TOI-4603 b is a gas giant exoplanet orbiting HD 245134, a F-type subgiant star located 731 light-years away, in the constellation of Taurus.[3][note 1] It orbits its host star at a distance of 0.0888 astronomical units (13,280,000 km), completing one orbit every 7 days around it.[2] With a density of 14.1 g/cm3 (about 2.5 times that of Earth), it is one of the densest exoplanets known.[2] The planet is just 4% larger than Jupiter, but is 12.9 times more massive, being located in the mass limit between planets and brown dwarfs.[2]
| Discovery | |
|---|---|
| Discovered by | Khandelwal et al.[1] |
| Discovery site |  India |
| Discovery date | 2023 |
| Transit | |
| Orbital characteristics | |
| 0.0888±0.001 AU[2] | |
| Eccentricity | 0.325±0.02[2] |
| 7.246[2] d | |
| Inclination | 80.21°[2] |
| Star | HD 245134 (TOI-4603) |
| Physical characteristics | |
| 1.042+0.035 −0.038 RJ[2] | |
| Mass | 12.89+0.57 −0.58 MJ[2] |
Mean density | 14.1+1.6 −1.7 g/cm3[2] |
| Temperature | 1,677±24 K (1404 °C)[2] |
Physical characteristics
editTOI-4603 b is similar to the planet Jupiter in size, being only 4% larger.[2] Radial velocity measurements calculated the planet's mass to be 12.89+0.58
−0.57 MJ[4] meaning that the object is close to the mass limit between planets and brown dwarfs, which is usually set at 13 MJ.[2] Its equilibrium temperature is calculated at 1,677 K (1,404 °C).[2]
High density
editCombining the radius and mass, the density of TOI-4603 b is calculated to be 14.1+1.6
−1.7 g/cm³, about 2.5 times greater than Earth's,[note 2] making it one of the densest exoplanets known to date, and one of the most massive and dense transting exoplanets known.[2]
Orbital characteristics
editTOI-4603 b orbits its star at a distance of 0.0888 astronomical units (13,280,000 km), and completes one orbit every 7 days and 6 hours.[2] The orbit of TOI-4603 b is very elliptical, having a orbital eccentricity of 0.325, which indicates that the planet is undergoing tidal migration due to an gravitational interaction with another planet.[2] Kervella et al. (2019) found that a brown dwarf with a mass of 20.5 MJ is orbiting the system at a distance of around 1.8 AU, which may be influencing TOI-4603 b's orbit.[2]
A similar object is a planet called HATS-70b. It is less dense than TOI-4603 b, but similarly close to its star, and also shows signs of orbital migration.[4]
Discovery
editNASA's Transiting Exoplanet Survey Satellite observed the host star TOI-4603 between September 16, 2021, and December 2, 2021.[2] Afterwards, the group of astronomers led by Akanksha Khandelwal of the Physical Research Laboratory (PRL) in India, reported that a transit signal had been identified in the light curve of the star. Radial velocity measurements taken with the PARAS and TRES[note 3] spectrographs confirmed the transit signal to be an exoplanet orbiting the star.[6]
It was the third exoplanet discovered by Indian astronomers, using the PARAS spectrograph and the PRL 1.2 m telescope.[7] The discovery was announced in 2023.[8]
Host star
edit| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus[note 1] |
| Right ascension | 05h 35m 27.82281s[9] |
| Declination | +21° 17′ 39.6246″[9] |
| Apparent magnitude (V) | 9.2[2] |
| Characteristics | |
| Evolutionary stage | Subgiant |
| Spectral type | F |
| Astrometry | |
| Radial velocity (Rv) | -3.29[10] km/s |
| Proper motion (μ) | RA: +0.102 mas/yr[9] Dec.: −22.866 mas/yr[9] |
| Parallax (π) | 4.4613 ± 0.0195 mas[9] |
| Distance | 735.596+8.098 −7.928 ly (225.643+2.484 −2.432 pc)[1] |
| Details[2] | |
| Mass | 1.765±0.061 M☉ |
| Radius | 2.738+0.061 −0.050 R☉ |
| Luminosity | 10.4 L☉ |
| Surface gravity (log g) | 3.94±0.1 cgs |
| Temperature | 6,264+95 −94 K |
| Metallicity [Fe/H] | 0.342+0.039 −0.040 dex |
| Rotational velocity (v sin i) | 23.18±0.37 km/s |
| Age | 1.64+0.30 −0.24 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 245134 (TOI-4603) is a F-type subgiant located 736 light-years away in the constellation of Taurus.[1] [note 1] It is well suited for the study of the Rossiter–McLaughlin effect and helpful for measuring the projected stellar obliquity of planets.[2] The star has an apparent magnitude of 9.2, being too faint to be seen with the naked eye.[1] It is a metal-rich star, with abundance of iron 2.2 times greater than that of the Sun.[2]
Orbital companions
editHD 245134 is orbited by an exoplanet (TOI-4603 b), and by a 20.5 MJ brown dwarf star at a distance of 1.8 AU from the star.[2]
Notes
editReferences
edit- ^ a b c d "TOI-4603 Overview". NASA Exoplanet Archive. Retrieved 2023-12-03.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x Khandelwal, Akanksha; Sharma, Rishikesh; Chakraborty, Abhijit; Chaturvedi, Priyanka; Ulmer-Moll, Solène; Ciardi, David R.; Boyle, Andrew W.; Baliwal, Sanjay; Bieryla, Allyson; Latham, David W.; Prasad, Neelam J. S. S. V.; Nayak, Ashirbad; Lendl, Monika; Mordasini, Christoph (2023-04-01). "Discovery of a massive giant planet with extreme density around the sub-giant star TOI-4603". Astronomy & Astrophysics. 672: L7. arXiv:2303.11841. doi:10.1051/0004-6361/202245608. ISSN 0004-6361.
- ^ "⬤ Exoplanet TOI 4603 b". Stellar Catalog. Retrieved 2023-12-03.
- ^ a b Starr, Michelle (2023-03-29). "Jupiter-Sized 'Cannonball' Planet Discovered With a Density Greater Than Lead". ScienceAlert. Retrieved 2023-12-04.
- ^ "Facts About Earth - NASA Science". science.nasa.gov. Retrieved 2023-12-04.
- ^ Nowakowski, Tomasz; Phys.org. "Massive giant exoplanet discovered with TESS". phys.org. Retrieved 2023-12-04.
- ^ "India discovers TOI 4603b Exoplanet - Civilsdaily". 2023-05-31. Retrieved 2023-12-03.
- ^ Martin, Pierre-Yves (2023). "Planet TOI-4603 b". Extrasolar Planets Encyclopaedia. Retrieved 2023-12-03.
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b "HD 245134". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-12-04.