Alpha Lacertae

α Lacertae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lacerta
Right ascension 22h 31m 17.5010s[1]
Declination +50° 16′ 56.969″[1]
Apparent magnitude (V) 3.777[1]
Characteristics
Spectral type A1V[1]
U−B color index 0.00[2]
B−V color index +0.01[2]
R−I color index −0.03[2]
Astrometry
Radial velocity (Rv) −4.0 ± 2[1] km/s
Proper motion (μ) RA: 137.22[1] mas/yr
Dec.: 17.15[1] mas/yr
Parallax (π) 31.86 ± 0.54[1] mas
Distance 102 ± 2 ly
(31.4 ± 0.5 pc)
Absolute magnitude (MV) 1.29[3]
Details
Mass ~2[4] M
Radius 1.9[5] R
Luminosity (bolometric) 27[4] L
Temperature 9200[4] K
Rotational velocity (v sin i) 146[2] km/s
Other designations
α Lac, Alpha Lacertae, Alpha Lac, 7 Lacertae, 7 Lac, BU 703A, ADS 16021 A, BD+49°3875, CCDM J22313+5017A, FK5 848, GC 31471, HD 213558, HIP 111169, HR 8585, IDS 22272+4946 A, PPM 40777, SAO 34542, WDS 22131+5017A.[1][6]
Database references
SIMBAD data

Alpha Lacertae (Alpha Lac, α Lacertae, α Lac) is an A-type main sequence star in the constellation of Lacerta.[1] It is the brightest star in Lacerta and has an apparent visual magnitude of approximately 3.777.[1][4]

Visual companion

CCDM J22313+5017B
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lacerta
Right ascension 22h 31m 13.2s[7]
Declination +50° 17′ 09″[7]
Apparent magnitude (V) 11.8[7]
Characteristics
Spectral type A5[7]
B−V color index 0.0[7]
Position (relative to α Lacertae)
Epoch of observation 1925
Angular distance 36.3 [6]
Position angle 294° [6]
Other designations
BU 703B, ADS 16021 B, BD+49°3875B, IDS 22272+4946 B, WDS 22131+5017B.[1][6]
Database references
SIMBAD data

The star has a visual companion, CCDM J22313+5017B, of spectral type A and apparent visual magnitude 11.8, approximately 36 arcseconds away.[6][7] The companion is optical, a chance line-of-sight coincidence.[2]

References

  1. ^ a b c d e f g h i j k l * alf Lac -- Star in double system, database entry, SIMBAD. Accessed on line September 3, 2008.
  2. ^ a b c d e HR 8585, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 3, 2008.
  3. ^ From apparent magnitude and parallax.
  4. ^ a b c d Alpha Lac, Jim Kaler, Stars. Accessed on line September 3, 2008.
  5. ^ HD 213558, database entry, Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS), 3rd edition, L. E. Pasinetti-Fracassini, L. Pastori, S. Covino, and A. Pozzi, CDS ID II/224. Accessed on line September 3, 2008.
  6. ^ a b c d e Entry 22313+5017, discoverer code BU 703, The Washington Double Star Catalog, United States Naval Observatory. Accessed on line September 3, 2008.
  7. ^ a b c d e f BD+49 3875B -- Star in double system, database entry, SIMBAD. Accessed on line September 3, 2008.