Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Boötes |
Right ascension | 14h 31m 49.78962s [1] |
Declination | +30° 22′ 17.1781″ [1] |
Apparent magnitude (V) | 3.59 [2] |
Characteristics | |
Spectral type | K4 III [3] |
U−B color index | +1.44 [2] |
B−V color index | +1.30 [2] |
R−I color index | 0.65 |
Astrometry | |
Radial velocity (Rv) | −13.57±0.19 [4] km/s |
Proper motion (μ) |
RA: –100.90
[1]
mas/
yr Dec.: +120.73 [1] mas/ yr |
Parallax (π) | 20.37 ± 0.18 mas [1] |
Distance | 160 ± 1
ly (49.1 ± 0.4 pc) |
Absolute magnitude (MV) | +0.27 [3] |
Details | |
Mass | 1.0–1.4 [5] M☉ |
Radius | 21.57±0.25 [5] R☉ |
Luminosity | 131.9±6.8 [5] L☉ |
Surface gravity (log g) | 1.85±0.05 [6] cgs |
Temperature | 4,298±56 [5] K |
Metallicity [Fe/H] | −0.19±0.10 [6] dex |
Age | 10.11±2.82 [6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Rho Boötis, Latinised from ρ Boötis, is a single, [8] orange-hued star in the northern constellation of Boötes. It is visible to the naked eye with an apparent visual magnitude of 3.59. [2] Based upon parallax measurements, it is located at a distance of approximately 160 light-years (49 parsecs) from Earth. It is moving toward the Sun with a radial velocity of −13.6 km/s. [4] There is an optical companion, a magnitude 11.5 star, located 34.7 arcseconds away along a position angle of 345° (as of 2013). [9]
This is an evolved K-type giant star, currently on the red-giant branch, with a stellar classification of K4 III [3] and an estimated age of 10 [6] billion years. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. [10] It has around 1.2 [5] times the mass of the Sun and has expanded to 22 [5] times the Sun's girth. The star is radiating 132 [5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of about 4,300 K. [5] Rho Boötis is classified as a RS Canum Venaticorum variable. [11] Koen and Eyer examined the Hipparcos data for this star, and found that it varied with a period of 5.214 days, and an amplitude of 0.0027 magnitudes. [12]
Rho Boötis is known by several different names, including ρ Boo, 25 Boötis, BD+31° 2628, FK5 534, HD 127665, HIP 71053, HR 5429, and SAO 64202. [13] In Chinese, 梗河 (Gěng Hé), meaning Celestial Lance, refers to an asterism consisting of ρ Boötis, ε Boötis and σ Boötis. [14] Consequently, the Chinese name for ρ Boötis itself is 梗河三 (Gěng Hé sān, English: the Third Star of Celestial Lance). [15]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Boötes |
Right ascension | 14h 31m 49.78962s [1] |
Declination | +30° 22′ 17.1781″ [1] |
Apparent magnitude (V) | 3.59 [2] |
Characteristics | |
Spectral type | K4 III [3] |
U−B color index | +1.44 [2] |
B−V color index | +1.30 [2] |
R−I color index | 0.65 |
Astrometry | |
Radial velocity (Rv) | −13.57±0.19 [4] km/s |
Proper motion (μ) |
RA: –100.90
[1]
mas/
yr Dec.: +120.73 [1] mas/ yr |
Parallax (π) | 20.37 ± 0.18 mas [1] |
Distance | 160 ± 1
ly (49.1 ± 0.4 pc) |
Absolute magnitude (MV) | +0.27 [3] |
Details | |
Mass | 1.0–1.4 [5] M☉ |
Radius | 21.57±0.25 [5] R☉ |
Luminosity | 131.9±6.8 [5] L☉ |
Surface gravity (log g) | 1.85±0.05 [6] cgs |
Temperature | 4,298±56 [5] K |
Metallicity [Fe/H] | −0.19±0.10 [6] dex |
Age | 10.11±2.82 [6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Rho Boötis, Latinised from ρ Boötis, is a single, [8] orange-hued star in the northern constellation of Boötes. It is visible to the naked eye with an apparent visual magnitude of 3.59. [2] Based upon parallax measurements, it is located at a distance of approximately 160 light-years (49 parsecs) from Earth. It is moving toward the Sun with a radial velocity of −13.6 km/s. [4] There is an optical companion, a magnitude 11.5 star, located 34.7 arcseconds away along a position angle of 345° (as of 2013). [9]
This is an evolved K-type giant star, currently on the red-giant branch, with a stellar classification of K4 III [3] and an estimated age of 10 [6] billion years. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. [10] It has around 1.2 [5] times the mass of the Sun and has expanded to 22 [5] times the Sun's girth. The star is radiating 132 [5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of about 4,300 K. [5] Rho Boötis is classified as a RS Canum Venaticorum variable. [11] Koen and Eyer examined the Hipparcos data for this star, and found that it varied with a period of 5.214 days, and an amplitude of 0.0027 magnitudes. [12]
Rho Boötis is known by several different names, including ρ Boo, 25 Boötis, BD+31° 2628, FK5 534, HD 127665, HIP 71053, HR 5429, and SAO 64202. [13] In Chinese, 梗河 (Gěng Hé), meaning Celestial Lance, refers to an asterism consisting of ρ Boötis, ε Boötis and σ Boötis. [14] Consequently, the Chinese name for ρ Boötis itself is 梗河三 (Gěng Hé sān, English: the Third Star of Celestial Lance). [15]