Cor Caroli

Database links to α Canum Venaticorum / Cor Caroli

Double star α Canum Venaticorum / Cor Caroli
Observation dates equinox :  J2000.0 , epoch : J2000.0
AladinLite
Constellation	Hunting dogs
Right ascension	12 h 56 m 02 s
declination	+ 38 ° 19 ′ 06 ″
Apparent brightness	2.80 mag
Position of the companion
Angular distance	19.3 ″
Position angle	224 °
Astrometry
parallax	(30.38 ± 0.09) mas
distance	107 ly (33 pc )
Individual data
Names	A / α 2 ; B / α 1
Observation data:
Apparent brightness	A / α 2	2.88 mag 2.86 mag to 2.93 mag
	B / α 1	5.60 mag
Typing:
Spectral class	A / α 2	A0VpSiEu
	B / α 1	F2 V
B − V color index	A / α 2	−0.12
	B / α 1	+0.34
U − B color index	A / α 2	−0.32
	B / α 1	-0.03
Physical Properties:
Dimensions	A / α 2	3 M ☉
	B / α 1	1.5 M ☉
radius	A / α 2	2.7 R ☉
	B / α 1	1.7 R ☉
Luminosity	A / α 2	113 L ☉
	B / α 1	5.6 L ☉
Effective temperature	A / α 2	11450 K
	B / α 1	6785 K
Rotation time	A / α 2
	B / α 1	5.47 d
Other names and catalog entries
Bayer name α Canum venaticorum Flamsteed name 12 Canum venaticorum Bonn survey BD + 39 ° 2580 Bright Star Catalog HR 4915 HR 4914 Henry Draper Catalog HD 112413 HD 112412 SAO catalog SAO 63257 SAO 63256 Tycho catalog TYC 3021-2645-1 [1] TYC 3021-2646-1 [2] Hipparcos catalog HIP 63125 HIP 63121 WDS catalog WDS J12560 + 3819 Further designations: Cor Caroli, Struve 1692, IDS 12514 + 3851   FK5 485

α Canum Venaticorum ( Alpha Canum Venaticorum , α CVn for short ) is the brightest star in the constellation Hunting Dogs (Latin Canes Venatici ). He is also known as Cor Caroli ("Heart of Karl", in honor of Charles II, King of England). α Canum Venaticorum is a double star that can be separated even with small telescopes ( lens opening from 5 centimeters) .

Location of α Canum Venaticorum within the local bladder (scale 25 ly.)

The main star is the prototype of a class of variable stars called the Alpha ² -Canum Venaticorum stars . They have a strong magnetic field, which creates star spots comparable to sunspots on a huge scale. Due to these spots, their brightness changes more or less strongly in the course of the rotation. The brightness of the main star, α ²  Canum Venaticorum, fluctuates between +2.84 mag and +2.94 mag with a period of 5.47 days. The main star's spectral type is A0. The companion star of the spectral type F0, located at an angular distance of 19.3 ″ at a position angle of 224 degrees, is much weaker. Its brightness is 5.6 mag. α Canum Venaticorum is about 110 light years away ( Hipparcos catalog ).

The proper name Cor Caroli goes back to the historical constellation Cor Caroli , in which α CVn was the brightest star and was fully referred to as Cor Caroli Regis Martyris .

The IAU has on 20 July 2016 the proper name Cor Caroli as standardized proper names α only for the star ² set. The star α ¹ therefore has no proper name.

Individual evidence

1. ^ STF 1692. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on November 1, 2018 . 
2. ↑ ^{a b c d e} alf02 CVn. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed on November 1, 2018 . 
3. ↑ ^{a b c d e f} alf01 CVn. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed on November 1, 2018 . 
4. ↑ alf 2 CVn. In: VSX. AAVSO, accessed November 1, 2018 . 
5. ↑ ^{a b c d e} Cor Caroli. Jim Kaler, accessed November 1, 2018 . 
6. ↑ Bulletin of the IAU Working Group on Star Names, No. 1, July 2016. (PDF) Retrieved November 9, 2016 (English, 184 KiB).