NGTS discovery of a highly inflated Saturn-mass planet and a highly irradiated hot Jupiter. NGTS-26 b and NGTS-27 b
Abstract
We 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.
Full Tables 1 and 3 are also available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://138.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/684/A201- Publication:
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Astronomy and Astrophysics
- Pub Date:
- April 2024
- DOI:
- 10.1051/0004-6361/202347162
- Bibcode:
- 2024A&A...684A.201B
- Keywords:
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- techniques: photometric;
- planets and satellites: detection;
- planets and satellites: individual: NGTS-26 b;
- planets and satellites: individual: NGTS-27 b;
- planetary systems