7 Boötis
Star in the constellation Boötes
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7 Boötis is a single[5] star in the northern constellation of Boötes,[4] located 590 light-years away from the Sun.[1] It is barely visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.71.[2] 7 Boötis is moving closer to the Earth with a heliocentric radial velocity of −11 km/s.[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 13h 53m 12.93033s[1] |
| Declination | +17° 55′ 58.3282″[1] |
| Apparent magnitude (V) | 5.71[2] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | G5 III[2] |
| B−V color index | 0.845[3] |
| Astrometry | |
| Radial velocity (Rv) | −11.00±0.18[1] km/s |
| Proper motion (μ) | RA: −34.842[1] mas/yr Dec.: +5.092[1] mas/yr |
| Parallax (π) | 5.5236±0.0776 mas[1] |
| Distance | 590 ± 8 ly (181 ± 3 pc) |
| Details[2] | |
| Mass | 4.0±0.7 M☉ |
| Radius | 19.0 R☉ |
| Luminosity | 229 L☉ |
| Temperature | 4,600 K |
| Metallicity [Fe/H] | +0.08 dex |
| Rotational velocity (v sin i) | 14.5 km/s |
| Other designations | |
| 7 Boo, BD+18°2795, HD 121107, HIP 67787, HR 5225, SAO 100751[4] | |
| Database references | |
| SIMBAD | data |
This is an evolved subgiant star with a stellar classification of G5 III, currently at the end of the Hertzsprung gap. It has a weak level of magnetic activity but a fairly strong X-ray luminosity of 3.72×1020 erg s−1. The rotation rate is moderate, with a projected rotational velocity of 14.5 km/s. It has four times the mass of the Sun and has expanded to 19 times the Sun's radius. The star is radiating 229 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,600 K.[2]