2 Vulpeculae

2 Vulpeculae

A light curve for ES Vulpeculae, adapted from Lynds (1959)[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Vulpecula
2 Vul A
Right ascension 19h 17m 43.6354s[2]
Declination +23° 01′ 31.9418″[2]
Apparent magnitude (V) 5.43[3]
2 Vul B
Right ascension 19h 17m 43.7343s[4]
Declination +23° 01′ 30.8604″[4]
Characteristics
Spectral type B1 IV[5]
B−V color index 0.020±0.003[3]
Variable type β Cep[6]
Astrometry
2 Vul A
Radial velocity (Rv)+1.0±4.2[3] km/s
Proper motion (μ) RA: +0.956±0.041[2] mas/yr
Dec.: −6.636±0.087[2] mas/yr
Parallax (π)1.8212 ± 0.0880 mas[2]
Distance1,790 ± 90 ly
(550 ± 30 pc)
Absolute magnitude (MV)−2.35[3]
2 Vul B
Proper motion (μ) RA: −0.170±0.038[4] mas/yr
Dec.: −5.324±0.073[4] mas/yr
Parallax (π)1.7131 ± 0.0757 mas[4]
Distance1,900 ± 80 ly
(580 ± 30 pc)
Details
Mass12.5±0.6[7] M☉
Luminosity (bolometric)21,922[8] L☉
Temperature26,850[8] K
Metallicity [Fe/H]−0.06±0.10[9] dex
Rotational velocity (v sin i)270[10] km/s
Age12.6±0.7[7] Myr
Other designations
2 Vul, ES Vul, BD+22°3648, HD 180968, HIP 94827, HR 7318, SAO 87036, WDS 19177+2302[11]
Database references
SIMBADdata

2 Vulpeculae is a binary star[12] system in the northern constellation of Vulpecula, located around 1,800 light years away[2] from the Sun. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 5.43.[3]

2 Vulpeculae is a double-lined spectroscopic binary;[12] as of 2002, the pair had an angular separation of 1.72″ along a position angle of 127.2°.[13]

The primary component of the binary is a rapidly rotating Be star[14] with a stellar classification of B1 IV.[5] It is a variable star with an amplitude of 0.06 magnitude and a period of 0.6096 days, tentatively classified as Beta Cephei variable.[6] The variability was discovered in 1959,[15] and it has been assigned the variable star designation ES Vulpeculae.[6]

  1. ^ Cite error: The named reference Lynds was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Gaia DR3 for A was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference Gaia DR3 for B was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference mk was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference hohle2010 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Gáspár2016 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Abt2002 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference chini2012 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Roberts2011 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Balona1995 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference lynds was invoked but never defined (see the help page).