Mu Boötis

μ^1,2 Boötis

Observation data Epoch J2000      Equinox J2000
Constellation	Boötes
Right ascension	15h 24m 29.4278s
Declination	+37° 22′ 37.8″
Apparent magnitude (V)	4.397 / 6.5
Characteristics
Spectral type	F0V / G1V
U−B color index	0.07 / 0.13
B−V color index	0.31 / 0.59
R−I color index	0.15 /
Variable type	Variable star
Astrometry
Radial velocity (Rv)	-12.5 km/s
Proper motion (μ)	RA: -147.68 mas/yr Dec.: 84.69 mas/yr
Parallax (π)	26.96 ± 0.65 mas
Distance	121 ± 3 ly (37.1 ± 0.9 pc)
Absolute magnitude (MV)	4.598 /
Details
Mass	3–4 M☉
Radius	130 R☉
Luminosity	1,900 L☉
Temperature	3,350 K
Rotational velocity (v sin i)	84 km/s
Orbit
Companion	CCDM 15245+3722 C
Period (P)	260.1 yr
Semimajor axis (a)	1.463"
Eccentricity (e)	0.59
Inclination (i)	135.4°
Longitude of the node (Ω)	174.9°
Periastron epoch (T)	1865
Other designations
Alkalurops, Inkalunis, Icalurus, Clava, Venabulum, 51 Boötis, HR 5733+HR 5734, HD 137391+HD 137392, NN 3903+NN 3904, BD+37°2636+BD 37°2637, FK5 568, HIP 75411+HIP 75415, SAO 64686+SAO 64687, GC 20724+GC 20725, ADS 9626, CCDM 15245+3722.
Database references
SIMBAD	data
Database references
SIMBAD	data
Data sources:
Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.)
Database references
SIMBAD	data

Mu Boötis (μ Boo, μ Boötis) is a triple star system in the constellation Boötes. It has the traditional name Alkalurops (also Inkalunis, Clava, and Venabulum), and the Flamsteed designation 51 Boötis. Mu Boötis is approximately 121 light-years from Earth.

The name Alkalurops is from Greek καλαύροψ kalaurops "shepherd's staff", through the Arabic.

It is known as 七公六 (the Sixth Star of the Seven Excellencies) in Chinese^[1].

The primary component, μ¹ Boötis, is a yellow-white F-type subgiant with an apparent magnitude of +4.31.

Position

Mu^1,2 Boötis

Separated from the primary by 108 arcseconds in the sky is the binary star μ² Boötis, which has a combined spectral type of G1V and a combined brightness of +6.51 magnitudes. The components of μ² Boötis have apparent magnitudes of +7.2 and +7.8 and are separated by 2.2 arcseconds. They complete one orbit about their common centre of mass every 260 years.

See also

• Mu Boötis in fiction

References

• HR 5733
• HR 5734
• CCDM J15245+3722
• Image Mu Boötis

1. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 26 日

Components

NAME	Right ascension	Declination	Apparent magnitude (V)	Spectral type	Database references
ADS 9626 B (ADS 9626 Aa)	15h 24m 36s	+37° 23'			Simbad
ADS 9626 C (CCDM J15245+3722BC)	15h 24m 30.8663s	+37° 20' 50.28	6.5	G1V	Simbad