| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Columba |
| Right ascension | 06h 17m 20.7485s[1] |
| Declination | −38° 19′ 23.754″[1] |
| Apparent magnitude (V) | 11.10±0.08[2] |
| Characteristics | |
| Evolutionary stage | subgiant[1][2] |
| Spectral type | G8[3] |
| B−Vcolor index | 0.741±0.022[4] |
| J−Kcolor index | 0.425±0.032[4] |
| Astrometry | |
| Radial velocity (Rv) | −23.55±0.25[1] km/s |
| Proper motion (μ) | RA: −17.469mas/yr[1] Dec.: −27.292mas/yr[1] |
| Parallax (π) | 3.4609±0.0118 mas[1] |
| Distance | 942 ± 3 ly (288.9 ± 1.0 pc) |
| Details | |
| Mass | 1.10+0.06 −0.04[5] M☉ |
| Radius | 1.76+0.11 −0.08[5] R☉ |
| Luminosity | 2.76[1] L☉ |
| Surface gravity (log g) | 4.01±0.03[6] cgs |
| Temperature | 5715±60[6] K |
| Metallicity [Fe/H] | 0.08±0.07 dex[5] 0.28±0.05[6] dex |
| Rotational velocity (v sin i) | 2.8±0.5[5] km/s |
| Age | 8.3+1.3 −1.2[5] Gyr |
| Other designations | |
| Kosjenka,CD−38 2551,TOI-483,WASP-63,TYC 7612-556-1,GSC 07612-00556,2MASS J06172074-3819237[7] | |
| Database references | |
| SIMBAD | data |
WASP-63 orKosjenka, also known asCD-38 2551, is a singlestar with anexoplanetary companion in the southernconstellation ofColumba. It is too faint to be visible with the naked eye, having anapparent visual magnitude of 11.1.[2] The distance to this system is approximately 942light-years (289parsecs) based onparallax measurements, but it is drifting closer with aradial velocity of −24 km/s.
The designationWASP-63 indicates that this was the 63rd star found to have a planet by theWide Angle Search for Planets.
In August 2022, this planetary system was included among 20 systems to be named by the thirdNameExoWorlds project.[8] The approved names, proposed by a team fromCroatia, were announced in June 2023. WASP-63 is named Kosjenka and its planet is namedRegoč, after characters fromCroatian Tales of Long Ago byIvana Brlić-Mažuranić.[9]
This is aG-type star with astellar classification of G8;[3] theluminosity 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.[5] The stellar radius is enlarged for a G8 star,[3] and models suggest it hasevolved into asubgiant star.[1] It has 1.1 times the mass of the Sun and is spinning with aprojected rotational velocity of 3 km/s.[5]
In 2012 atransitinggas giant planet WASP-63b was detected on a tight, circular orbit.[3] Its equilibrium temperature is1536±37 K, and measured dayside temperature is1547±308 K.[10] The planet is similar toSaturn 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.[11]
| 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 |
