| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Columba1 |
| Right ascension | 06h 17m 20.7485s2 |
| Declination | −38° 19′ 23.754″2 |
| Apparent magnitude (V) | 11.10±0.083 |
| Characteristics | |
| Evolutionary stage | subgiant23 |
| Spectral type | G84 |
| B−V color index | 0.741±0.0225 |
| J−K color index | 0.425±0.0325 |
| Astrometry | |
| Radial velocity (Rv) | −23.55±0.252 km/s |
| Proper motion (μ) | RA: −17.469 mas/yr2 Dec.: −27.292 mas/yr2 |
| Parallax (π) | 3.4609±0.0118 mas2 |
| Distance | 942 ± 3 ly (288.9 ± 1.0 pc) |
| Details | |
| Mass | 1.10+0.06 −0.046 M☉ |
| Radius | 1.76+0.11 −0.086 R☉ |
| Luminosity | 2.762 L☉ |
| Surface gravity (log g) | 4.01±0.037 cgs |
| Temperature | 5,715±607 K |
| Metallicity [Fe/H] | 0.08±0.07 dex6 0.28±0.057 dex |
| Rotational velocity (v sin i) | 2.8±0.56 km/s |
| Age | 8.3+1.3 −1.26 Gyr |
| Other designations | |
| Kosjenka, CD−38 2551, TOI-483, WASP-63, TYC 7612-556-1, GSC 07612-00556, 2MASS J06172074-38192378 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
WASP-63, also named Kosjenka, is a single star with an exoplanetary companion in the southern constellation of Columba. It is too faint to be visible with the naked eye, having an apparent visual magnitude of 11.1.3 The distance to this system is approximately 942 light-years (289 parsecs) based on parallax measurements, but it is drifting closer with a radial velocity of −24 km/s.
Nomenclature
The designation WASP-63 indicates that this was the 63rd star found to have a planet by the Wide Angle Search for Planets. It is also known as CD-38 2551 from the Durchmusterung catalog.8
In the 2019 NameExoWorlds campaign, this system was assigned to Malawi910 but did not get named at that time. It was then included among 20 systems to be named by the following NameExoWorlds campaign in August 2022.11 The approved names, proposed by a team from Croatia, were announced in June 2023. WASP-63 is named Kosjenka and its planet is named Regoč, after characters from Croatian Tales of Long Ago by Ivana Brlić-Mažuranić.12
Stellar properties
This is a G-type star with a stellar classification of G8;4 the luminosity class is currently unknown. The star is much older than the Sun at approximately 8.3+1.3
−1.2 billion years. WASP-63 is slightly enriched in heavy elements, having 120% of the solar abundance of iron.6 The stellar radius is enlarged for a G8 star,4 and models suggest it has evolved into a subgiant.2 It has 1.1 times the mass of the Sun and is spinning with a projected rotational velocity of 3 km/s.6
Planetary system
In 2012 a transiting gas giant planet WASP-63b was detected on a tight, circular orbit.4 Its equilibrium temperature is 1,536±37 K, and measured dayside temperature is 1,547±308 K.13 The planet is similar to Saturn in mass but is highly inflated due to proximity to the parent star. The planetary atmosphere contains water and likely has a high cloud deck of indeterminate composition.14
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b / Regoč | 0.339±0.03 MJ | 0.05417+0.00067 −0.00089 |
4.3780900±0.000006 | 0.026+0.040 −0.029 |
87.8±1.3 | 1.33±0.24 RJ |
References
References
- Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
- 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.
- Santos, N. C.; et al. (August 2013), "SWEET-Cat: A catalogue of parameters for Stars With ExoplanETs. I. New atmospheric parameters and masses for 48 stars with planets", Astronomy & Astrophysics, 556: 11, arXiv:1307.0354, Bibcode:2013A&A...556A.150S, doi:10.1051/0004-6361/201321286, S2CID 55237847, A150.
- Hellier, Coel; et al. (2012), "Seven transiting hot-Jupiters from WASP-South, Euler and TRAPPIST: WASP-47b, WASP-55b, WASP-61b, WASP-62b, WASP-63b, WASP-66b & WASP-67b", Monthly Notices of the Royal Astronomical Society, 426 (1): 739–750, arXiv:1204.5095, Bibcode:2012MNRAS.426..739H, doi:10.1111/j.1365-2966.2012.21780.x, S2CID 54713354
- Brown, D. J. A. (2014), "Discrepancies between isochrone fitting and gyrochronology for exoplanet host stars?", Monthly Notices of the Royal Astronomical Society, 442 (2): 1844–1862, arXiv:1406.4402, Bibcode:2014MNRAS.442.1844B, doi:10.1093/mnras/stu950, S2CID 56052792.
- Bonomo, A. S.; et al. (2017), "The GAPS Programme with HARPS-N at TNG", Astronomy & Astrophysics, 602: A107, arXiv:1704.00373, Bibcode:2017A&A...602A.107B, doi:10.1051/0004-6361/201629882, S2CID 118923163
- Stassun, Keivan G.; Collins, Karen A.; Gaudi, B. Scott (2016), "Accurate Empirical Radii and Masses of Planets and Their Host Stars with Gaia Parallaxes", The Astronomical Journal, 153 (3): 136, arXiv:1609.04389, Bibcode:2017AJ....153..136S, doi:10.3847/1538-3881/aa5df3, S2CID 119219062
- "CD-38 2551". SIMBAD. Centre de données astronomiques de Strasbourg.
- "Naming". WASP Planets. 24 June 2019. Retrieved 24 June 2025.
- "Malawi". NameExoWorlds. IAU. Archived from the original on 20 December 2019.
- "List of ExoWorlds 2022". nameexoworlds.iau.org. IAU. 8 August 2022. Retrieved 27 August 2022.
- "2022 Approved Names". NameExoWorlds. IAU. Retrieved 7 June 2023.
- Garhart, Emily; et al. (2020), "Statistical Characterization of Hot Jupiter Atmospheres Using Spitzer's Secondary Eclipses", The Astronomical Journal, 159 (4): 137, arXiv:1901.07040, Bibcode:2020AJ....159..137G, doi:10.3847/1538-3881/ab6cff, S2CID 119209434
- Kilpatrick, Brian M.; et al. (2017), "Community Targets of JWST's Early Release Science Program: Evaluation of WASP-63b", The Astronomical Journal, 156 (3): 103, arXiv:1704.07421, Bibcode:2018AJ....156..103K, doi:10.3847/1538-3881/aacea7, S2CID 52831173