the photometric observations and model the light curve composed of data from Gaia, Spitzer and multiple optical, ground-based observatories. We find the best fitting solution with parallax and finite source effects. We derive the limit on the luminosity of the lens based on the blended light model and spectroscopic distance. Results. We compute the mass of the lens to be 1.13 ± 0.03 M⊙ and derive its distance to be 5.52−0.64+0.35 kpc. The lens is likely a main sequence star, however its true nature has yet to be verified by the future high resolution observations. Our results are consistent with interferometric measurements of the angular Einstein radius, emphasising that interferometry can be a new channel for determining the masses of objects that would otherwise remain undetectable, including stellar-mass black holes. Postprint

Published
2021

21. Publisher Correction: Hydrogen-rich supernovae beyond the neutrino-driven core-collapse paradigm

Author

Terreran, G., Pumo, M. L., Chen, T.-W., Moriya, T. J., Taddia, F., Dessart, L., Zampieri, L., Smartt, S. J., Benetti, S., Inserra, C., Cappellaro, E., Nicholl, M., Fraser, M., Wyrzykowski, Ł., Udalski, A., Howell, D. A., McCully, C., Valenti, S., Dimitriadis, G., Maguire, K., Sullivan, M., Smith, K. W., Yaron, O., Young, D. R., Anderson, J. P., Della Valle, M., Elias-Rosa, N., Gal-Yam, A., Jerkstrand, A., Kankare, E., Pastorello, A., Sollerman, J., Turatto, M., Kostrzewa-Rutkowska, Z., Kozłowski, S., Mróz, P., Pawlak, M., Pietrukowicz, P., Poleski, R., Skowron, D., Skowron, J., Soszyński, I., Szymański, M. K., and Ulaczyk, K.

Published
2018
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22. EXOPLANET DETECTION: A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary

Author

Gould, A., Udalski, A., Shin, I.-G., Porritt, I., Skowron, J., Han, C., Yee, J. C., Kozłowski, S., Choi, J.-Y., Poleski, R., Wyrzykowski, Ł., Ulaczyk, K., Pietrukowicz, P., Mróz, P., Szymański, M. K., Kubiak, M., Soszyński, I., Pietrzynski, G., Gaudi, B. S., Christie, G. W., Drummond, J., McCormick, J., Natusch, T., Ngan, H., Tan, T.-G., Albrow, M., DePoy, D. L., Hwang, K.-H., Jung, Y. K., Lee, C.-U., Park, H., Pogge, R. W., Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Fukunaga, D., Itow, Y., Koshimoto, N., Larsen, P., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Namba, S., Ohnishi, K., Philpott, L., Rattenbury, N. J., Saito, To., Sullivan, D. J., Sumi, T., Suzuki, D., Tristram, P. J., Tsurumi, N., Wada, K., Yamai, N., Yock, P. C. M., Yonehara, A., Shvartzvald, Y., Maoz, D., Kaspi, S., and Friedmann, M.

Published
2014
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23. Over 10 000 δ Scuti Stars toward the Galactic Bulge from OGLE-IV

Author

Pietrukowicz, P., Soszyński, I., Netzel, H., Wrona, M., Udalski, A., Szymanski, M. K., Poleski, R., Kozłowski, S., Skowron, J., Ulaczyk, K., Skowron, D. M., Mróz, P., Rybicki, K., Iwanek, P., and Gromadzki, M.

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present a collection of 10 111 genuine δ Sct-type pulsating variable stars detected in the OGLE-IV Galactic bulge fields. In this sample, 9835 variables are new discoveries. For most of the stars photometric data cover the whole decade 2010-2019. We illustrate a huge variety of light curve shapes of δ Sct variables. Long-term observations have allowed us to spot objects with evident period, amplitude, and mean brightness variations. Our analysis indicates that about 28% of the stars are single-mode pulsators. Fourteen δ Sct stars show additional eclipsing or ellipsoidal binary modulation. We report significant attenuation or even disappearance of the pulsation signal in six sources. The whole set of variables is a mix of objects representing various Milky Way's populations, with the majority of stars from the Galactic bulge. There are also representatives of the Sagittarius Dwarf Spheroidal Galaxy. Some of the newly detected variables could be SX Phe-type stars residing in globular clusters. The collection, including full V- and I-band time-series data, is available to the astronomical community from the OGLE On-line Data Archive.

Published
2020

24. A Super-Jupiter Orbiting A Late-Type Star: A Refined Analysis of Microlensing Event OGLE-2012-BLG-0406

Author

Tsapras, Y, Choi, J.-Y, Street, R. A, Han, C, Bozza, V, Gould, A, Dominik, M, Beaulieu, J.-P, Udalski, A, Jørgensen, U. G, Sumi, T, Bramich, D. M, Browne, P, Horne, K, Hundertmark, M, Kains, N, Snodgrass, C, Steele, I. A, Andersen, J. M, Novati, S. Calchi, Diehl, C, Giannini, E, Hardis, S, Harpsøe, K, Hinse, T. C, Juncher, D, Kerins, E, Korhonen, H, Liebig, C, Mancini, L, Mathiasen, M, Penny, M. T, Rabus, M, Rahvar, S, Scarpetta, G, Skottfelt, J, Southworth, J, Tregloan-Reed, J, Vilela, C, Wambsganss, J, Skowron, J, Poleski, R, Kozłowski, S, Wyrzykowski, Ł, Szymański, M. K, Kubiak, M, Pietrukowicz, P, Pietrzyński, G, Soszyński, I, Ulaczyk, K, Albrow, M. D, Bachelet, E, Barry, R, Batista, V, Bhattacharya, A, Brillant, S, Caldwell, J. A. R, Cassan, A, Cole, A, Corrales, E, Coutures, Ch, Dieters, S, Prester, D. Dominis, Donatowicz, J, Fouqu, P, Greenhill, J, Kane, S. R, Kubas, D, Marquette, J. B, Menzies, J, Père, C, Pollard, K. R, Zub, M, Christie, G, DePoy, D. L, Dong, S, Gaudi, B. S, Henderson, C. B, Hwang, K. H, Jung, Y. K, Kavka, A, Koo, J.-R, Lee, C.-U, Maoz, D, Natusch, T, Ngan, H, Park, H, Pogge, R. W, Shin, I. G, Shvartzvald, Y, Yee, J. C, Abe, F, Bennett, D. P, Bond, I. A, Botzler, C. S, Freeman, M, Fukui, A, Fukunaga, D, Itow, Y, Koshimoto, N, Ling, C. H, Masuda, K, Matsubara, Y, Muraki, Y, Namba, S, Ohnishi, K, Rattenbury, N. J, Saito, To, Sullivan, D. J, Sweatman, W. L, Suzuki, D, Tristram, P. J, Tsurumi, N, Wada, K, Yamai, N, Yock, P. C. M, and Yonehara, A

Subjects
Astronomy, Astrophysics
Abstract

We present a detailed analysis of survey and follow-up observations of microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different observatories. Intensive coverage of the light curve, especially the perturbation part, allowed us to accurately measure the parallax effect and lens orbital motion. Combining our measurement of the lens parallax with the angular Einstein radius determined from finite-source effects, we estimate the physical parameters of the lens system. We find that the event was caused by a 2.73 plus or minus 0.43 M (sub J) planet orbiting a 0.44 plus or minus 0.07 solar mass early M-type star. The distance to the lens is 4.97 plus or minus 0.29 kpc and the projected separation between the host star and its planet at the time of the event is 3.45 plus or minus 0.26 AU. We find that the additional coverage provided by follow-up observations, especially during the planetary perturbation, leads to a more accurate determination of the physical parameters of the lens.

Published
2014
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26. Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing

Author

Beaulieu, J.-P., Bennett, D. P., Fouque, P., Williams, A., Dominik, M., Jorgensen, U. G., Kubas, D., Cassan, A., Coutures, C., Greenhill, J., Hill, K., Menzies, J., Sackett, P. D., Albrow, M., Brillant, S., Caldwell, J. A. R., Calitz, J. J., Cook, K. H., Corrales, E., Desort, M., Dieters, S., Dominis, D., Donatowicz, J., Hoffman, M., Kane, S., Marquette, J.-B., Martin, R., Meintjes, P., Pollard, K., Sahu, K., Vinter, C., Wambsganss, J., Woller, K., Horne, K., Steele, I., Bramich, D. M., Burgdorf, M., Snodgrass, C., Bode, M., Udalski, A., Szymański, M. K., Kubiak, M., Wi[??]ckowski, T., Pietrzyński, G., Soszyński, I., Szewczyk, O., Wyrzykowski, Ł., Paczyński, B., Abe, F., Bond, I. A., Britton, T. R., Gilmore, A. C., Hearnshaw, J. B., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A. V., Masuda, K., Matsubara, Y., Motomura, M., Muraki, Y., Nakamura, S., Okada, C., Ohnishi, K., Rattenbury, N. J., Sako, T., Sato, S., Sasaki, M., Sekiguchi, T., Sullivan, D. J., Tristram, P. J., Yock, P. C. M., and Yoshioka, T.

Subjects
Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): J.-P. Beaulieu (corresponding author) [1, 4]; D. P. Bennett [1, 3, 5]; P. Fouqué [1, 6]; A. Williams [1, 7]; M. Dominik [1, 8]; U. G. Jørgensen [1, 9]; [...]

Published
2006
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27. An eclipsing-binary distance to the Large Magellanic Cloud accurate to two per cent

Author

Pietrzyński, G., Graczyk, D., Gieren, W., Thompson, I. B., Pilecki, B., Udalski, A., Soszyński, I., Kozłowski, S., Konorski, P., Suchomska, K., Bono, G., Moroni, Prada P. G., Villanova, S., Nardetto, N., Bresolin, F., Kudritzki, R. P., Storm, J., Gallenne, A., Smolec, R., Minniti, D., Kubiak, M., Szymański, M. K., Poleski, R., Wyrzykowski, Ł., Ulaczyk, K., Pietrukowicz, P., Górski, M., and Karczmarek, P.

Published
2013
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28. Frequency analysis of δ Scuti stars towards the Galactic bulge.

Author

Netzel, H, Pietrukowicz, P, Soszyński, I, and Wrona, M

Subjects
PULSATING stars, GRAVITATIONAL lenses, STELLAR oscillations, VARIABLE stars, CEPHEIDS, GALACTIC bulges
Abstract

We have performed a frequency analysis of 10 092 δ Scuti-type stars detected in the fourth phase of the Optical Gravitational Lensing Experiment towards the Galactic bulge, which is the most numerous homogeneous sample of δ Scuti stars observed so far. The main goal was to search for stars pulsating in at least two radial modes simultaneously. We have found 3083 candidates for such stars, which is the largest set obtained to date. Among them, 2655 stars pulsate in two radial modes, 414 stars pulsate in three radial modes, and 14 stars pulsate in four radial modes at the same time. We report the identification of 221 δ Scuti stars pulsating in the fundamental mode, first overtone, and third overtone simultaneously. We show the most populated Petersen and Bailey diagrams and discuss statistical properties of the identified frequencies based on this numerous sample. Additionally, we present theoretical predictions of period ratios for δ Scuti stars pulsating in overtones from the fourth to the seventh. [ABSTRACT FROM AUTHOR]

Published
2022
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30. Unbound or distant planetary mass population detected by gravitational microlensing

Author

Sumi, T., Kamiya, K., Bennett, D. P., Bond, I. A., Abe, F., Botzler, C. S., Fukui, A., Furusawa, K., Hearnshaw, J. B., Itow, Y., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Motomura, M., Muraki, Y., Nagaya, M., Nakamura, S., Ohnishi, K., Okumura, T., Perrott, Y. C., Rattenbury, N., Saito, To., Sako, T., Sullivan, D. J., Sweatman, W. L., Tristram, P. J., Yock, P. C. M., Udalski, A., Szymański, M. K., Kubiak, M., Pietrzyński, G., Poleski, R., Soszyński, I., Wyrzykowski, Ł., and Ulaczyk, K.

Published
2011
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32. A Wide-orbit Exoplanet OGLE-2012-BLG-0838Lb.

Author

Poleski, R., Suzuki, Daisuke, Udalski, A., Xie, Xiaojia, Yee, J. C., Koshimoto, Naoki, Gaudi, B. S., Gould, A., authors, leading, Skowron, J., Szymański, M. K., Soszyński, I., Pietrukowicz, P., Kozłowski, S., Wyrzykowski, Ł., Ulaczyk, K., tion, Abe, Fumio, Barry, Richard K., and Bennett, David. P.

Published
2020
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33. Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing

Author

Gaudi, B S., Bennett, D. P., Udalski, A., Gould, A., Christie, G. W., Maoz, D., Dong, S., McCormick, J., Szymański, M. K., Tristram, P. J., Nikolaev, S., Paczyński, B., Kubiak, M., Pietrzyński, G., Soszyński, I., Szewczyk, O., Ulaczyk, K., Wyrzykowski, Ł., DePoy, D. L., Han, C., Kaspi, S., Lee, C.-U., Mallia, F., Natusch, T., Pogge, R. W., Park, B.-G., Abe, F., Bond, I. A., Botzler, C. S., Fukui, A., Hearnshaw, J. B., Itow, Y., Kamiya, K., Korpela, A. V., Kilmartin, P. M., Lin, W., Masuda, K., Matsubara, Y., Motomura, M., Muraki, Y., Nakamura, S., Okumura, T., Ohnishi, K., Rattenbury, N. J., Sako, T., Saito, To., Sato, S., Skuljan, L., Sullivan, D. J., Sumi, T., Sweatman, W. L., Yock, P. C. M., Albrow, M. D., Allan, A., Beaulieu, J.-P., Burgdorf, M. J., Cook, K. H., Coutures, C., Dominik, M., Dieters, S., Fouqué, P., Greenhill, J., Horne, K., Steele, I., Tsapras, Y., Chaboyer, B., Crocker, A., Frank, S., and Macintosh, B.

Published
2008
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34. An analysis of binary microlensing event OGLE-2015-BLG-0060

Author

Tsapras, Y., Cassan, A., Ranc, C., Bachelet, E., Street, R., Udalski, A., Hundertmark, M., Bozza, V., Beaulieu, J. P., Marquette, J. B., Euteneuer, E., Figuera Jaimes, R., Calchi Novati, S., Bramich, D. M., Dominik, M., Jaimes, R. Figuera, Horne, K., Mao, S., Menzies, J., Schmidt, R., Snodgrass, C., Steele, I. A., Wambsganss, J., Mróz, P., Szymański, M. K., Soszyński, I., Skowron, J., Pietrukowicz, P., Kozłowski, S., Poleski, R., Ulaczyk, K., PAWLAK, M., Jørgensen, U. G., Skottfelt, J., Popovas, A., Ciceri, S., Korhonen, H., Kuffmeier, M., Evans, D. F., Peixinho, N., Hinse, T. C., Burgdorf, M. J., Southworth, J., Tronsgaard, R., Kerins, E., Andersen, M. I., Rahvar, S., Wang, Y., Wertz, O., Rabus, M., Novati, S. Calchi, D'Ago, G., Scarpetta, G., Mancini, L., Abe, F., Asakura, Y., Bennett, D. P., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Hirao, Y., Itow, Y., Kawasaki, K., Koshimoto, N., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Miyazaki, S., Nagakane, M., Ohnishi, K., Rattenbury, N., Saito, T. O., Sharan, A., Shibai, H., Sullivan, D. J., Sumi, T., Suzuki, D., Tristram, P. J., Yamada, T., Yonehara, A., Figuera Jaimes, R, Calchi Novati, S, D’Ago, G, Jaimes, R Figuera, Novati, S Calchi, Astronomische Rechen-Institut [Heidelberg] (ARI), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg]-Universität Heidelberg [Heidelberg], M2A 2019, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Senckenberg Institute, Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science [Washington], NSF Center for EUV Science and Technology, NSF, Ifremer (COP), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), CSNSM PCI, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), School of Chemical and Physical Sciences [Keele], Keele University [Keele], Okayama Astrophysical Observatory, National Astronomical Observatory of Japan (NAOJ), Department of Materials Science [Tokyo], Tokyo Institute of Technology [Tokyo] (TITECH), Laboratory for Intelligent Systems and Informatics, Department of Mechano-Informatics Graduate School of Information Science and Technology, University of Tokyo, Tokyo, Japan (ISI laboratory), University of Tokyo (UTokyo), Atmosphere and Ocean Research Institute [Kashiwa-shi] (AORI), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), NASA Goddard Space Flight Center (GSFC), Astronomical Observatory [Warsaw], Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW)-University of Warsaw (UW), Space Science Department of ESA, European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Max-Planck-Institut für Astronomie (MPIA), Ohio State University [Columbus] (OSU), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Kuopio Unit [FMI], Finnish Meteorological Institute (FMI), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (KU), Argelander Institute for Astronomy (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Instituto de Astrofisica de Canarias (IAC), Nagoya University, Department of Physics [Notre Dame], University of Notre Dame [Indiana] (UND), University of Auckland [Auckland], Osaka University [Osaka], Tokyo University of Science [Tokyo], Department of Chemistry, Université de Tsukuba = University of Tsukuba, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Space Science [Toyonaka-shi], Osaka University, Tokyo University Sci. Dept. Sci. & Technol., The University of Tokyo (UTokyo), Science & Technology Facilities Council, University of St Andrews. St Andrews Centre for Exoplanet Science, University of St Andrews. School of Physics and Astronomy, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), University of Copenhagen = Københavns Universitet (UCPH), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
GRAVITATIONAL LENS, T-EFF, Event (relativity), observational [methods], Binary number, Galaxy: Bulge, gravitational lensing: Micro, methods: Observational, techniques: Photometric, Astrophysics, gravitational lensing: micro, GALACTIC BULGE, 01 natural sciences, Galaxy: bulge, photometric [techniques], techniques: photometric, Bulge, Observatory, QB Astronomy, NETWORK, 010303 astronomy & astrophysics, QC, ComputingMilieux_MISCELLANEOUS, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), MILKY-WAY, Astrophysics::Earth and Planetary Astrophysics, methods: observational, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], bulge [Galaxy], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, Settore FIS/05 - Astronomia e Astrofisica, SYSTEMS, SEARCH, 0103 physical sciences, ALGORITHM, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, 010308 nuclear & particles physics, Order (ring theory), DAS, Astronomy and Astrophysics, Light curve, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], QC Physics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], DISCOVERY, astro-ph.EP, micro [gravitational lensing], Parallax, astro-ph.IM, Astrophysics - Earth and Planetary Astrophysics, PLANETS, QB799
Abstract

We present the analysis of stellar binary microlensing event OGLE-2015-BLG-0060 based on observations obtained from 13 different telescopes. Intensive coverage of the anomalous parts of the light curve was achieved by automated follow-up observations from the robotic telescopes of the Las Cumbres Observatory. We show that, for the first time, all main features of an anomalous microlensing event are well covered by follow-up data, allowing us to estimate the physical parameters of the lens. The strong detection of second-order effects in the event light curve necessitates the inclusion of longer-baseline survey data in order to constrain the parallax vector. We find that the event was most likely caused by a stellar binary-lens with masses $M_{\star1} = 0.87 \pm 0.12 M_{\odot}$ and $M_{\star2} = 0.77 \pm 0.11 M_{\odot}$. The distance to the lensing system is 6.41 $\pm 0.14$ kpc and the projected separation between the two components is 13.85 $\pm 0.16$ AU. Alternative interpretations are also considered., Comment: 13 pages, 5 figures, Published in MNRAS

Published
2019

35. The January 2016 eruption of recurrent nova LMC 1968

Author

Kuin, N P M, Page, K L, Mróz, P, Darnley, M J, Shore, S N, Osborne, J P, Walter, F, Di Mille, F, Morrell, N, Munari, U, Bohlsen, T, Evans, A, Gehrz, R D, Starrfield, S, Henze, M, Williams, S C, Schwarz, G J, Udalski, A, Szymański, M K, Poleski, R, Soszyński, I, Ribeiro, V A R M, Angeloni, R, Breeveld, A A, Beardmore, A P, and Skowron, J

Subjects
novae, cataclysmic variables – stars: individual (Nova LMC 1968) – ultraviolet: stars – X-rays: binaries – binaries: eclipsing, novae, cataclysmic variables – stars: individual (Nova LMC 1968) – ultraviolet: stars – X-rays: binaries – binaries: eclipsing
Published
2019

36. Search for Low-Mass Exoplanets by Gravitational Microlensing at High Magnification

Author

Abe, F., Bennett, D. P., Bond, I. A., Eguchi, S., Furuta, Y., Hearnshaw, J. B., Kamiya, K., Kilmartin, P. M., Kurata, Y., Masuda, K., Matsubara, Y., Muraki, Y., Noda, S., Okajima, K., Rakich, A., Rattenbury, N. J., Sako, T., Sekiguchi, T., Sullivan, D. J., Sumi, T., Tristram, P. J., Yanagisawa, T., Yock, P. C. M., Gal-Yam, A., Lipkin, Y., Maoz, D., Ofek, E. O., Udalski, A., Szewczyk, O., Żebruń, K., Soszyński, I., Szymański, M. K., Kubiak, M., Pietrzyński, G., and Wyrzykowski, L.

Published
2004

38. The First Planetary Microlensing Event with Two Microlensed Source Stars

Author

Bennett, D. P., Udalski, A., Han, C., Bond, I. A., Beaulieu, J.-P., Skowron, J., Gaudi, B. S., Koshimoto, N., Abe, F., Asakura, Y., Barry, R. K., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Hirao, Y., Itow, Y., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Nagakane, M., Ohnishi, K., Oyokawa, H., Ranc, C., Rattenbury, N. J., Rosenthal, M. M., Saito, To., Sharan, A., Sullivan, D. J., Sumi, T., Suzuki, D., Tristram, P. J., Yonehara, A., The MOA Collaboration, Szymański, M. K., Poleski, R., Soszyński, I., Ulaczyk, K., Wyrzykowski, Ł., The OGLE Collaboration, DePoy, D., Gould, A., Pogge, R. W., Yee, J. C., The μFUN Collaboration, Albrow, M. D., Bachelet, E., Batista, V., Bowens- Rubin, R., Brillant, S., Caldwell, J. A. R., Cole, A., Coutures, C., Dieters, S., Dominis Prester, Dijana, Donatowicz, J., Fouqué, P., Horne, K., Hundertmark, M., Kains, N., Kane, S. R., Marquette, J.- B., Menzies, J., Pollard, K. R., Sahu, K. C., Wambsganss, J., Williams, A., and Zub, M.

Subjects
gravitational lensin, micro, planetary systems, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present the analysis of the microlensing event MOA-2010-BLG-117, and show that the light curve can only be explained by the gravitational lensing of a binary source star system by a star with a Jupiter-mass ratio planet. It was necessary to modify standard microlensing modeling methods to find the correct light curve solution for this binary source, binary-lens event. We are able to measure a strong microlensing parallax signal, which yields the masses of the host star, M * = 0.58 ± 0.11 M ⊙, and planet, m p = 0.54 ± 0.10M Jup, at a projected star– planet separation of a ⊥ = 2.42 ± 0.26 au, corresponding to a semimajor axis of a=2.9≥nfrac{; ; ; ; ; ; ; }; ; ; ; ; ; ; {; ; ; ; ; ; ; }; ; ; ; ; ; ; {; ; ; ; ; ; ; 0em}; ; ; ; ; ; ; {; ; ; ; ; ; ; }; ; ; ; ; ; ; {; ; ; ; ; ; ; +1.6}; ; ; ; ; ; ; {; ; ; ; ; ; ; -0.6}; ; ; ; ; ; ; au. Thus, the system resembles a half-scale model of the Sun–Jupiter system with a half- Jupiter0mass planet orbiting a half- solar-mass star at very roughly half of Jupiter’s orbital distance from the Sun. The source stars are slightly evolved, and by requiring them to lie on the same isochrone, we can constrain the source to lie in the near side of the bulge at a distance of D S = 6.9 ± 0.7 kpc, which implies a distance to the planetary lens system of D L = 3.5 ± 0.4 kpc. The ability to model unusual planetary microlensing events, like this one, will be necessary to extract precise statistical information from the planned large exoplanet microlensing surveys, such as the WFIRST microlensing survey.

Published
2018

39. OGLE-2017-BLG-0039: Microlensing Event with Light from a Lens Identified from Mass Measurement

Author

Han, C., Jung, Y. K., Udalski, A., Bond, I., Bozza, V., The, KMTNet Collaboration, Albrow, M. D., Chung, S.-J., Gould, A., Hwang, K.-H., Kim, D., Lee, C.-U., Kim, H.-W., Ryu, Y.-H., Shin, I.-G., Yee, J. C., Shvartzvald, Y., Cha, S.-M., Kim, S.-L., Kim, D.-J., Lee, D.-J., Lee, Y., Park, B.-G., Pogge, R. W., The, OGLE Collaboration Szymański M. K., Mróz, P., Skowron, J., Poleski, R., Soszyński, I., Kozłowski, S., Pietrukowicz, P., Ulaczyk, K., Pawlak, M., The, MOA Collaboration Abe F., Barry, R., Bennett, D. P., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Hirao, Y., Itow, Y., Kawasaki, K., Koshimoto, N., Li, M. C. A., Ling, C. H., Matsubara, Y., Miyazaki, S., Munakata, H., Muraki, Y., Nagakane, M., Ohnishi, K., Ranc, C., Rattenbury, N., Saito, T., Sharan, A., Sullivan, D. J., Sumi, T., Suzuki, Daisuke, Tristram, P. J., Yamada, T., and Yonehara, A.

Subjects
Brightness, 010504 meteorology & atmospheric sciences, Event (relativity), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, gravitational lensing: micro, Gravitational microlensing, 01 natural sciences, Einstein radius, law.invention, law, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, Astronomy and Astrophysics, binaries: general, Space and Planetary Science, Lens (optics), Stars, Astrophysics - Solar and Stellar Astrophysics, Caustic (optics), Astrophysics::Earth and Planetary Astrophysics, Parallax
Abstract

著者人数: 61名（所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 鈴木, 大介), Accepted: 2018-09-27, 資料番号: SA1180205000

Published
2018

40. Accurate stellar parameters and distance to two evolved eclipsing binary systems, OGLE-BLG-ECL-123903 and OGLE-BLG-ECL-296596, towards the Galactic bulge.

Author

Suchomska, K., Graczyk, D., Pietrzyński, G., Gieren, W., Ostrowski, J., Smolec, R., Tkachenko, A., Górski, M., Karczmarek, P., Wielgórski, P., Zgirski, B., Thompson, I. B., Villanova, S., Pilecki, B., Taormina, M., Kołaczkowski, Z., Narloch, W., and Soszyński, I.

Subjects
STAR formation, PARAMETERS (Statistics), ACTIVE galactic nuclei, GALAXIES, REDSHIFT
Abstract

Aims. Our aim is to obtain high-accuracy measurements of the physical and orbital parameters of two evolved eclipsing binary systems, and to use these measurements to study their evolutionary status. We also aim to derive the distances to the systems by using a surface brightness–colour relation and compare these distances with the measurements provided by Gaia. Methods. We measured the physical and orbital parameters of both systems based on V-band and I-band photometry from OGLE, near-infrared photometry obtained with the NTT telescope and the instrument SOFI, as well as high-resolution spectra obtained at ESO 3.6m/HARPS and Clay 6.5/MIKE spectrographs. The light curves and radial-velocity curves were analysed with the Wilson–Devinney code. Results. We analysed two double-lined eclipsing binary systems OGLE-BLG-ECL-123903 and OGLE-BLG-ECL-296596 from the Optical Gravitational Lensing Experiment (OGLE) catalogue. Both systems have a configuration of two well-detached giants stars. The masses of the components of OGLE-BLG-ECL-123903 are M1 = 2.045 ± 0.027 and M2 = 2.074 ± 0.023 M⊙ and the radii are R1 = 9.540 ± 0.049 and R2 = 9.052 ± 0.060 R⊙. For OGLE-BLG-ECL-296596, the masses are M1 = 1.093 ± 0.015 and M2 = 1.125 ± 0.014 M⊙, while the radii are R1 = 18.06 ± 0.28 and R2 = 29.80 ± 0.33 R⊙. Evolutionary status was discussed based on the isochrones and evolutionary tracks from PARSEC and MESA codes. The ages of the systems were established to be around 1.3 Gyr for the OGLE-BLG-ECL-123903 and 7.7 Gyr for the OGLE-BLG-ECL-296596. We also determined the distance to both systems. For OGLE-BLG-ECL-123903 this is equal to d = 2.95 ± 0.06 (stat.) ±0.07 (syst.) kpc, while for the OGLE-BLG-ECL-296596 it is d = 5.68 ± 0.07 (stat.) ±0.14 (syst.) kpc. This is the first analysis of its kind for these unique evolved eclipsing binary systems. [ABSTRACT FROM AUTHOR]

Published
2019
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41. Frequency analysis of the first-overtone RR Lyrae stars based on Extended Aperture Photometry from K2 data.

Author

Netzel, H., Molnár, L., Plachy, E., and Benkő, J. M.

Subjects
RR Lyrae stars, PULSATING stars, PHOTOMETRY, OPTICAL modulation, STELLAR oscillations, CEPHEIDS, ASTRONOMICAL photometry
Abstract

Context. Additional low-amplitude signals have been observed in many RR Lyrae stars separate from pulsations in radial modes. The most common of these are short-period signals forming a period ratio of around 0.60–0.65 with the first overtone and long-period signals forming a period ratio of around 0.68. The RR Lyrae stars may also exhibit quasi-periodic modulation in their light curves, the so-called Blazhko effect. Aims. We used the extensive sample of the first-overtone RR Lyrae stars observed by the Kepler telescope during the K2 mission to search for and characterize additional low-amplitude signals. The K2 data provides space-based photometry for a statistically significant sample. Hence, this data is excellent for studying the pulsation properties of RR Lyrae stars in detail. Methods. We used K2 space-based photometry for RR Lyrae candidates from Campaigns 0–19. We selected RR Lyrae stars pulsating in the first overtone and performed a frequency analysis for each star to characterize their frequency contents. Results. We classified 452 stars as first-overtone RR Lyrae. From that sample, we selected 281 RR0.61 stars, 67 RR0.68 stars, and 68 Blazhko stars. We found particularly interesting stars that show all of the above phenomena simultaneously. We detected signals in RR0.61 stars that form period ratios lower than those observed for the majority of stars of this type. These signals likely form a new sequence in the Petersen diagram, around a period ratio of 0.60. In 32 stars, we detected additional signals that form a period ratio close to that expected in RRd stars, but the classification of these stars as RRd is uncertain. We also report a discovery of additional signals in eight stars that form a new group in the Petersen diagram around the period ratio of 0.465–0.490. The nature of this periodicity remains unknown. [ABSTRACT FROM AUTHOR]

Published
2023
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42. Ground-based Parallax Confirmed by Spitzer: Binary Microlensing Event MOA-2015-BLG-02

Author

Wang, Tianshu, Zhu, Wei, Mao, Shude, Bond, I. A., Gould, A., Udalski, A., Sumi, T., Bozza, V., Ranc, C., Cassan, A., Yee, J. C., Han, C., Abe, F., Asakura, Y., Barry, R., Bennett, D. P., Bhattacharya, A., Donachie, M., Evans, P., Fukui, A., Hirao, Y., Itow, Y., Kawasaki, K., Koshimoto, N., Li, M. C. A., Ling, C. H., Masuda, K., Matsubara, Y., Miyazaki, S., Muraki, Y., Nagakane, M., Ohnishi, K., Rattenbury, N., Saito, To., Sharan, A., Shibai, H., Sullivan, D. J., Suzuki, D., Tristram, P. J., Yamada, T., Yonehara, A., KozŁowski, S., Mróz, P., Pawlak, M., Pietrukowicz, P., Poleski, R., Skowron, J., Soszyński, I., Szymański, M. K., Ulaczyk, K., Beichman, C., Bryden, G., Calchi Novati, S., Carey, S., Fausnaugh, M., Gaudi, B. S., Henderson, C. B., Shvartzvald, Y., Wibking, B., Albrow, M. D., Chung, S.-J., Hwang, K.-H., Jung, Y. K., Ryu, Y.-H., Shin, I.-G., Cha, S.-M., Kim, D.-J., Kim, H.-W., Kim, S.-L., Lee, C.-U., Lee, Y., Park, B.-G., Pogge, R. W., Street, R. A., Tsapras, Y., Hundertmark, M., Bachelet, E., Dominik, M., Horne, K., Jaimes, R. Figuera, Wambsganss, J., Bramich, D. M., Schmidt, R., Snodgrass, C., Steele, I. A., and Menzies, J.

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

e present the analysis of the binary gravitational microlensing event MOA-2015-BLG-020. The event has a fairly long timescale (˜63 days) and thus the light curve deviates significantly from the lensing model that is based on the rectilinear lens-source relative motion. This enables us to measure the microlensing parallax through the annual parallax effect. The microlensing parallax parameters constrained by the ground-based data are confirmed by the Spitzer observations through the satellite parallax method. By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing, the physical parameters of the lens are determined. It is found that the binary lens is composed of two dwarf stars with masses {M}1=0.606+/- 0.028 {M}⊙ and {M}2=0.125 +/- 0.006 {M}⊙ in the Galactic disk. Assuming that the source star is at the same distance as the bulge red clump stars, we find the lens is at a distance {D}L=2.44+/- 0.10 {kpc}. We also provide a summary and short discussion of all of the published microlensing events in which the annual parallax effect is confirmed by other independent observations.

Published
2017

43. Erratum: The Cluster Ages Experiment (CASE) -- VIII. Age and distance of the Globular Cluster 47 Tuc from the analysis of two detached eclipsing binaries.

Author

Thompson, I B, Udalski, A, Dotter, A, Rozyczka, M, Schwarzenberg-Czerny, A, Pych, W, Beletsky, Y, Burley, G S, Marshall, J L, McWilliam, A, Morrell, N, Osip, D, Monson, A, Persson, S E, Szymański, M K, Soszyński, I, Poleski, R, Ulaczyk, K, Wyrzykowski, Ł, and Kozłowski, S

Subjects
GLOBULAR clusters, ECLIPSING binaries, COSMOCHRONOLOGY, AGE differences
Published
2020
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44. The Cluster AgeS Experiment (CASE) – VIII. Age and distance of the Globular Cluster 47 Tuc from the analysis of two detached eclipsing binaries.

Author

Thompson, I B, Udalski, A, Dotter, A, Rozyczka, M, Schwarzenberg-Czerny, A, Pych, W, Beletsky, Y, Burley, G S, Marshall, J L, McWilliam, A, Morrell, N, Osip, D, Monson, A, Persson, S E, Szymański, M K, Soszyński, I, Poleski, R, Ulaczyk, K, Wyrzykowski, Ł, and Kozłowski, S

Subjects
GLOBULAR clusters, ECLIPSING binaries, PARALLAX, DISTANCES, COSMOCHRONOLOGY, DATA analysis
Abstract

We use photometric and spectroscopic observations of the eclipsing binary E32 in the globular cluster 47 Tuc to derive the masses, radii, and luminosities of the component stars. The system has an orbital period of 40.9 d, a markedly eccentric orbit with e  = 0.24, and is shown to be a member of or a recent escaper from the cluster. We obtain |$M_{\rm p} = 0.862\pm 0.005 \, \mathrm{M}_\odot$|⁠ , |$R_{\rm p} = 1.183\pm 0.003 \, \mathrm{R}_\odot$|⁠ , |$L_{\rm p} = 1.65\pm 0.05 \, \mathrm{L}_\odot$| for the primary and |$M_{\rm s} = 0.827\pm 0.005 \, \mathrm{M}_\odot$|⁠ , |$R_{\rm s} = 1.004\pm 0.004 \, \mathrm{R}_\odot$|⁠ , |$L_{\rm s} = 1.14\pm 0.04\, \mathrm{L}_\odot$| for the secondary. Based on these data and on an earlier analysis of the binary V69 in 47 Tuc, we measure the distance to the cluster from the distance moduli of the component stars, and, independently, from a colour – surface brightness calibration. We obtain 4.55 ± 0.03 and 4.50 ± 0.07 kpc, respectively – values compatible within 1 |$\, \sigma$| with recent estimates based on Gaia DR2 parallaxes. By comparing the M – R diagram of the two binaries and the colour–magnitude diagram of 47 Tuc to Dartmouth model isochrones we estimate the age of the cluster to be 12.0 ± 0.5 Gyr, and the helium abundance of the cluster to be Y ≈ 0.25. [ABSTRACT FROM AUTHOR]

Published
2020
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45. Discovery of a very young high-mass X-ray binary associated with the supernova remnant MCSNR J0513-6724 in the LMC.

Author

Maitra, C, Haberl, F, Filipović, M D, Udalski, A, Kavanagh, P J, Carpano, S, Maggi, P, Sasaki, M, Norris, R P, O'Brien, A, Hotan, A, Lenc, E, Szymański, M K, Soszyński, I, Poleski, R, Ulaczyk, K, Pietrukowicz, P, Kozłowski, S, Skowron, J, and Mróz, P

Subjects
SUPERNOVA remnants, LARGE magellanic cloud, X-ray binaries, X-ray spectra, MAGNETIC fields, LIGHT curves, GALACTIC X-ray sources
Abstract

We report the discovery of a very young high-mass X-ray binary (HMXB) system associated with the supernova remnant (SNR) MCSNR J0513-6724 in the Large Magellanic Cloud (LMC), using XMM–Newton X-ray observations. The HMXB is located at the geometrical centre of extended soft X-ray emission, which we confirm as an SNR. The HMXB spectrum is consistent with an absorbed power law with spectral index ∼1.6 and a luminosity of 7 × 1033 erg s−1 (0.2–12 keV). Tentative X-ray pulsations are observed with a periodicity of 4.4 s and the OGLE I -band light curve of the optical counterpart from more than 17.5 yr reveals a period of 2.2324 ± 0.0003 d, which we interpret as the orbital period of the binary system. The X-ray spectrum of the SNR is consistent with non-equilibrium shock models as expected for young/less evolved SNRs. From the derived ionization time-scale we estimate the age of the SNR to be <6 kyr. The association of the HMXB with the SNR makes it the youngest HMXB, in the earliest evolutionary stage known to date. An HMXB as young as this can switch on as an accreting pulsar only when the spin period has reached a critical value. Under this assumption, we obtain an upper limit to the magnetic field of <5 × 1011 G. This implies several interesting possibilities including magnetic field burial, possibly by an episode of post-supernova hyper-critical accretion. Since these fields are expected to diffuse out on a time-scale of 103–104 yr, the discovery of a very young HMXB can provide us the unique opportunity to observe the evolution of the observable magnetic field for the first time in X-ray binaries. [ABSTRACT FROM AUTHOR]

Published
2019
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46. Candidates for non-pulsating stars located in the Cepheid instability strip in the Large Magellanic Cloud based on Strömgren photometry.

Author

Narloch, Weronika, Pietrzyński, G, Kołaczkowski, Z, Smolec, R, Górski, M, Kubiak, M, Udalski, A, Soszyński, I, Graczyk, D, Gieren, W, Karczmarek, P, Zgirski, B, Wielgórski, P, Suchomska, K, Pilecki, B, Taormina, M, and Kałuszyński, M

Subjects
LARGE magellanic cloud, CEPHEIDS, GIANT stars, PHOTOMETRY, STARS, GRAVITATIONAL lenses
Abstract

We present candidates for non-pulsating stars lying in the classical Cepheid instability strip based on the Optical Gravitational Lensing Experiment (OGLE) photometric maps combined with Strömgren photometry obtained with the 4.1-m Southern Astrophysical Research (SOAR) telescope, and Gaia Data Release 2 data in four fields in the Large Magellanic Cloud. We selected 19 candidates in total. After analysis of their light curves from OGLE surveys we found that all these stars appear to be photometrically stable at the level of a few mmag. Our results show that non-pulsating stars might constitute to about |$21\!-\!30\, {\rm per\, cent}$| of the whole sample of giant stars located in the classical instability strip. Furthermore, we identified potential candidates for classical Cepheids with hot companions based on their Strömgren colours. [ABSTRACT FROM AUTHOR]

Published
2019
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47. A giant planet beyond the snow line in microlensing event OGLE-2011-BLG-0251

Author

Kains, N., Street, R.A., Choi, J.-Y., Han, C., Udalski, A., Almeida, L.A., Jablonski, F., Tristram, P.J., Jørgensen, Uffe Gråe, Szymański, M.K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Kozłowski, S., Pietrukowicz, P., Ulaczyk, K., Wyrzykowski, Ł., Skowron, J., Tsapras, Y., Alsubai, K.A., Bozza, V., Browne, P., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Dominik, M., Dreizler, S., Fang, X.-S., Grundahl, F., Gu, C.-H., Hardis, S., Harpsøe, Kennet Bomann West, Hessman, F. V., Hinse, T. C., Hornstrup, Allan, Hundertmark, M., Jessen-Hansen, Jens, Kerins, E., Liebig, C., Lund, M., Lundkvist, M., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Sahu, K.C., Scarpetta, G., Skottfelt, J., Snodgrass, C., Southworth, J., Surdej, J., Tregloan-Reed, J., Wambsganss, J., Wertz, O., Bajek, D., Bramich, D.M., Horne, K., Ipatov, S., Steele, I.A., Abe, F., Bennett, D.P., Bond, I.A., Botzler, C.S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Itow, Y., Ling, C.H., Masuda, K., Matsubara, Y, Miyake, N., Muraki, Y., Ohnishi, K., Rattenbury, N., Saito, T., Sullivan, D.J., Sumi, T., Suzuki, D., Suzuki, K., Sweatman, W.L., Takino, S., Wada, K., Yock, P.C.M., Allen, W., Batista, V., Chung, S.-J., Christie, G., Depoy, D.L., Drummond, J., Gaudi, B.S., Gould, A., Henderson, C., Jung, Y.K., Koo, J.-R., Lee, C.-U., McCormick, J., McGregor, D., Muñoz, J.A., Natusch, T., Ngan, H., Park, H., Pogge, R.W., Shin, I.-G., Yee, J., Albrow, M.D., Bachelet, E., Beaulieu, J.-P., Brillant, S., Caldwell, J.A.R., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Dominis Prester, D., Donatowicz, J., Fouqué, P., Greenhill, J., Kane, S.R., Kubas, D., Marquette, J.-B., Martin, R., Meintjes, P., Menzies, J., Pollard, K.R., Williams, A., Wouters, D., Zub, M., Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy

Subjects
planets and satellites: detection, 010504 meteorology & atmospheric sciences, Satellites, bulge [Galaxy], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Discovery, Gravitational microlensing, 01 natural sciences, Galaxy: bulge, Einstein radius, Lens, gravitational lensing: weak, Settore FIS/05 - Astronomia e Astrofisica, Planet, Snow, 0103 physical sciences, gravitational lensing, weak, planets and satellites, detection, planetary systems, Galaxy, bulge, Binary, QB Astronomy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Giant planet, Systems, Search, Astronomy and Astrophysics, Radius, Frequency, Planetary system, Mass ratio, Mass, Light curve, Stars, Algorithm, detection [Planets and satellites], Planetary systems, Space and Planetary Science, Dwarf, Astrophysics::Earth and Planetary Astrophysics, weak [Gravitational lensing], Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing observations towards the Galactic Bulge. Based on detailed modelling of the observed light curve, we find that the lens is composed of two masses with a mass ratio q=1.9 x 10^-3. Thanks to our detection of higher-order effects on the light curve due to the Earth's orbital motion and the finite size of source, we are able to measure the mass and distance to the lens unambiguously. We find that the lens is made up of a planet of mass 0.53 +- 0.21,M_Jup orbiting an M dwarf host star with a mass of 0.26 +- 0.11 M_Sun. The planetary system is located at a distance of 2.57 +- 0.61 kpc towards the Galactic Centre. The projected separation of the planet from its host star is d=1.408 +- 0.019, in units of the Einstein radius, which corresponds to 2.72 +- 0.75 AU in physical units. We also identified a competitive model with similar planet and host star masses, but with a smaller orbital radius of 1.50 +- 0.50 AU. The planet is therefore located beyond the snow line of its host star, which we estimate to be around 1-1.5 AU., 12 pages, 7 figures, 3 tables; A&A in press

Published
2013
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48. OGLE-2012-BLG-0563Lb : a Saturn-mass planet around an M dwarf with the mass constrained by Subaru AO imaging

Author

Fukui, A., Gould, A., Sumi, T., Bennett, D. P., Bond, I. A., Han, C., Suzuki, D., Beaulieu, J.-P., Batista, V., Udalski, A., Street, R. A., Tsapras, Y., Hundertmark, Markus Peter Gerhard, Abe, F., Bhattacharya, A., Freeman, M., Itow, Y., Ling, C. H., Koshimoto, N., Masuda, K., Matsubara, Y., Muraki, Y., Ohnishi, K., Philpott, L. C., Rattenbury, N., Saito, T., Sullivan, D. J., Tristram, P. J., Yonehara, A., Choi, J.-Y., Christie, G. W., DePoy, D. L., Dong, Subo, Drummond, J., Gaudi, B. S., Hwang, K.-H., Kavka, A., Lee, C.-U., McCormick, J., Natusch, T., Ngan, H., Park, H., Pogge, R. W., Shin, I.-G., Tan, T.-G., Yee, J. C., Szymański, M. K., Pietrzyński, G., Soszyński, I., Poleski, R., Kozłowski, S., Pietrukowicz, P., Ulaczyk, K., Wyrzykowski, Ł., Bramich, D. M., Browne, Paul, Dominik, Martin, Horne, Keith Douglas, Ipatov, S., Kains, N., Snodgrass, C., Steele, I. A., The Royal Society, Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy

Subjects
Metallicity, NDAS, FOS: Physical sciences, Astrophysics, Type (model theory), Gravitational microlensing, 01 natural sciences, Planet, 0103 physical sciences, QB Astronomy, 010303 astronomy & astrophysics, QC, QB, Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010308 nuclear & particles physics, photometric [Techniques], Astronomy and Astrophysics, Planetary system, Mass ratio, Light curve, Exoplanet, Planetary systems, detection [Planets and satellites], gaseous planets [Planets and satellites], high angular resolution [Techniques], QC Physics, 13. Climate action, Space and Planetary Science, late-type [Stars], Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio ~1 x 10^{-3}. Intensive photometric observations of a high-magnification microlensing event allow us to detect a clear signal of the planet. Although no parallax signal is detected in the light curve, we instead succeed at detecting the flux from the host star in high-resolution JHK'-band images obtained by the Subaru/AO188 and IRCS instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of a spectroscopic information about the source star obtained during the high-magnification state by Bensby et al., we find that the lens system is located at 1.3^{+0.6}_{-0.8} kpc from us, and consists of an M dwarf (0.34^{+0.12}_{-0.20} M_sun) orbited by a Saturn-mass planet (0.39^{+0.14}_{-0.23} M_Jup) at the projected separation of 0.74^{+0.26}_{-0.42} AU (close model) or 4.3^{+1.5}_{-2.5} AU (wide model). The probability of contamination in the host star's flux, which would reduce the masses by a factor of up to three, is estimated to be 17%. This possibility can be tested by future high-resolution imaging. We also estimate the (J-Ks) and (H-Ks) colors of the host star, which are marginally consistent with a low metallicity mid-to-early M dwarf, although further observations are required for the metallicity to be conclusive. This is the fifth sub-Jupiter-mass (0.2, Comment: 17 pages, 11 figures, an error in Figure 11 in the published version corrected

Published
2015

49. Microlensing Discovery of a Population of Very Tight, Very Low-mass Binary Brown Dwarfs

Author

Choi, J.-Y., Han, C., Udalski, A., Sumi, T., Gaudi, B. S., Gould, A., Bennett, D. P., Dominik, M., Beaulieu, J.-P., Tsapras, Y., Bozza, V., Abe, F., Bond, I. A., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Itow, Y., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Suzuki, K., Sweatman, W. L., Suzuki, D., Takino, S., Tristram, P. J., Wada, K., Yock, P. C. M., The MOA Collaboration, Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Skowron, J., Kozłowski, S., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Pietrukowicz, P., The OGLE Collaboration, Almeida, L. A., DePoy, D. L., Dong, Subo, Gorbikov, E., Jablonski, F., Henderson, C. B., Hwang, K.-H., Janczak, J., Jung, Y.-K., Kaspi, S., Lee, C.-U., Malamud, U., Maoz, D., McGregor, D., Muñoz, J. A., Park, B.-G., Park, H., Pogge, R. W., Shvartzvald, Y., Shin, I.-G., Yee, J. C., The μFUN Collaboration, Alsubai, K. A., Browne, P., Burgdorf, M. J., Calchi Novati, S., Dodds, P., Fang, X.-S., Finet, F., Glitrup, M., Grundahl, F., Gu, S.-H., Hardis, S., Harpsøe, K., Hinse, T. C., Hornstrup, A., Hundertmark, M., Jessen-Hansen, J., Jrgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, M. N., Lundkvist, M., Maier, G., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Snodgrass, C., Southworth, J., Surdej, J., Tregloan-Reed, J., Wambsganss, J., Wertz, O., Zimmer, F., MiNDSTEp Consortium, The, Albrow, M. D., Bachelet, E., Batista, V., Brillant, S., Cassan, A., Cole, A. A., Coutures, C., Dieters, S., Dominis Prester, D., Donatowicz, J., Fouqué, P., Greenhill, J., Kubas, D., Marquette, J.-B., Menzies, J. W., Sahu, K. C., Zub, M., The PLANET Collaboration, Bramich, D. M., Horne, K., Steele, I. A., Street, R. A., The RoboNet Collaboration, Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy

Subjects
binaries: general, gravitational lensing: micro, 010504 meteorology & atmospheric sciences, Population, Events, Brown dwarf, Minimum mass, Binary number, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Gravitational microlensing, 01 natural sciences, micro [Gravitational lensing], Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, QB, Physics, education.field_of_study, Galactic bulge, general [Binaries], Systems, Search, Astronomy and Astrophysics, Stars, Extrasolar planets, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Low Mass, Gravitational lens
Abstract

Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minimum mass of the brown-dwarf mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low-mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 Msun and 0.034 Msun, and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field brown-dwarf binaries known. The discovery of a population of such binaries indicates that brown dwarf binaries can robustly form at least down to masses of ~0.02 Msun. Future microlensing surveys will measure a mass-selected sample of brown-dwarf binary systems, which can then be directly compared to similar samples of stellar binaries., 7 pages, 5 figures, 3 tables, ApJ submitted

Published
2013

50. The VLT-FLAMES Tarantula survey: XX. The nature of the X-ray bright emission-line star VFTS 399⋆

Author

Clark, J S, Bartlett, E S, Broos, P S, Townsley, L K, Taylor, W D, Walborn, N R, Bird, A J, Sana, H, de Mink, S E, Dufton, P L, Evans, C J, Langer, N, Maíz Apellániz, J, Schneider, F R N, Soszyński, I, Department of Astronomy, and Faculty of Science

Subjects
région, Astrophysics::High Energy Astrophysical Phenomena, preuve, population, nature, Astrophysics::Cosmology and Extragalactic Astrophysics, analyse comparative, partage, classification, Assomption, cohorte, Astrophysics::Solar and Stellar Astrophysics, messe, Astrophysics::Earth and Planetary Astrophysics, prospection, Astrophysics::Galaxy Astrophysics
Abstract

Context: The stellar population of the 30 Doradus star-forming region in the Large Magellanic Cloud contains a subset of apparently single, rapidly rotating O-type stars. The physical processes leading to the formation of this cohort are currently uncertain. Aims. One member of this group, the late O-type star VFTS 399, is found to be unexpectedly X-ray bright for its bolometric luminosity − in this study we aim to determine its physical nature and the cause of this behaviour. Methods. To accomplish this we performed a time-resolved analysis of optical, infrared and X-ray observations. Results. We found VFTS 399 to be an aperiodic photometric variable with an apparent near-IR excess. Its optical spectrum demonstrates complex emission profiles in the lower Balmer series and select He i lines − taken together these suggest an OeBe classification. The highly variable X-ray luminosity is too great to be produced by a single star, while the hard, non-thermal nature suggests the presence of an accreting relativistic companion. Finally, the detection of periodic modulation of the X-ray lightcurve is most naturally explained under the assumption that the accretor is a neutron star. Conclusions. VFTS 399 appears to be the first high-mass X-ray binary identified within 30 Dor, sharing many observational characteristics with classical Be X-ray binaries. Comparison of the current properties of VFTS 399 to binary-evolution models suggests a progenitor mass 25 M for the putative neutron star, which may host a magnetic field comparable in strength to those of magnetars. VFTS 399 is now the second member of the cohort of rapidly rotating “single” O-type stars in 30 Dor to show evidence of binary interaction resulting in spin-up, suggesting that this may be a viable evolutionary pathway for the formation of a subset of this stellar population.

Published
2015
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