Pi Boötis

Pi Boötis

Observation data Epoch J2000      Equinox J2000
Constellation	Boötes
Right ascension	Template:RA
Declination	Template:DEC
Apparent magnitude (V)	4.49 (4.893 + 5.761)
Characteristics
Spectral type	B9 IIIp (MnHgSi) + A6 V
U−B Template:Engvar	−0.31
B−V Template:Engvar	−0.002±0.010
R−I Template:Engvar	−0.02
Astrometry
Radial velocity (Rv)	Template:Val km/s
Proper motion (μ)	RA: +13.922 mas/yr Dec.: +15.566 mas/yr
Parallax (π)	10.3357±0.1199 mas
Distance	Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)	–0.39
Details
π1 Boo
Mass	Template:Val Template:Solar mass
Radius	Template:Val Template:Solar radius
Luminosity	214 Template:Solar luminosity
Surface gravity (log g)	Template:Val cgs
Temperature	Template:Val K
Metallicity [Fe/H]	Template:Val dex
Rotational velocity (v sin i)	14.0 km/s
π2 Boo
Surface gravity (log g)	3.60±0.01 cgs
Temperature	7504Template:Su K
Metallicity [Fe/H]	0.580 dex
Rotational velocity (v sin i)	144 km/s
Other designations
Template:Odlist
π1 Boötis: Template:Odlist
π2 Boötis: Template:Odlist
Database references
π1 Boo
SIMBAD	data
π1 Boo
SIMBAD	data
Data sources:
Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.)

Pi Boötis is a candidate triple star system in the northern constellation of Boötes. Its name is a Bayer designation that is Latinized from π Boötis, and abbreviated Pi Boo or π Boo. This system is visible to the naked eye as a point of light with a combined apparent visual magnitude of 4.50. Based upon an annual parallax shift of Template:Val as seen from Earth, it is located roughly 316 light years from the Sun.

The brighter primary, component π¹ Boötis, has a visual magnitude of 4.89 and a stellar classification of B9 IIIp (MnHgSi), which suggests it is an evolved blue-white hued B-type giant star. It is a chemically peculiar star of the HgMn type, with a spectrum that displays anomalous overabundances of mercury, manganese, and silicon. This component is most likely a single-lined spectroscopic binary with an unknown companion.

Its magnitude 5.76 visible companion, π² Boötis, is a white-hued A-type main-sequence star with a class of A6 V. It is spinning rapidly with a projected rotational velocity of 144 km/s. As of 2010, the pair were separated by Template:Val arcseconds on the sky along a position angle of Template:Val. This corresponds to a projected separation of Template:Val. The odds that is a mere chance alignment is 0.85%.

Pi Boötis has the Chinese traditional star name 左攝提二 (Zuǒ shè tí èr).

External links

• HR 5475
• CCDM J14407+1625
• Image Pi Boötis