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NGTS discovery of a highly inflated Saturn-mass planet and a highly irradiated hot Jupiter
journal contribution
posted on 2024-05-14, 09:56 authored by F Bouchy, E Gillen, O Turner, S Gill, LD Nielsen, M Lendl, JI Vines, DR Alves, DR Anderson, DJ Armstrong, D Bayliss, JS Jenkins, JS Acton, C Belardi, EM Bryant, MR Burleigh, SL Casewell, JC Costes, A Chaushev, BF Cooke, Ph Eigmüller, A Erikson, MN Günther, MR Goad, N Grieves, J McCormac, M Moyano, L Raynard, AMS Smith, RH Tilbrook, S Udry, CA Watson, RG West, PJ WheatleyWe report the discovery of two new transiting giant exoplanets NGTS-26 b and NGTS-27 b by the Next Generation Transit Survey (NGTS). NGTS-26 b orbits around a G6-type main sequence star every 4.52 days. It has a mass of 0.29-0.06+0.07 MJup and a radius of 1.33-0.05+0.06 RJup making it a Saturn-mass planet with a highly inflated radius. NGTS-27 b orbits around a slightly evolved G3-type star every 3.37 days. It has a mass of 0.59-0.07+0.10 MJup and a radius of 1.40±0.04 RJup, making it a relatively standard hot Jupiter. The transits of these two planetary systems were re-observed and confirmed in photometry by the SAAO 1.0-m telescope, 1.2-m Euler Swiss telescope as well as the TESS spacecraft, and their masses were derived spectroscopically by the CORALIE, FEROS and HARPS spectrographs. Both giant exoplanets are highly irradiated by their host stars and present an anomalously inflated radius, especially NGTS-26 b which is one of the largest objects among peers of similar mass.
Funding
Funding for the TESS mission is provided by the NASA Explorer Program. This paper uses observations made at the South African Astronomical Observatory (SAAO). E.G. gratefully acknowledges support from the David and Claudia Harding Foundation in the form of a Winton Exoplanet Fellowship, and from the UK Science and Technology Facilities Council (STFC; project reference ST/W001047/1). J.S.J. gratefully acknowledges support by FONDECYT grant 1201371 and from the ANID BASAL projects ACE210002 and FB210003. This research was funded in part by the UKRI (Grants ST/X001121/1, EP/X027562/1). M.N.G. acknowledges support from the European Space Agency (ESA) as an ESA Research Fellow. M.L. acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. C.A.W. would like to acknowledge support from the STFC (grant number ST/X00094X/1).
Planets Through Time: Understanding the Evolution and Diversity of Planetary Systems
Science and Technology Facilities Council
Find out more...Warwick Astronomy & Astrophysics Consolidated Grant 2023-2026
Science and Technology Facilities Council
Find out more...INNATE Investigating the nature and origins of exoplanets in the Neptunian desert
UK Research and Innovation
Find out more...ST/X00094X/1
History
Author affiliation
College of Science & Engineering Physics & AstronomyVersion
- VoR (Version of Record)
Published in
Astronomy & AstrophysicsVolume
684Pagination
A201 - A201Publisher
EDP Sciencesissn
0004-6361eissn
1432-0746Copyright date
2024Available date
2024-05-14Publisher DOI
Language
enPublisher version
Deposited by
Dr Matthew BurleighDeposit date
2024-05-13Rights Retention Statement
- No
