Nu1 Boötis
Orange-hued star in the constellation Boötes
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Nu1 Boötis is an orange-hued star in the northern constellation of Boötes. Its name is a Bayer designation that is Latinized from ν1 Boötis, and abbreviated Nu1 Boo or ν1 Boo. This star has an apparent visual magnitude of +5.02,[2] which is bright enough to be faintly visible to the naked eye. Based upon an annual parallax shift of 3.35 mas as seen from Earth,[1] it is located approximately 970 light years distant from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction of 0.13 due to interstellar dust.[10] It is drifting closer to the Sun with a radial velocity of −11.1 km/s.[4]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Boötes |
| Right ascension | 15h 30m 55.75060s[1] |
| Declination | +40° 49′ 58.9743″[1] |
| Apparent magnitude (V) | +5.02[2] |
| Characteristics | |
| Spectral type | K4.5 IIIb Ba0.4[3] |
| U−B color index | +1.91[2] |
| B−V color index | +1.59[2] |
| Astrometry | |
| Radial velocity (Rv) | −11.12±0.16[4] km/s |
| Proper motion (μ) | RA: +10.563 mas/yr[1] Dec.: −8.385 mas/yr[1] |
| Parallax (π) | 3.3492±0.077 mas[1] |
| Distance | 970 ± 20 ly (299 ± 7 pc) |
| Absolute magnitude (MV) | −2.22[5] |
| Details | |
| Radius | 99.8±4.26[6] R☉ |
| Luminosity | 2,054±163[6] L☉ |
| Surface gravity (log g) | 1.15±0.17[7] cgs |
| Temperature | 3,917±27[7] K |
| Metallicity [Fe/H] | +0.00±0.06[7] dex |
| Rotational velocity (v sin i) | 4.2[8] km/s |
| Other designations | |
| ν1 Boo, ψ Her, 52 Boötis, BD+41°2609, FK5 573, GC 20866, HD 138481, HIP 75973, HR 5763, SAO 45580, PPM 54790[9] | |
| Database references | |
| SIMBAD | data |
This is an evolved K-type giant star with a stellar classification of K4.5 IIIb Ba0.4.[3] The 'Ba0.4' suffix notation indicates this is a weak barium star,[11] which means that the stellar atmosphere has been enhanced by s-process elements most likely provided by what is now an orbiting white dwarf companion.[12] The giant component has 99.8 times the radius of the Sun. It is radiating 2,054[6] times the Sun's luminosity from its enlarged photosphere at an effective temperature of about 3,917 K.[7]
Ptolemy considered Nu Boötis to be shared by Hercules, and Bayer assigned it a designation in both constellations: Nu Boötis (ν Boo) and Psi Herculis (ψ Her). When the modern constellation boundaries were fixed in 1930, the latter designation dropped from use.[13]