TOI-2447 b / NGTS-29 b: a 69-day Saturn around a Solar analogue-Reference-Cited by-同舟云学术

TOI-2447 b / NGTS-29 b: a 69-day Saturn around a Solar analogue

Published:2024-07-05 Issue:2 Volume:532 Page:1444-1458
ISSN:0035-8711
Container-title:Monthly Notices of the Royal Astronomical Society
language:en
Short-container-title:

Author:

Gill Samuel¹²,Bayliss Daniel¹²^ORCID,Ulmer-Moll Solène³⁴,Wheatley Peter J¹²^ORCID,Brahm Rafael⁵⁶⁷,Anderson David R¹²^ORCID,Armstrong David¹²^ORCID,Apergis Ioannis¹²^ORCID,Alves Douglas R⁸⁹^ORCID,Burleigh Matthew R¹⁰,Butler R P¹¹,Bouchy François³,Battley Matthew P³,Bryant Edward M¹²^ORCID,Bieryla Allyson¹³^ORCID,Crane Jeffrey D¹⁴,Collins Karen A¹³,Casewell Sarah L¹⁰^ORCID,Carleo Ilaria¹⁵,Claringbold Alastair B¹²,Dalba Paul A¹⁶,Dragomir Diana¹⁷^ORCID,Eigmüller Philipp¹⁸,Eberhardt Jan¹⁹,Fausnaugh Michael²⁰,Günther Maximilian N²¹^ORCID,Grieves Nolan³^ORCID,Goad Michael R¹⁰,Gillen Edward²²²³^ORCID,Hagelberg Janis³^ORCID,Hobson Melissa⁶¹⁹,Hedges Christina²⁴,Henderson Beth A¹⁰^ORCID,Hawthorn Faith¹²^ORCID,Henning Thomas¹⁹,Jones Matías I²⁵,Jordán Andrés⁵⁶⁷,Jenkins James S⁹²⁶^ORCID,Kunimoto Michelle²⁰,Krenn Andreas F³²⁷,Kendall Alicia¹⁰,Lendl Monika³^ORCID,McCormac James¹²,Moyano Maximiliano²⁵^ORCID,Torres-Miranda Pascal⁶²⁸,Nielsen Louise D²⁹,Osborn Ares¹²^ORCID,Otegi Jon³,Osborn Hugh²⁰^ORCID,Quinn Samuel N¹³,Rodriguez Joseph E³⁰^ORCID,Ramsay Gavin³¹^ORCID,Schlecker Martin³²,Shectman Stephen A¹⁴,Seager Sara²⁰³³³⁴,Tilbrook Rosanna H¹⁰^ORCID,Trifonov Trifon¹⁹³⁵,Teske Johanna K¹¹,Udry Stephane³,Vines Jose I²⁵^ORCID,West Richard R¹²^ORCID,Wohler Bill³⁶,Winn Joshua N³⁷,Wang Sharon X³⁸,Zhou George³⁹,Zivave Tafadzwa¹²

Affiliation:

1. Department of Physics, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL , UK

2. Centre for Exoplanets and Habitability, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL , UK

3. Observatoire de Genève, Université de Genève , Chemin Pegasi 51, 1290 Versoix , Switzerland

4. Space Research and Planetary Sciences, Physics Institute, University of Bern , Gesellschaftsstrasse 6, 3012 Bern , Switzerland

5. Facultad de Ingeniera y Ciencias, Universidad Adolfo Ibáñez , Av. Diagonal las Torres 2640, Peñalolén, Santiago , Chile

6. Millennium Institute for Astrophysics , Chile

7. Data Observatory Foundation , Chile

8. Departamento de Astronomía, Universidad de Chile , Casilla 36-D, Santiago , Chile

9. Centro de Astrofísica y Tecnologías Afines (CATA) , Casilla 36-D, Santiago , Chile

10. School of Physics and Astronomy, University of Leicester , Leicester LE1 7RH , UK

11. Carnegie Earth and Planets Laboratory , 5241 Broad Branch Road NW, Washington, DC 20015 , USA

12. Mullard Space Science Laboratory, University College London, Holmbury St Mary , Dorking, Surrey, RH5 6NT , UK

13. Center for Astrophysics | Harvard

14. The Observatories of the Carnegie Institution for Science , 813 Santa Barbara St., Pasadena, CA 91101 , USA

15. Instituto de Astrofísica de Canarias (IAC) , 38205 La Laguna, Tenerife , Spain

16. Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064 , USA

17. Department of Physics and Astronomy, University of New Mexico , 210 Yale Blvd NE, Albuquerque, NM 87106 , USA

18. Institute of Planetary Research, German Aerospace Center , Rutherfordstrasse 2, 12489 Berlin , Germany

19. Max Planck Institute for Astronomy, Königstuhl 17 , 69117 - Heidelberg , Germany

20. Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, MA 02139 , USA

21. European Space Agency (ESA), European Space Research and Technology Centre (ESTEC) , Keplerlaan 1, 2201 AZ Noordwijk , The Netherlands

22. Astronomy Unit, Queen Mary University of London , Mile End Road, London E1 4NS , UK

23. Astrophysics Group, Cavendish Laboratory , J.J. Thomson Avenue, Cambridge CB3 0HE , UK

24. NASA Goddard Space Flight Center , 8800 Greenbelt Rd, Greenbelt, MD 20771 , USA

25. Instituto de Astronomía, Universidad Católica del Norte , Angamos 0610, 1270709, Antofagasta , Chile

26. Núcleo de Astronomía, Facultad de Ingeniería y Ciencias, Universidad Diego Portales , Av. Ejército 441, Santiago , Chile

27. Space Research Institute, Austrian Academy of Sciences , Schmiedlstraße 6, 8042 Graz , Austria

28. Instituto de Astrofísica, Facultad de Física , Pontificia Universidad Católica de. Chile

29. European Southern Observatory (ESO) , Karl-Schwarzschild-Str. 2, 85748 Garching bei München , Germany

30. Center for Data Intensive and Time Domain Astronomy, Department of Physics and Astronomy, Michigan State University , East Lansing, MI 48824 , USA

31. Armagh Observatory and Planetarium , College Hill, Armagh BT61 9DG , UK

32. Department of Astronomy/Steward Observatory, The University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721 , USA

33. Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA 02139 , USA

34. Department of Aeronautics and Astronautics , MIT, 77 Massachusetts Avenue, Cambridge, MA 02139 , USA

35. Department of Astronomy, Sofia University ‘St Kliment Ohridski’ , 5 James Bourchier Blvd, BG-1164 Sofia , Bulgari

36. NASA Ames Research Center , Moffett Field, CA 94035 , USA

37. Department of Astrophysical Sciences, 4 Ivy Lane, Princeton, University , Princeton, NJ 08540 US

38. Department of Astronomy, Tsinghua University , Beijing 100084 , China

39. Centre for Astrophysics, University of Southern Queensland , West Street, Toowoomba, QLD 4350 , Australia

Abstract

ABSTRACT Discovering transiting exoplanets with relatively long orbital periods (>10 d) is crucial to facilitate the study of cool exoplanet atmospheres (Teq < 700 K) and to understand exoplanet formation and inward migration further out than typical transiting exoplanets. In order to discover these longer period transiting exoplanets, long-term photometric, and radial velocity campaigns are required. We report the discovery of TOI-2447 b (=NGTS-29 b), a Saturn-mass transiting exoplanet orbiting a bright (T = 10.0) Solar-type star (Teff = 5730 K). TOI-2447 b was identified as a transiting exoplanet candidate from a single transit event of 1.3 per cent depth and 7.29 h duration in TESS Sector 31 and a prior transit event from 2017 in NGTS data. Four further transit events were observed with NGTS photometry which revealed an orbital period of P = 69.34 d. The transit events establish a radius for TOI-2447 b of $0.865 \pm 0.010\, \rm R_{\rm J}$, while radial velocity measurements give a mass of $0.386 \pm 0.025\, \rm M_{\rm J}$. The equilibrium temperature of the planet is 414 K, making it much cooler than the majority of TESS planet discoveries. We also detect a transit signal in NGTS data not caused by TOI-2447 b, along with transit timing variations and evidence for a ∼150 d signal in radial velocity measurements. It is likely that the system hosts additional planets, but further photometry and radial velocity campaigns will be needed to determine their parameters with confidence. TOI-2447 b/NGTS-29 b joins a small but growing population of cool giants that will provide crucial insights into giant planet composition and formation mechanisms.

Funder

STFC

Swiss National Science Foundation

FONDECYT

ANID

National Science Foundation

National Aeronautics and Space Administration

Publisher

Oxford University Press (OUP)

Link

https://academic.oup.com/mnras/article-pdf/532/2/1444/58754562/stae1256.pdf

Reference88 articles.