HD 33564

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]

HD 33564

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]

Planetary system

In September 2005, a massive planet was found on an eccentric orbit about the star, based on 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 HD 33564 planetary system^[9]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	>9.1 MJ	1.1	388 ± 3	0.34 ± 0.02	—	—

See also

• List of extrasolar planets