4 Lacertae

4 Lacertae
Observation data
Epoch J2000      Equinox J2000
Constellation Lacerta
Right ascension 22h 24m 30.99149s[1]
Declination +49° 28′ 35.0106″[1]
Apparent magnitude (V) 4.55[2]
Characteristics
Evolutionary stage Blue supergiant (blue loop)[3]
Spectral type A0 Ib[4]
B−V color index 0.092±0.034[2]
Astrometry
Radial velocity (Rv)−26.0±1.7[2] km/s
Proper motion (μ) RA: −5.274(82)[1] mas/yr
Dec.: −3.303(96)[1] mas/yr
Parallax (π)1.2656 ± 0.0891 mas[1]
Distance2,600 ± 200 ly
(790 ± 60 pc)
Absolute magnitude (MV)−4.42[5]
Details
Mass19+13
−8[6] M☉
Radius59[6] R☉
Luminosity62,000[6] L☉
Surface gravity (log g)2.18[6] cgs
Temperature11,800[6] K
Metallicity [Fe/H]0.28±0.04[7] dex
Rotational velocity (v sin i)28±3[6] km/s
Age25.1±2.5[8] Myr
Other designations
4 Lac, BD+48° 3715, HD 212593, HIP 110609, HR 8541, SAO 51970, 2MASS J22243097+4928351[9]
Database references
SIMBADdata

4 Lacertae is a single[10] blue supergiant star in the northern constellation Lacerta, located about 2,600 light years away.[1] This object visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.55.[2] It is moving closer to the Earth with a heliocentric radial velocity of −26 km/s.[2] This star is a suspected member of the Lac OB1 association.[3][5]

This blue supergiant star has a stellar classification of A0 Ib.[4] The surface abundances show evidence of material that has been processed via the CNO cycle at the core.[3] It has ten[8] times the mass of the Sun and has expanded to about 59[6] times the Sun's radius. The star is around 25[8] million years old and is spinning with a projected rotational velocity of 28 km/s.[6][1] It is believed to be a blue loop star that has already spent time as a red supergiant after fusing the hydrogen within its core.

  1. ^ a b c d e f g Cite error: The named reference Gaia DR3 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Yüce2005 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gray1987 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Kaltcheva2009 was invoked but never defined (see the help page).
  6. ^ a b c d e f g h Cite error: The named reference markova was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Gáspár2016 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).