J/A+A/666/A46       Two long-period transiting exoplanets    (Ulmer-Moll+, 2022)

Two long-period transiting exoplanets on eccentric orbits: NGTS-20 b (TOI-5152 b) and TOI-5153 b. Ulmer-Moll S., Lendl M., Gill S., Villanueva S., Hobson M.J., Bouchy F., Brahm R., Dragomir D., Grieves N., Mordasini C., Anderson D.R., Acton J.S., Bayliss D., Bieryla A., Burleigh M.R., Casewell S.L., Chaverot G., Eigmueller P., Feliz D., Gaudi S., Gillen E., Goad M.R., Gupta A.F., Guenther M.N., Henderson B.A., Henning T., Jenkins J.S., Jones M., Jordan A., Kendall A., Latham D.W., Mireles I., Moyano M., Nadol J., Osborn H.P., Pepper J., Pinto M.T., Psaridi A., Queloz D., Quinn S., Rojas F., Sarkis P., Schlecker M., Tilbrook R.H., Torres P., Trifonov T., Udry S., Vines J.I., West R., Wheatley P., Yao X., Zhao Y., Zhou G. <Astron. Astrophys. 666, A46 (2022)> =2022A&A...666A..46U 2022A&A...666A..46U (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, dwarfs ; Exoplanets ; Radial velocities ; Photometry ; Optical Keywords: planetary systems - planets and satellites: detection - planets and satellites: individual: NGTS 20/TOI-5152 - planets and satellites: individual: TOI-5153 - planets and satellites: gaseous planets - methods: data analysis Abstract: Long-period transiting planets provide the opportunity to better understand the formation and evolution of planetary systems. Their atmospheric properties remain largely unaltered by tidal or radiative effects of the host star, and their orbital arrangement reflects a different and less extreme migrational history compared to close-in objects. The sample of long-period exoplanets with well-determined masses and radii is still limited, but a growing number of long-period objects reveal themselves in the Transiting Exoplanet Survey Satellite (TESS) data. Our goal is to vet and confirm single-transit planet candidates detected in the TESS space-based photometric data through spectroscopic and photometric follow-up observations with ground-based instruments. We used high-resolution spectrographs to confirm the planetary nature of the transiting candidates and measure their masses. We also used the Next Generation Transit Survey (NGTS) to photometrically monitor the candidates in order to observe additional transits. Using a joint modeling of the light curves and radial velocities, we computed the orbital parameters of the system and were able to precisely measure the mass and radius of the transiting planets. We report the discovery of two massive, warm Jupiter-size planets, one transiting the F8-type star TOI-5153 and the other transiting the G1-type star NGTS-20 (=TOI-5152). From our spectroscopic analysis, both stars are metal-rich with a metallicity of 0.12 and 0.15. Follow-up radial velocity observations were carried out with CORALIE, CHIRON, FEROS, and HARPS. TOI-5153 hosts a 20.33 day period planet with a planetary mass of 3.26-0.17+0.18MJ, a radius of 1.06±0.04RJ, and an orbital eccentricity of 0.091-0.026+0.024. NGTS-20 b is a 2.98-0.15+0.16MJ planet with a radius of 1.07±0.04RJ on an eccentric 0.432±0.023 orbit with an orbital period of 54.19-days. Both planets are metal-enriched and their heavy element content is in line with the previously reported mass-metallicity relation for gas giants. Both warm Jupiters orbit moderately bright host stars, making these objects valuable targets for follow-up studies of the planetary atmosphere and measurement of the spin-orbit angle of the system. Description: Radial velocity measurements of NGTS-20 (=TOI-5152) and TOI-5153 taken with the high-resolution spectrographs CORALIE, CHIRON, FEROS, and HARPS. Tables include the date of observation, the radial velocity and its associated error, and the spectrograph used to measure the radial velocity. Objects: ----------------------------------------------------- RA (2000) DE Designation(s) ----------------------------------------------------- 06 06 09.67 -19 57 11.9 TOI-5153 = TIC 124029677 03 05 10.21 -21 56 01.1 TOI-5152 = TIC 257527578 ----------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 42 44 Radial velocities of TOI-5153 table2.dat 42 64 Radial velocities of NGTS-20 -------------------------------------------------------------------------------- See also: IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021) Byte-by-byte Description of file: table1.dat table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 16 F16.8 d BJD Barycentric Julian date 18- 26 F9.5 km/s RV Radial velocity (1) 28- 34 F7.5 km/s e_RV Radial velocity error 36- 42 A7 --- Inst Name of the instrument (CHIRON, CORALIE, FEROS or HARPS) -------------------------------------------------------------------------------- Note (1): In table2, relative radial velocity for CHIRON data. -------------------------------------------------------------------------------- Acknowledgements: Solene Ulmer-Moll, solene.ulmer-moll(at)unige.ch
(End) S. Ulmer-Moll [Geneva Ob., Switzerland], P. Vannier [CDS] 19-Aug-2022
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