Chi Boötis
Star in the constellation Boötes
From Wikipedia, the free encyclopedia
Chi Boötis is a single,[11] white-hued star in the northern constellation Boötes, near the eastern constellation border with Corona Borealis. Its name is a Bayer designation that is Latinised from χ Boötis, and abbreviated Cho Boo or χ Boo. This star is faintly visible to the naked eye with an apparent visual magnitude of +5.3.[1] Based upon an annual parallax shift of 13.4 mas as seen from the Earth, it is located approximately 244 light-years (75 pc) from Earth. The star is moving closer to the Sun with a radial velocity of −16 km/s.[6]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Boötes[1] |
| Right ascension | 15h 14m 29.159s[2] |
| Declination | +29° 09′ 51.47″[2] |
| Apparent magnitude (V) | 5.28[1] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | A2 V[4] |
| U−B color index | +0.08[5] |
| B−V color index | +0.02[5] |
| Astrometry | |
| Radial velocity (Rv) | −16.0±0.8[6] km/s |
| Proper motion (μ) | RA: −69.512 mas/yr[2] Dec.: +28.662 mas/yr[2] |
| Parallax (π) | 13.3668±0.0584 mas[2] |
| Distance | 244 ± 1 ly (74.8 ± 0.3 pc) |
| Absolute magnitude (MV) | +0.84[1] |
| Details | |
| Mass | 2.09[7] M☉ |
| Radius | 2.24[8] R☉ |
| Luminosity | 36.8[9] L☉ |
| Surface gravity (log g) | 3.96±0.14[7] cgs |
| Temperature | 9,268±315[7] K |
| Rotational velocity (v sin i) | 84[7] km/s |
| Age | 340[7] Myr |
| Other designations | |
| χ Boo, 48 Boötis, BD+29°2640, FK5 3204, GC 20495, HD 135502, HIP 74596, HR 5676, SAO 83729[10] | |
| Database references | |
| SIMBAD | data |
This is an A-type main-sequence star with a stellar classification of A2 V,[4] which indicates it is generating energy via hydrogen fusion at its core. It is about 340[7] million years old with a projected rotational velocity of 84[7] km/s. The star has double the mass of the Sun,[7] 2.24 times the Sun's radius,[8] and is emitting 37[9] times the Sun's luminosity from its photosphere at an effective temperature of around 9,268 K.[7] It displays an infrared excess at an emission temperature of 65 K, indicating there is a circumstellar disk of dust orbiting the star at a distance of around 123 AU.[8]