Delta Boötis

δ Boötis
Location of δ Boötis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Boötes
A
Right ascension 15h 15m 30.16282s
Declination +33° 18 53.3925
Apparent magnitude (V) 3.482
B
Right ascension 15h 15m 38.34898s
Declination +33° 19 15.3187
Apparent magnitude (V) 7.81
Characteristics
A
Spectral type G8 III
U−B color index +0.656
B−V color index +0.951
B
Spectral type G0 V
U−B color index +0.02
B−V color index +0.59
Astrometry
A
Radial velocity (Rv)−12.29±0.16 km/s
Proper motion (μ) RA: +84.383 mas/yr
Dec.: −111.591 mas/yr
Parallax (π)27.0746±0.1256 mas
Distance120.5 ± 0.6 ly
(36.9 ± 0.2 pc)
Absolute magnitude (MV)+0.700
B
Radial velocity (Rv)−11.83±0.18 km/s
Proper motion (μ) RA: +82.918 mas/yr
Dec.: −110.075 mas/yr
Parallax (π)27.1573 ± 0.0178 mas
Distance120.10 ± 0.08 ly
(36.82 ± 0.02 pc)
Absolute magnitude (MV)+4.96
Details
A
Mass1.5 M
Radius11.43±0.07 R
Luminosity58.1 L
Surface gravity (log g)2.38±0.09 cgs
Temperature4,810±30 K
Metallicity [Fe/H]−0.35±0.03 dex
Rotational velocity (v sin i)3.6 km/s
B
Mass0.98 M
Radius0.91±0.02 R
Luminosity0.87 L
Temperature5,812±67 K
Age3.09 Gyr
Other designations
STF 4027, ADS 9559, WDS 15155+3319
A: δ Boo, 49 Boötis, BD+33 2561, FK5 563, HD 135722, HIP 74666, HR 5681, SAO 64589
B: BD+33 2562, HIP 74674, SAO 64591
Database references
SIMBADA
B

Delta Boötis is a double star in the northern constellation of Boötes, forming the easternmost member of the constellation's kite-shaped asterism of brighter stars. Its name is a Bayer designation that is Latinized from δ Boötis, and abbreviated Delta Boo or δ Boo. Based upon parallax measurements, it is located at a distance of approximately 120.5 light-years (36.9 parsecs) from the Earth. The apparent visual magnitude of this star is 3.5, making it visible to the naked eye even during a Full Moon. The magnitude 7.81 companion can be viewed in binoculars or a small telescope.