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1. Teegarden's Star revisited: A nearby planetary system with at least three planets

Author

Dreizler, S., Luque, R., Ribas, I., Koseleva, V., Ruh, H. L., Nagel, E., Pozuelos, F. J., Zechmeister, M., Reiners, A., Caballero, J. A., Amado, P. J., Béjar, V. J. S., Bean, J. L., Brady, M., Cifuentes, C., Gillon, M., Hatzes, A. P., Henning, Th., Kasper, D., Montes, D., Morales, J. C., Murray, C. A., Pallé, E., Quirrenbach, A., Seifahrt, A., Schweitzer, A., Stürmer, J., Stefánsson, G., Linares, J. I. Vico, Dreizler, S., Luque, R., Ribas, I., Koseleva, V., Ruh, H. L., Nagel, E., Pozuelos, F. J., Zechmeister, M., Reiners, A., Caballero, J. A., Amado, P. J., Béjar, V. J. S., Bean, J. L., Brady, M., Cifuentes, C., Gillon, M., Hatzes, A. P., Henning, Th., Kasper, D., Montes, D., Morales, J. C., Murray, C. A., Pallé, E., Quirrenbach, A., Seifahrt, A., Schweitzer, A., Stürmer, J., Stefánsson, G., and Linares, J. I. Vico

Abstract

The two known planets in the planetary system of Teegarden's Star are among the most Earth-like exoplanets currently known. Revisiting this nearby planetary system with two planets in the habitable zone aims at a more complete census of planets around very low-mass stars. A significant number of new radial velocity measurements from CARMENES, ESPRESSO, MAROON-X, and HPF, as well as photometry from TESS motivated a deeper search for additional planets. We confirm and refine the orbital parameters of the two know planets Teegarden's Star b and c. We also report the detection of a third planet d with an orbital period of 26.13+-0.04 d and a minimum mass of 0.82+-0.17 M_Earth. A signal at 96 d is attributed to the stellar rotation period. The interpretation of a signal at 172 d remains open. The TESS data exclude transiting short-period planets down to about half an Earth radius. We compare the planetary system architecture of very low-mass stars. In the currently known configuration, the planetary system of Teegarden's star is dynamically quite different from that of TRAPPIST-1, which is more compact, but dynamically similar to others such as GJ 1002., Comment: Astronomy & Astrophysics, accepted; 21 pages, 18 figures

Published
2024

2. Characterising TOI-732 b and c: New insights into the M-dwarf radius and density valley

Author

Bonfanti, A., Brady, M., Wilson, T. G., Venturini, J., Egger, J. A., Brandeker, A., Sousa, S. G., Lendl, M., Simon, A. E., Queloz, D., Olofsson, G., Adibekyan, V., Alibert, Y., Fossati, L., Hooton, M. J., Kubyshkina, D., Luque, R., Murgas, F., Mustill, A. J., Santos, N. C., Van Grootel, V., Alonso, R., Asquier, J., Bandy, T., Bárczy, T., Navascues, D. Barrado, Barros, S. C. C., Baumjohann, W., Bean, J., Beck, M., Beck, T., Benz, W., Bergomi, M., Billot, N., Borsato, L., Broeg, C., Cameron, A. Collier, Csizmadia, Sz., Cubillos, P. E., Davies, M. B., Deleuil, M., Deline, A., Delrez, L., Demangeon, O. D. S., Demory, B. -O., Ehrenreich, D., Erikson, A., Fortier, A., Fridlund, M., Gandolfi, D., Gillon, M., Güdel, M., Günther, M. N., Heitzmann, A., Helling, Ch., Hoyer, S., Isaak, K. G., Kasper, D., Kiss, L. L., Lam, K. W. F., Laskar, J., Etangs, A. Lecavelier des, Magrin, D., Maxted, P. F. L., Mordasini, C., Nascimbeni, V., Ottensamer, R., Pagano, I., Pallé, E., Peter, G., Piotto, G., Pollacco, D., Ragazzoni, R., Rando, N., Rauer, H., Ribas, I., Scandariato, G., Ségransan, D., Seifahrt, A., Smith, A. M. S., Stalport, M., Stefánsson, G., Steinberger, M., Stürmer, J., Szabó, Gy. M., Thomas, N., Udry, S., Villaver, E., Walton, N. A., Westerdorff, K., Zingales, T., Bonfanti, A., Brady, M., Wilson, T. G., Venturini, J., Egger, J. A., Brandeker, A., Sousa, S. G., Lendl, M., Simon, A. E., Queloz, D., Olofsson, G., Adibekyan, V., Alibert, Y., Fossati, L., Hooton, M. J., Kubyshkina, D., Luque, R., Murgas, F., Mustill, A. J., Santos, N. C., Van Grootel, V., Alonso, R., Asquier, J., Bandy, T., Bárczy, T., Navascues, D. Barrado, Barros, S. C. C., Baumjohann, W., Bean, J., Beck, M., Beck, T., Benz, W., Bergomi, M., Billot, N., Borsato, L., Broeg, C., Cameron, A. Collier, Csizmadia, Sz., Cubillos, P. E., Davies, M. B., Deleuil, M., Deline, A., Delrez, L., Demangeon, O. D. S., Demory, B. -O., Ehrenreich, D., Erikson, A., Fortier, A., Fridlund, M., Gandolfi, D., Gillon, M., Güdel, M., Günther, M. N., Heitzmann, A., Helling, Ch., Hoyer, S., Isaak, K. G., Kasper, D., Kiss, L. L., Lam, K. W. F., Laskar, J., Etangs, A. Lecavelier des, Magrin, D., Maxted, P. F. L., Mordasini, C., Nascimbeni, V., Ottensamer, R., Pagano, I., Pallé, E., Peter, G., Piotto, G., Pollacco, D., Ragazzoni, R., Rando, N., Rauer, H., Ribas, I., Scandariato, G., Ségransan, D., Seifahrt, A., Smith, A. M. S., Stalport, M., Stefánsson, G., Steinberger, M., Stürmer, J., Szabó, Gy. M., Thomas, N., Udry, S., Villaver, E., Walton, N. A., Westerdorff, K., and Zingales, T.

Abstract

TOI-732 is an M dwarf hosting two transiting planets that are located on the two opposite sides of the radius valley. By doubling the number of available space-based observations and increasing the number of radial velocity (RV) measurements, we aim at refining the parameters of TOI-732 b and c. We also use the results to study the slope of the radius valley and the density valley for a well-characterised sample of M-dwarf exoplanets. We performed a global MCMC analysis by jointly modelling ground-based light curves and CHEOPS and TESS observations, along with RV time series both taken from the literature and obtained with the MAROON-X spectrograph. The slopes of the M-dwarf valleys were quantified via a Support Vector Machine (SVM) procedure. TOI-732 b is an ultrashort-period planet ($P\sim0.77$ d) with a radius $R_b=1.325_{-0.058}^{+0.057}$ $R_{\oplus}$ and a mass $M_b=2.46\pm0.19$ $M_{\oplus}$ (mean density $\rho_b=5.8_{-0.8}^{+1.0}$ g cm$^{-3}$), while the outer planet at $P\sim12.25$ d has $R_c=2.39_{-0.11}^{+0.10}$ $R_{\oplus}$, $M_c=8.04_{-0.48}^{+0.50}$ $M_{\oplus}$, and thus $\rho_c=3.24_{-0.43}^{+0.55}$ g cm$^{-3}$. Also taking into account our interior structure calculations, TOI-732 b is a super-Earth and TOI-732 c is a mini-Neptune. Following the SVM approach, we quantified $\mathrm{d}\log{R_{p,{\mathrm{valley}}}}/\mathrm{d}\log{P}=-0.065_{-0.013}^{+0.024}$, which is flatter than for Sun-like stars. In line with former analyses, we note that the radius valley for M-dwarf planets is more densely populated, and we further quantify the slope of the density valley as $\mathrm{d}\log{\hat{\rho}_{\mathrm{valley}}}/\mathrm{d}\log{P}=-0.02_{-0.04}^{+0.12}$. Compared to FGK stars, the weaker dependence of the position of the radius valley on the orbital period might indicate that the formation shapes the radius valley around M dwarfs more strongly than the evolution mechanisms., Comment: 28 pages (17 in the main text), 18 figures (9 in the main text), 11 tables (7 in the main text). Accepted for publication in A&A

Published
2023

3. TOI-1468: A system of two transiting planets, a super-Earth and a mini-Neptune, on opposite sides of the radius valley

Author

Chaturvedi, P., Bluhm, P., Nagel, E., Hatzes, A. P., Morello, G., Brady, M., Korth, J., Molaverdikhani, K., Kossakowski, D., Caballero, J. A., Guenther, E. W., Pallé, E., Espinoza, N., Seifahrt, A., Lodieu, N., Cifuentes, C., Furlan, E., Amado, P. J., Barclay, T., Bean, J., Béjar, V. J. S., Bergond, G., Boyle, A. W., Ciardi, D., Collins, K. A., Collins, K. I., Esparza-Borges, E., Fukui, A., Gnilka, C. L., Goeke, R., Guerra, P., Henning, Th., Herrero, E., Howell, S. B., Jeffers, S. V., Jenkins, J. M., Jensen, E. L. N., Kasper, D., Kodama, T., Latham, D. W., López-González, M. J., Luque, R., Montes, D., Morales, J. C., Mori, M., Murgas, F., Narita, N., Nowak, G., Parviainen, H., Passegger, V. M., Quirrenbach, A., Reffert, S., Reiners, A., Ribas, I., Ricker, G. R., Rodríguez, E., Rodríguez-López, C., Schlecker, M., Schwarz, R. P., Schweitzer, A., Seager, S., Stefánsson, G., Stockdale, C., Tal-Or, L., Twicken, J. D., Vanaverbeke, S., Wang, G., Watanabe, D., Winn, J. N., Zechmeister, M., Chaturvedi, P., Bluhm, P., Nagel, E., Hatzes, A. P., Morello, G., Brady, M., Korth, J., Molaverdikhani, K., Kossakowski, D., Caballero, J. A., Guenther, E. W., Pallé, E., Espinoza, N., Seifahrt, A., Lodieu, N., Cifuentes, C., Furlan, E., Amado, P. J., Barclay, T., Bean, J., Béjar, V. J. S., Bergond, G., Boyle, A. W., Ciardi, D., Collins, K. A., Collins, K. I., Esparza-Borges, E., Fukui, A., Gnilka, C. L., Goeke, R., Guerra, P., Henning, Th., Herrero, E., Howell, S. B., Jeffers, S. V., Jenkins, J. M., Jensen, E. L. N., Kasper, D., Kodama, T., Latham, D. W., López-González, M. J., Luque, R., Montes, D., Morales, J. C., Mori, M., Murgas, F., Narita, N., Nowak, G., Parviainen, H., Passegger, V. M., Quirrenbach, A., Reffert, S., Reiners, A., Ribas, I., Ricker, G. R., Rodríguez, E., Rodríguez-López, C., Schlecker, M., Schwarz, R. P., Schweitzer, A., Seager, S., Stefánsson, G., Stockdale, C., Tal-Or, L., Twicken, J. D., Vanaverbeke, S., Wang, G., Watanabe, D., Winn, J. N., and Zechmeister, M.

Abstract

We report the discovery and characterization of two small transiting planets orbiting the bright M3.0V star TOI-1468 (LSPM J0106+1913), whose transit signals were detected in the photometric time series in three sectors of the TESS mission. We confirm the e planetary nature of both of them using precise radial velocity measurements from the CARMENES and MAROON-X spectrographs, and supplement them with ground-based transit photometry. A joint analysis of all these data reveals that the shorter-period planet, TOI-1468 b ($P_{\rm b}$ = 1.88 d), has a planetary mass of $M_{\rm b} = 3.21\pm0.24$ $M_{\oplus}$ and a radius of $R_{\rm b} =1.280^{+0.038}_{-0.039} R_{\oplus}$, resulting in a density of $\rho_{\rm b} = 8.39^{+ 1.05}_{- 0.92}$ g cm$^{-3}$, which is consistent with a mostly rocky composition. For the outer planet, TOI-1468 c ($P_{\rm c} = 15.53$ d), we derive a mass of $M_{\rm c} = 6.64^{+ 0.67}_{- 0.68}$ $M_{\oplus}$, a radius of $R_{\rm c} = 2.06\pm0.04\,R_{\oplus}$, and a bulk density of $\rho_{c} = 2.00^{+ 0.21}_{- 0.19}$ g cm$^{-3}$, which corresponds to a rocky core composition with a H/He gas envelope. These planets are located on opposite sides of the radius valley, making our system an interesting discovery as there are only a handful of other systems with the same properties. This discovery can further help determine a more precise location of the radius valley for small planets around M dwarfs and, therefore, shed more light on planet formation and evolution scenarios., Comment: 26 pages, 15 figures

Published
2022
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4. On-sky commissioning of MAROON-X: A new precision radial velocity spectrograph for Gemini North

Author

Seifahrt, A., Bean, J. L., Stürmer, J., Kasper, D., Gers, L., Schwab, C., Zechmeister, M., Stefánsson, G., Montet, B., Santos, L. A. Dos, Peck, A., White, J., Tapia, E., Seifahrt, A., Bean, J. L., Stürmer, J., Kasper, D., Gers, L., Schwab, C., Zechmeister, M., Stefánsson, G., Montet, B., Santos, L. A. Dos, Peck, A., White, J., and Tapia, E.

Abstract

MAROON-X is a fiber-fed, red-optical, high precision radial velocity spectrograph recently commissioned at the Gemini North telescope on Mauna Kea, Hawai'i. With a resolving power of 85,000 and a wavelength coverage of 500-920 nm, it delivers radial velocity measurements for late K and M dwarfs with sub-50 cm s$^{-1}$ precision. MAROON-X is currently the only optical EPRV spectrograph on a 8m-class telescope in the northern hemisphere and the only EPRV instrument on a large telescope with full access by the entire US community. We report here on the results of the commissioning campaign in December 2019 and early science results., Comment: 21 pages, 14 figures

Published
2021
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5. On-sky commissioning of MAROON-X: A new precision radial velocity spectrograph for Gemini North

Author

Seifahrt, A., Bean, J. L., Stürmer, J., Kasper, D., Gers, L., Schwab, C., Zechmeister, M., Stefánsson, G., Montet, B., Santos, L. A. Dos, Peck, A., White, J., Tapia, E., Seifahrt, A., Bean, J. L., Stürmer, J., Kasper, D., Gers, L., Schwab, C., Zechmeister, M., Stefánsson, G., Montet, B., Santos, L. A. Dos, Peck, A., White, J., and Tapia, E.

Abstract

MAROON-X is a fiber-fed, red-optical, high precision radial velocity spectrograph recently commissioned at the Gemini North telescope on Mauna Kea, Hawai'i. With a resolving power of 85,000 and a wavelength coverage of 500-920 nm, it delivers radial velocity measurements for late K and M dwarfs with sub-50 cm s$^{-1}$ precision. MAROON-X is currently the only optical EPRV spectrograph on a 8m-class telescope in the northern hemisphere and the only EPRV instrument on a large telescope with full access by the entire US community. We report here on the results of the commissioning campaign in December 2019 and early science results., Comment: 21 pages, 14 figures

Published
2021
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6. Who joins the table? A critical overview of the co-creation approach for the implementation of an Ecosystem Approach to Fisheries Management

Author

Ballesteros, Marta, Chapela, R., Raakjær, J., Ramírez Monsalve, P., Hegland, T. J., Degnbol, P., Nielsen, K. N., Rahikainen, M., Baudron, A., Bartolino, Valerio, Colloca, Francesco, Ruiz Segura, Javier, Rincón, M.M., Pope, J., Agnarsson, Sveinn, Elvarsson, Bjarki Thor, Dickey-Collas, M., Stefánsson, G., Ballesteros, Marta, Chapela, R., Raakjær, J., Ramírez Monsalve, P., Hegland, T. J., Degnbol, P., Nielsen, K. N., Rahikainen, M., Baudron, A., Bartolino, Valerio, Colloca, Francesco, Ruiz Segura, Javier, Rincón, M.M., Pope, J., Agnarsson, Sveinn, Elvarsson, Bjarki Thor, Dickey-Collas, M., and Stefánsson, G.

Published
2017

7. Tools and processes to support scenario based planning in Ecosystem Based Fisheries Management: lessons from seven European case studies

Author

Nielsen, K. N., Aschan, M., Agnarsson, Sveinn, Ballesteros, Marta, Bartolino, Valerio, Baudron, A., Bauer, B., Colloca, Francesco, Daníelsdóttir, A. K., Elvarsson, Bjarki Thor, Fernandes, P. G., Hegland, T. J., Nenciu, M., Rahikainen, M., Ramírez Monsalve, P., Rincón, M.M., Ruiz Segura, Javier, Sirbu, G., Sinerchia, M., Raakjær, J., Stefánsson, G., Viðarsson, J. R., Nielsen, K. N., Aschan, M., Agnarsson, Sveinn, Ballesteros, Marta, Bartolino, Valerio, Baudron, A., Bauer, B., Colloca, Francesco, Daníelsdóttir, A. K., Elvarsson, Bjarki Thor, Fernandes, P. G., Hegland, T. J., Nenciu, M., Rahikainen, M., Ramírez Monsalve, P., Rincón, M.M., Ruiz Segura, Javier, Sirbu, G., Sinerchia, M., Raakjær, J., Stefánsson, G., and Viðarsson, J. R.

Published
2017

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