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Author Jones, MI.; Wittenmyer, R.; Aguilera-Gomez, C.; Soto, MG.; Torres, P.; Trifonov, T.; Jenkins, JS.; Zapata, A.; Sarkis, P.; Zakhozhay, O.; Brahm, R.; Ramirez, R.; Santana, F.; Vines, JI.; Diaz, MR.; Vuckovic, M.; Pantoja, B.
Title Four Jovian planets around low-luminosity giant stars observed by the EXPRESS and PPPS Type
Year 2021 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume 646 Issue Pages A131
Keywords asteroseismology; techniques: radial velocities; planets and satellites: detection; planets and satellites: formation
Abstract We report the discovery of planetary companions orbiting four low-luminosity giant stars with M-star between 1.04 and 1.39 M-circle dot. All four host stars have been independently observed by the EXoPlanets aRound Evolved StarS (EXPRESS) program and the Pan-Pacific Planet Search (PPPS). The companion signals were revealed by multi-epoch precision radial velocities obtained in nearly a decade. The planetary companions exhibit orbital periods between similar to 1.2 and 7.1 yr, minimum masses of m(p)sin i similar to 1.8-3.7 M-J, and eccentricities between 0.08 and 0.42. With these four new systems, we have detected planetary companions to 11 out of the 37 giant stars that are common targets in the EXPRESS and PPPS. After excluding four compact binaries from the common sample, we obtained a fraction of giant planets (m(p) greater than or similar to 1- 2 M-J) orbiting within 5 AU from their parent star of f = 33.3(-7.1)(+9.0)%. This fraction is slightly higher than but consistent at the 1 sigma level with previous results obtained by different radial velocity surveys. Finally, this value is substantially higher than the fraction predicted by planet formation models of gas giants around stars more massive than the Sun.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6361 ISBN Medium
Area Expedition Conference
Notes WOS:000621398400001 Approved
Call Number (up) UAI @ alexi.delcanto @ Serial 1349
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Author Grieves, N.; Nielsen, LD.; Vines, JI.; Bryant, EM.; Gill, S.; Bouchy, F.; Lendl, M.; Bayliss, D.; Eigmueller, P.; Segransan, D.; Acton, JS.; Anderson, DR.; Burleigh, MR.; Casewell, SL.; Chaushev, A.; Cooke, BF.; Gillen, E.; Goad, MR.; Gunther, MN.; Henderson, BA.; Hogan, A.; Jenkins, JS.; Alves, DR.; Jordan, A.; McCormac, J.; Moyano, M.; Queloz, D.; Raynard, L.; Seidel, JV.; Smith, AMS.; Tilbrook, RH.; Udry, S.; West, RG.; Wheatley, PJ.
Title NGTS-13b: a hot 4.8 Jupiter-mass planet transiting a subgiant star Type
Year 2021 Publication Astronomy & Astrophysics Abbreviated Journal Astron. Astrophys.
Volume 647 Issue Pages A180
Keywords planets and satellites: detection; planets and satellites: individual: NGTS-13b; techniques: photometric; techniques: radial velocities
Abstract We report the discovery of the massive hot Jupiter NGTS-13b by the Next Generation Transit Survey (NGTS). The V = 12.7 host star is likely in the subgiant evolutionary phase with logg(*) = 4.04 +/- 0.05, T-eff = 5819 +/- 73 K, M-* = 1.30(-0.18)(+0.11) M-circle dot, and R-* = 1.79 +/- 0.06 R-circle dot. The NGTS detected a transiting planet with a period of P = 4.12 days around the star, which was later validated with the Transiting Exoplanet Survey Satellite (TESS; TIC 454069765). We confirm the planet using radial velocities from the CORALIE spectrograph. Using NGTS and TESS full-frame image photometry combined with CORALIE radial velocities, we determine NGTS-13b to have a radius of R-P = 1.142 +/- 0.046 R-Jup, a mass of M-P = 4.84 +/- 0.44 M-Jup, and an eccentricity of e = 0.086 +/- 0.034. Previous studies have suggested that similar to 4 M-Jup may be the border separating two formation scenarios (e.g., core accretion and disk instability) and that massive giant planets share similar formation mechanisms as lower-mass brown dwarfs. NGTS-13b is just above 4 M-Jup, making it an important addition to the statistical sample needed to understand the differences between various classes of substellar companions. The high metallicity of NGTS-13, [Fe/H] = 0.25 +/- 0.17, does not support previous suggestions that massive giants are found preferentially around lower metallicity host stars, but NGTS-13b does support findings that more massive and evolved hosts may have a higher occurrence of close-in massive planets than lower-mass unevolved stars.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area 0004-6361 Expedition Conference
Notes WOS:000636753900003 Approved
Call Number (up) UAI @ alexi.delcanto @ Serial 1372
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