22 Boötis
Star in the constellation Boötes
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22 Boötis is a single[6] star in the northern constellation of Boötes,[5] located 319 light years away from the Sun.[2] It has the Bayer designation f Boötis; 22 Boötis is the Flamsteed designation.[5] This object is visible to the naked eye as a dim, white-hued star with an apparent visual magnitude of 5.40.[1] It is moving closer to the Earth with a heliocentric radial velocity of −27 km/s.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes[1] |
| Right ascension | 14h 26m 27.36529s[2] |
| Declination | +19° 13′ 36.8470″[2] |
| Apparent magnitude (V) | 5.40[1] |
| Characteristics | |
| Spectral type | kA7hA8mF2(III)((Sr II))[3] |
| B−V color index | 0.231±0.006[1] |
| Astrometry | |
| Radial velocity (Rv) | −27.4±0.5[1] km/s |
| Proper motion (μ) | RA: −70.131[2] mas/yr Dec.: +26.084[2] mas/yr |
| Parallax (π) | 10.2279±0.1491 mas[2] |
| Distance | 319 ± 5 ly (98 ± 1 pc) |
| Absolute magnitude (MV) | 0.65[1] |
| Details | |
| Mass | 1.99±0.02[4] M☉ |
| Radius | 4.03+0.23 −0.26[2] R☉ |
| Luminosity | 52.43±0.89[2] L☉ |
| Surface gravity (log g) | 3.13±0.52[4] cgs |
| Temperature | 7,528+277 −207[2] K |
| Metallicity [Fe/H] | +0.36±0.04[1] dex |
| Rotational velocity (v sin i) | 37.74±2.12[1] km/s |
| Other designations | |
| f Boo, 22 Boo, BD+19°2810, FK5 1378, GC 19480, HD 126661, HIP 70602, HR 5405, SAO 101025[5] | |
| Database references | |
| SIMBAD | data |
This is an Am star[7] with a stellar classification of kA7 hA8 mF2 (III) ((Sr II)),[3] showing the calcium K line of an A7 star, the hydrogen lines of an A8 star, and the metal lines of an F2 star. It has the luminosity class of a giant star and does not appear to be variable.[7] The star has twice[4] the mass of the Sun and four[2] times the Sun's radius. It is spinning with a projected rotational velocity of 38[1] km/s. 22 Boötis is radiating 52[2] times the Sun's luminosity from its photosphere at an effective temperature of 7,528 K.[2]