47 Boötis
Binary star system in the constellation Boötes
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47 Boötis is a binary star[9] system in the northern constellation of Boötes,[8] located 261 light years away from the Sun.[1] It has the Bayer designation k Boötis; 47 Boötis is the Flamsteed designation.[8] The system is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.58.[2] It is moving closer to the Earth with a heliocentric radial velocity of −13 km/s.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 15h 05m 25.83464s[1] |
| Declination | +48° 09′ 03.4943″[1] |
| Apparent magnitude (V) | 5.581[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | A0 Vs[4] |
| B−V color index | −0.005±0.003[5] |
| Variable type | suspected[6] |
| Astrometry | |
| Radial velocity (Rv) | −12.63±0.73[2] km/s |
| Proper motion (μ) | RA: −65.912[1] mas/yr Dec.: +28.641[1] mas/yr |
| Parallax (π) | 12.4980±0.0766 mas[1] |
| Distance | 261 ± 2 ly (80.0 ± 0.5 pc) |
| Absolute magnitude (MV) | 0.97[5] |
| Details | |
| 47 Boo A | |
| Mass | 2.46±0.02[3] M☉ |
| Radius | 1.8[7] R☉ |
| Luminosity | 45.7+2.2 −2.0[2] L☉ |
| Surface gravity (log g) | 4.32[2] cgs |
| Temperature | 10,130[2] K |
| Rotational velocity (v sin i) | 54.8±1.6[2] km/s |
| Other designations | |
| k Boo, 47 Boo, NSV 6934, BD+48°2262, FK5 1395, GC 20308, HD 133962, HIP 73841, HR 5627, SAO 45370, ADS 9500, CCDM 15054+4809[8] | |
| Database references | |
| SIMBAD | data |
The primary member of the system, designated component A, is an A-type main-sequence star with a stellar classification of A0 Vs.[4] The 's' indicates sharp lines as it has a moderate rotation rate with a projected rotational velocity of 55 km/s.[2] It is a suspected variable star of unknown type.[10] The star has 2.46[3] times the mass of the Sun and is radiating 46[2] times the Sun's luminosity from its photosphere at an effective temperature of 10,130 K.[2]
The companion, component B, is a magnitude 13.3 star located at an angular separation of 6.2 arcseconds away from the primary.[9]