HD 33564
Star in the constellation Camelopardalis
From Wikipedia, the free encyclopedia
HD 33564 is a single[7] star with an exoplanetary companion in the northern constellation of Camelopardalis. It has an apparent visual magnitude of 5.08,[1] which means it is a 5th magnitude star that is faintly visible to the naked eye. The system is located at a distance of 68 light years from the Sun based on parallax, and it is drifting closer with a radial velocity of −11 km/s.[2] It is a candidate member of the Ursa Major Moving Group.[8]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Camelopardalis[1] |
| Right ascension | 05h 22m 33.5306s[2] |
| Declination | +79° 13′ 52.143″[2] |
| Apparent magnitude (V) | 5.08[1] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | F7V[3] |
| U−B color index | −0.13 |
| B−V color index | 0.506±0.002[1] |
| Astrometry | |
| Radial velocity (Rv) | −11.09(13)[2] km/s |
| Proper motion (μ) | RA: −78.661(67) mas/yr[2] Dec.: 162.098(77) mas/yr[2] |
| Parallax (π) | 48.1098±0.0727 mas[2] |
| Distance | 67.8 ± 0.1 ly (20.79 ± 0.03 pc) |
| Absolute magnitude (MV) | 3.59[4] |
| Details | |
| Mass | 1.29[5] M☉ |
| Radius | 1.51+0.02 −0.06[6] R☉ |
| Luminosity | 3.428±0.017[6] L☉ |
| Surface gravity (log g) | 4.22[5] cgs |
| Temperature | 6,396+135 −36[6] K |
| Metallicity [Fe/H] | 0.14[5] dex |
| Rotational velocity (v sin i) | 14.3[5] km/s |
| Age | 1.80[5] Gyr |
| Other designations | |
| BD+79°169, GC 6455, GJ 196, HD 33564, HIP 25110, HR 1686, SAO 5496 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Description
This is an ordinary F-type main-sequence star with a stellar classification of F7V,[3] indicating that the star is hotter and more massive than the Sun, giving it a yellow-white hue. The star is about two[5] billion years old and is chromospherically quiet,[9] with a projected rotational velocity of 14.3 km/s. It has about 1.5[6] times the radius and 1.3[5] times the mass of the Sun. The star is radiating 3.4 times the luminosity of the Sun from its photosphere at an effective temperature of 6,396 K.[5]
Possible planetary system
In September 2005, a massive planet was found on an eccentric orbit about the star, based on a small sample of radial velocity variations measured by the ELODIE spectrograph. An infrared excess had been detected at a wavelength of 60 μm, suggesting the star may host a circumstellar disk. However, the existence of a disk is unlikely because the infrared radiation is coming from a background galaxy.[9]
The planet has not been confirmed by any subsequent study. Based on the limited data used to detect it and lack of follow-up observations, a 2025 study considered it a dubious planet detection.[10]: 49
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (disputed) | >9.1 MJ | 1.1 | 388 ± 3 | 0.34 ± 0.02 | — | — |