Search

Your search keyword '"Mennickent, R."' showing total 623 results
Start Over Author "Mennickent, R."
623 results on '"Mennickent, R."'

101. A Direct Distance to the LMC Cepheid HV 12198 from the Infrared Surface Brightness Technique

Author

Gieren, W. P., Storm, J., Fouque, P., Mennickent, R. E., and Gomez, M.

Subjects
Astrophysics
Abstract

We report on a first application of the infrared surface brightness technique on a Cepheid in the Large Magellanic Cloud, the variable HV 12198 in the young globular cluster NGC 1866. From this one star, we determine a distance modulus of 18.42 +- 0.10 (random and systematic uncertainty) to the cluster. When the results on further member Cepheids in NGC 1866 become available, we expect to derive the distance to the LMC with a +- 3-4 percent accuracy, including systematic errors, from this technique., Comment: 4 pages, 4 figures, accepted in ApJ Letters

Published
2000
Full Text
View/download PDF

102. The dwarf nova RZ Leonis : photometric period, 'anti-humps' and normal alpha disk

Author

Mennickent, R. E., Sterken, C., Gieren, W., and Unda, E.

Subjects
Astrophysics
Abstract

We present results of differential photometry of the dwarf nova RZ Leonis spanning a 11-year baseline. The most striking feature of the light curve is a non-coherent periodic hump of variable amplitude. A seasonal time series analysis yields a photometric period of 0.0756(12) d. In addition, low amplitude fluctuations of the mean magnitude in time scale of months are observed. We find that the hump's amplitude is anti-correlated with the star's mean magnitude and becomes "negative" (i.e. an absorption feature or "anti-hump") when the system is very faint. Secondary humps and "anti-humps" are also observed. The transition from "anti-humps" to fully developed humps occurs on a time scale of 70 days. We interprete the observations as a rapid response of the accretion disk to the increase of mass transfer rate. In this case we deduce a viscosity parameter alpha ~ 0.08, i.e. much larger than often claimed for WZ Sge-like stars. We note that the secondary star in RZ Leo is close to a main-sequence red dwarf and not a brown-dwarf like star as suggested for other long cycle-length SU UMa stars like WZ Sge and V592 Her. Our results indicate that large amplitude and long cycle length dwarf novae might not necessarily correspond to objects in the same evolutive stage., Comment: 10 pages, 11 figures, Astronomy and Astrophysics, accepted

Published
1999

105. Detailed stellar activity analysis and modelling of GJ 832

Author

Gorrini, P., Astudillo-Defru, N., Dreizler, S., Damasso, M., Díaz, R. F., Bonfils, X., Jeffers, S. V., Barnes, J. R., Del Sordo, F., Almenara, J.-M., Artigau, E., Bouchy, F., Charbonneau, D., Delfosse, X., Doyon, R., Figueira, P., Forveille, T., Haswell, C. A., López-González, M. J., Melo, C., Mennickent, R. E., Gaisné, G., Morales, N. Morales, Murgas, F., Pepe, F., Rodríguez, E., Santos, N. C., Tal-Or, L., Tsapras, Y., and Udry, S.

Abstract

Context. Gliese-832 (GJ 832) is an M2V star hosting a massive planet on a decade-long orbit, GJ 832b, discovered by radial velocity (RV). Later, a super Earth or mini-Neptune orbiting within the stellar habitable zone was reported (GJ 832c). The recently determined stellar rotation period (45.7 ± 9.3 days) is close to the orbital period of putative planet c (35.68 ± 0.03 days).\ud \ud Aims. We aim to confirm or dismiss the planetary nature of the RV signature attributed to GJ 832c, by adding 119 new RV data points, new photometric data, and an analysis of the spectroscopic stellar activity indicators. Additionally, we update the orbital parameters of the planetary system and search for additional signals.\ud \ud Methods. We performed a frequency content analysis of the RVs to search for periodic and stable signals. Radial velocity time series were modelled with Keplerians and Gaussian process (GP) regressions alongside activity indicators to subsequently compare them within a Bayesian framework.\ud \ud Results. We updated the stellar rotational period of GJ 832 from activity indicators, obtaining 37.5+1.4-1.5 days, improving the precision by a factor of 6. The new photometric data are in agreement with this value. We detected an RV signal near 18 days (FAP < 4.6%), which is half of the stellar rotation period. Two Keplerians alone fail at modelling GJ 832b and a second planet with a 35-day orbital period. Moreover, the Bayesian evidence from the GP analysis of the RV data with simultaneous activity indices prefers a model without a second Keplerian, therefore negating the existence of planet c.

Published
2022

106. Cyclic changes in the interacting binary RX Cassiopeiae

Author

Mennickent, R. E., primary, Djurašević, G., additional, Petrović, J., additional, Gorrini, P., additional, Burgos, F., additional, Jurkovic, M. I., additional, Magalhaes, A. M., additional, Schleicher, D., additional, and Calderón, P., additional

Published
2022
Full Text
View/download PDF

109. Spectroscopy of the massive interacting binary UU Cassiopeiae

Author

Hadrava, P., primary, Cabezas, M., additional, Djurašević, G., additional, Garcés, J., additional, Gorda, S. Y., additional, Jurkovic, M. I., additional, Korčáková, D., additional, Markov, H., additional, Mennickent, R. E., additional, Petrović, J., additional, Vince, I., additional, and Zharikov, S., additional

Published
2022
Full Text
View/download PDF

111. Detailed stellar activity analysis and modelling of GJ 832: Reassessment of the putative habitable zone planet GJ 832c

Author

Ministerio de Ciencia e Innovación (España), European Commission, Gorrini, P., Astudillo-Defru, N., Dreizler, S., Damasso, M., Díaz, R. F., Bonfils, Xavier, Jeffers, Sandra V., Barnes, John R., Del Sordo, F., Almenara, J. -M., Artigau, E., Bouchy, F., Charbonneau, D., Delfosse, X., Doyon, R., Figueira, P., Forveille, T., Haswell, C. A., López González, Maria J., Melo, C., Mennickent, R. E., Gaisné, G., Morales, Nicolás, Murgas, F., Pepe, F., Rodríguez Martínez, Eloy, Santos, N. C., Tal-Or, L., Tsapras, Y., Udry, Stephane, Ministerio de Ciencia e Innovación (España), European Commission, Gorrini, P., Astudillo-Defru, N., Dreizler, S., Damasso, M., Díaz, R. F., Bonfils, Xavier, Jeffers, Sandra V., Barnes, John R., Del Sordo, F., Almenara, J. -M., Artigau, E., Bouchy, F., Charbonneau, D., Delfosse, X., Doyon, R., Figueira, P., Forveille, T., Haswell, C. A., López González, Maria J., Melo, C., Mennickent, R. E., Gaisné, G., Morales, Nicolás, Murgas, F., Pepe, F., Rodríguez Martínez, Eloy, Santos, N. C., Tal-Or, L., Tsapras, Y., and Udry, Stephane

Abstract

Context. Gliese-832 (GJ 832) is an M2V star hosting a massive planet on a decade-long orbit, GJ 832b, discovered by radial velocity (RV). Later, a super Earth or mini-Neptune orbiting within the stellar habitable zone was reported (GJ 832c). The recently determined stellar rotation period (45.7 ± 9.3 days) is close to the orbital period of putative planet c (35.68 ± 0.03 days). Aims. We aim to confirm or dismiss the planetary nature of the RV signature attributed to GJ 832c, by adding 119 new RV data points, new photometric data, and an analysis of the spectroscopic stellar activity indicators. Additionally, we update the orbital parameters of the planetary system and search for additional signals. Methods. We performed a frequency content analysis of the RVs to search for periodic and stable signals. Radial velocity time series were modelled with Keplerians and Gaussian process (GP) regressions alongside activity indicators to subsequently compare them within a Bayesian framework. Results. We updated the stellar rotational period of GJ 832 from activity indicators, obtaining 37.5+1.4-1.5 days, improving the precision by a factor of 6. The new photometric data are in agreement with this value. We detected an RV signal near 18 days (FAP < 4.6%), which is half of the stellar rotation period. Two Keplerians alone fail at modelling GJ 832b and a second planet with a 35-day orbital period. Moreover, the Bayesian evidence from the GP analysis of the RV data with simultaneous activity indices prefers a model without a second Keplerian, therefore negating the existence of planet c. © P. Gorrini et al. 2022.

Published
2022

115. Masses and compositions of three small planets orbiting the nearby M dwarf L231-32 (TOI-270) and the M dwarf radius valley

Author

Van Eylen, V, primary, Astudillo-Defru, N, additional, Bonfils, X, additional, Livingston, J, additional, Hirano, T, additional, Luque, R, additional, Lam, K W F, additional, Justesen, A B, additional, Winn, J N, additional, Gandolfi, D, additional, Nowak, G, additional, Palle, E, additional, Albrecht, S, additional, Dai, F, additional, Estrada, B Campos, additional, Owen, J E, additional, Foreman-Mackey, D, additional, Fridlund, M, additional, Korth, J, additional, Mathur, S, additional, Forveille, T, additional, Mikal-Evans, T, additional, Osborne, H L M, additional, Ho, C S K, additional, Almenara, J M, additional, Artigau, E, additional, Barragán, O, additional, Barros, S C C, additional, Bouchy, F, additional, Cabrera, J, additional, Caldwell, D A, additional, Charbonneau, D, additional, Chaturvedi, P, additional, Cochran, W D, additional, Csizmadia, S, additional, Damasso, M, additional, Delfosse, X, additional, De Medeiros, J R, additional, Díaz, R F, additional, Doyon, R, additional, Esposito, M, additional, Fűrész, G, additional, Figueira, P, additional, Georgieva, I, additional, Goffo, E, additional, Grziwa, S, additional, Guenther, E, additional, Hatzes, A P, additional, Jenkins, J M, additional, Kabath, P, additional, Knudstrup, E, additional, Latham, D W, additional, Lavie, B, additional, Lovis, C, additional, Mennickent, R E, additional, Mullally, S E, additional, Murgas, F, additional, Narita, N, additional, Pepe, F A, additional, Persson, C M, additional, Redfield, S, additional, Ricker, G R, additional, Santos, N C, additional, Seager, S, additional, Serrano, L M, additional, Smith, A M S, additional, Mascareño, A Suárez, additional, Subjak, J, additional, Twicken, J D, additional, Udry, S, additional, Vanderspek, R, additional, and Osorio, M R Zapatero, additional

Published
2021
Full Text
View/download PDF

118. Masses and compositions of three small planets orbiting the nearby M dwarf L231-32 (TOI-270) and the M dwarf radius valley

Author

Van Eylen, V., Astudillo-Defru, N., Bonfils, X., Livingston, J., Hirano, T., Luque, R., Lam, K. W. F., Justesen, A. B., Winn, J. N., Gandolfi, D., Nowak, G., Palle, E., Albrecht, S., Dai, F., Estrada, B. Campos, Owen, J. E., Foreman-Mackey, D., Fridlund, M., Korth, J., Mathur, S., Forveille, T., Mikal-Evans, T., Osborne, H. L. M., Ho, C. S. K., Almenara, J. M., Artigau, E., Barragan, O., Barros, S. C. C., Bouchy, F., Cabrera, J., Caldwell, D. A., Charbonneau, D., Chaturvedi, P., Cochran, W. D., Csizmadia, S., Damasso, M., Delfosse, X., De Medeiros, J. R., Diaz, R. F., Doyon, R., Esposito, M., Furesz, G., Figueira, P., Georgieva, I, Goffo, E., Grziwa, S., Guenther, E., Hatzes, A. P., Jenkins, J. M., Kabath, P., Knudstrup, E., Latham, D. W., Lavie, B., Lovis, C., Mennickent, R. E., Mullally, S. E., Murgas, F., Narita, N., Pepe, F. A., Persson, C. M., Redfield, S., Ricker, G. R., Santos, N. C., Seager, S., Serrano, L. M., Smith, A. M. S., Suarez Mascareno, A., Subjak, J., Twicken, J. D., Udry, S., Vanderspek, R., Zapatero Osorio, M. R., Van Eylen, V., Astudillo-Defru, N., Bonfils, X., Livingston, J., Hirano, T., Luque, R., Lam, K. W. F., Justesen, A. B., Winn, J. N., Gandolfi, D., Nowak, G., Palle, E., Albrecht, S., Dai, F., Estrada, B. Campos, Owen, J. E., Foreman-Mackey, D., Fridlund, M., Korth, J., Mathur, S., Forveille, T., Mikal-Evans, T., Osborne, H. L. M., Ho, C. S. K., Almenara, J. M., Artigau, E., Barragan, O., Barros, S. C. C., Bouchy, F., Cabrera, J., Caldwell, D. A., Charbonneau, D., Chaturvedi, P., Cochran, W. D., Csizmadia, S., Damasso, M., Delfosse, X., De Medeiros, J. R., Diaz, R. F., Doyon, R., Esposito, M., Furesz, G., Figueira, P., Georgieva, I, Goffo, E., Grziwa, S., Guenther, E., Hatzes, A. P., Jenkins, J. M., Kabath, P., Knudstrup, E., Latham, D. W., Lavie, B., Lovis, C., Mennickent, R. E., Mullally, S. E., Murgas, F., Narita, N., Pepe, F. A., Persson, C. M., Redfield, S., Ricker, G. R., Santos, N. C., Seager, S., Serrano, L. M., Smith, A. M. S., Suarez Mascareno, A., Subjak, J., Twicken, J. D., Udry, S., Vanderspek, R., and Zapatero Osorio, M. R.

Abstract

We report on precise Doppler measurements of L231-32 (TOI-270), a nearby M dwarf (d = 22pc, M-star = 0.39 M-circle dot, R-star = 0.38 R-circle dot), which hosts three transiting planets that were recently discovered using data from the Transiting Exoplanet Survey Satellite (TESS). The three planets are 1.2, 2.4, and 2.1 times the size of Earth and have orbital periods of 3.4, 5.7, and 11.4 d. We obtained 29 high-resolution optical spectra with the newly commissioned Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) and 58 spectra using the High Accuracy Radial velocity Planet Searcher (HARPS). From these observations, we find the masses of the planets to be 1.58 +/- 0.26, 6.15 +/- 0.37, and 4.78 +/- 0.43 M-circle plus, respectively. The combination of radius and mass measurements suggests that the innermost planet has a rocky composition similar to that of Earth, while the outer two planets have lower densities. Thus, the inner planet and the outer planets are on opposite sides of the 'radius valley' - a region in the radius-period diagram with relatively few members - which has been interpreted as a consequence of atmospheric photoevaporation. We place these findings into the context of other small close-in planets orbiting M dwarf stars, and use support vector machines to determine the location and slope of the M dwarf (T-eff < 4000 K) radius valley as a function of orbital period. We compare the location of the M dwarf radius valley to the radius valley observed for FGK stars, and find that its location is a good match to photoevaporation and core-powered mass-loss models. Finally, we show that planets below the M dwarf radius valley have compositions consistent with stripped rocky cores, whereas most planets above have a lower density consistent with the presence of a H-He atmosphere.

Published
2021

124. A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS

Author

Astudillo-Defru, N., primary, Cloutier, R., additional, Wang, S. X., additional, Teske, J., additional, Brahm, R., additional, Hellier, C., additional, Ricker, G., additional, Vanderspek, R., additional, Latham, D., additional, Seager, S., additional, Winn, J. N., additional, Jenkins, J. M., additional, Collins, K. A., additional, Stassun, K. G., additional, Ziegler, C., additional, Almenara, J. M., additional, Anderson, D. R., additional, Artigau, E., additional, Bonfils, X., additional, Bouchy, F., additional, Briceño, C., additional, Butler, R. P., additional, Charbonneau, D., additional, Conti, D. M., additional, Crane, J., additional, Crossfield, I. J. M., additional, Davies, M., additional, Delfosse, X., additional, Díaz, R. F., additional, Doyon, R., additional, Dragomir, D., additional, Eastman, J. D., additional, Espinoza, N., additional, Essack, Z., additional, Feng, F., additional, Figueira, P., additional, Forveille, T., additional, Gan, T., additional, Glidden, A., additional, Guerrero, N., additional, Hart, R., additional, Henning, Th., additional, Horch, E. P., additional, Isopi, G., additional, Jenkins, J. S., additional, Jordán, A., additional, Kielkopf, J. F., additional, Law, N., additional, Lovis, C., additional, Mallia, F., additional, Mann, A. W., additional, de Medeiros, J. R., additional, Melo, C., additional, Mennickent, R. E., additional, Mignon, L., additional, Murgas, F., additional, Nusdeo, D. A., additional, Pepe, F., additional, Relles, H. M., additional, Rose, M., additional, Santos, N. C., additional, Ségransan, D., additional, Shectman, S., additional, Shporer, A., additional, Smith, J. C., additional, Torres, P., additional, Udry, S., additional, Villasenor, J., additional, Winters, J .G., additional, and Zhou, G., additional

Published
2020
Full Text
View/download PDF

125. Binarity among objects with the Be and B[e] phenomena

Author

Miroshnichenko, A.S., primary, Zharikov, S.V., additional, Korčaková, D., additional, Manset, N., additional, Mennickent, R., additional, Khokhlov, S.A., additional, Danford, S., additional, Raj, A., additional, and Zakhozhay, O.V., additional

Published
2020
Full Text
View/download PDF

127. On the long-cycle variability of the Algol OGLE-LMC-DPV-065 and its stellar, orbital, and disc parameters

Author

Mennickent, R. E. (R. E.), Cabezas, M. (M.), Djurašević, G. G. (G. G.), Rivinius, T. (T.), Hadrava, P. (P.), Poleski, R. (R.), Soszyński, I. (I.), Celedón, L. (L.), Astudillo-Defru, N. (N.), Raj, A. (A.), Fernández-Trincado, J. G. (J. G.), Schmidtobreick, L. (L.), Tappert, C. (C.), Neustroev, V. (V.), Porritt, I. (I.), Mennickent, R. E. (R. E.), Cabezas, M. (M.), Djurašević, G. G. (G. G.), Rivinius, T. (T.), Hadrava, P. (P.), Poleski, R. (R.), Soszyński, I. (I.), Celedón, L. (L.), Astudillo-Defru, N. (N.), Raj, A. (A.), Fernández-Trincado, J. G. (J. G.), Schmidtobreick, L. (L.), Tappert, C. (C.), Neustroev, V. (V.), and Porritt, I. (I.)

Abstract

OGLE-LMC-DPV-065 is an interacting binary whose double-hump long photometric cycle remains hitherto unexplained. We analyze photometric time series available in archive data sets spanning 124 yr and present the analysis of new high-resolution spectra. A refined orbital period is found of 10d.031 6267 ± 0d.000 0056 without any evidence of variability. In spite of this constancy, small but significant changes in timings of the secondary eclipse are detected. We show that the long period continuously decreases from 350 to 218 d during 13 yr, then remains almost constant for about 10 yr. Our study of radial velocities indicates a circular orbit for the binary and yields a mass ratio of 0.203 ± 0.001. From the analysis of the orbital light curve, we find that the system contains 13.8 and 2.81 M⊙ stars of radii 8.8 and 12.6 R⊙ and absolute bolometric magnitudes −6.4 and −3.0, respectively. The orbit semimajor axis is 49.9 R⊙ and the stellar temperatures are 25 460 K and 9825 K. We find evidence for an optically and geometrically thick disc around the hotter star. According to our model, the disc has a radius of 25 R⊙, central and outer vertical thickness of 1.6 R⊙ and 3.5 R⊙, and temperature of 9380 K at its outer edge. Two shock regions located at roughly opposite parts of the outer disc rim can explain the light-curve asymmetries. The system is a member of the double periodic variables and its relatively high-mass and long photometric cycle make it similar in some aspects to β Lyrae.

Published
2019

130. Possible evidence for a magnetic dynamo in hot Algols.

Author

Mennickent, R. E., Garcés, J., Djurašević, G., Rojas, G., Schleicher, D., Otero, S., Kosovichev, Alexander, Strassmeier, Klaus, and Jardine, Moira

Abstract

We present the case of hot semi-detached Algols showing photometric cycles longer than the orbital period. The evidence indicating that this long cycle might be due to a magnetic dynamo operating in the rapidly rotating donor star is examined. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

133. The APOGEE-2 Survey of the Orion Star-forming Complex. I. Target Selection and Validation with Early Observations

Author

Cottle, J., Covey, K., Suárez, G., Román-Zúñiga, C., Schlafly, E., Downes, J., Ybarra, J., Hernandez, J., Stassun, K., Stringfellow, G., Getman, K., Feigelson, E., Borissova, J., Kim, J., Roman-Lopes, A., Da Rio, N., De Lee, N., Frinchaboy, P., Kounkel, M., Majewski, S., Mennickent, R., Nidever, D., Nitschelm, C., Pan, K., Shetrone, M., Zasowski, G., Chambers, K., Magnier, E., and Valenti, J.

Abstract

The Orion Star-forming Complex (OSFC) is a central target for the APOGEE-2 Young Cluster Survey. Existing membership catalogs span limited portions of the OSFC, reflecting the difficulty of selecting targets homogeneously across this extended, highly structured region. We have used data from wide-field photometric surveys to produce a less biased parent sample of young stellar objects (YSOs) with infrared (IR) excesses indicative of warm circumstellar material or photometric variability at optical wavelengths across the full 420 square degree extent of the OSFC. When restricted to YSO candidates with H < 12.4, to ensure S/N ̃ 100 for a six-visit source, this uniformly selected sample includes 1307 IR excess sources selected using criteria vetted by Koenig & Liesawitz (2014) and 990 optical variables identified in the Pan-STARRS1 3π survey: 319 sources exhibit both optical variability and evidence of circumstellar disks through IR excess. Objects from this uniformly selected sample received the highest priority for targeting, but required fewer than half of the fibers on each APOGEE-2 plate. We filled the remaining fibers with previously confirmed and new color- magnitude selected candidate OSFC members. Radial velocity measurements from APOGEE-1 and new APOGEE-2 observations taken in the survey’s first year indicate that ̃90% of the uniformly selected targets have radial velocities consistent with Orion membership. The APOGEE-2 Orion survey will include >1100 bona fide YSOs whose uniform selection function will provide a robust sample for comparative analyses of the stellar populations and properties across all sub-regions of Orion.

Published
2018

137. H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia

Author

Fernández-Trincado, J. G., primary, Zamora, O., additional, Souto, Diogo, additional, Cohen, R. E., additional, Dell’Agli, F., additional, García-Hernández, D. A., additional, Masseron, T., additional, Schiavon, R. P., additional, Mészáros, Sz., additional, Cunha, K., additional, Hasselquist, S., additional, Shetrone, M., additional, Schiappacasse Ulloa, J., additional, Tang, B., additional, Geisler, D., additional, Schleicher, D. R. G., additional, Villanova, S., additional, Mennickent, R. E., additional, Minniti, D., additional, Alonso-García, J., additional, Manchado, A., additional, Beers, T. C., additional, Sobeck, J., additional, Zasowski, G., additional, Schultheis, M., additional, Majewski, S. R., additional, Rojas-Arriagada, A., additional, Almeida, A., additional, Santana, F., additional, Oelkers, R. J., additional, Longa-Peña, P., additional, Carrera, R., additional, Burgasser, A. J., additional, Lane, R. R., additional, Roman-Lopes, A., additional, Ivans, I. I., additional, and Hearty, F. R., additional

Published
2019
Full Text
View/download PDF

140. On the long-cycle variability of the Algol OGLE-LMC-DPV-065 and its stellar, orbital, and disc parameters

Author

Mennickent, R E, primary, Cabezas, M, additional, Djurašević, G, additional, Rivinius, T, additional, Hadrava, P, additional, Poleski, R, additional, Soszyński, I, additional, Celedón, L, additional, Astudillo-Defru, N, additional, Raj, A, additional, Fernández-Trincado, J G, additional, Schmidtobreick, L, additional, Tappert, C, additional, Neustroev, V, additional, and Porritt, I, additional

Published
2019
Full Text
View/download PDF

147. Long-term variations in the X-ray activity of HR 1099

Author

Perdelwitz, V., primary, Navarrete, F. H., additional, Zamponi, J., additional, Mennickent, R. E., additional, Völschow, M., additional, Robrade, J., additional, Schneider, P. C., additional, Schleicher, D. R. G., additional, and Schmitt, J. H. M. M., additional

Published
2018
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results