V420 Aurigae

V420 Aurigae

A light curve for V420 Aurigae, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension 05h 22m 35.23140s[2]
Declination +37° 40′ 33.6386″[2]
Apparent magnitude (V) 7.35 - 7.51[3]
Characteristics
Spectral type B0IVpe[4]
U−B color index −0.88[5]
B−V color index +0.16[5]
Variable type HMXB[6] + γ Cas[3]
Astrometry
Radial velocity (Rv)−20.5±4.4[7] km/s
Proper motion (μ) RA: +1.305 mas/yr[2]
Dec.: −3.999 mas/yr[2]
Parallax (π)0.7214 ± 0.0196 mas[2]
Distance4,500 ± 100 ly
(1,390 ± 40 pc)
Details
HD 34921 A
Mass17.5[8] M☉
Radius10.8[2] R☉
Luminosity1,673[9] L☉
Surface gravity (log g)3.5[4] cgs
Temperature30,000[4] K
Metallicity [Fe/H]−0.39[2] dex
Rotational velocity (v sin i)240±4[10] km/s
Other designations
V420 Aur, BD+37°1160, HD 34921, HIP 25114, SAO 57950[11]
Database references
SIMBADdata

V420 Aurigae is a high-mass star with an inferred compact companion. Closely orbiting each other every 0.8 days, they are a source of X-ray emission.[6]

These coordinates were identified as an X-ray source using the Uhuru satellite in 1978, then associated with the star V420 Aurigae by V. F. Polcaro and associates in 1984.[12] The spectrum of the star shows rapid variation in the lines of singly-ionized iron and Balmer line emission, with these varying on a time scale of less than 300 seconds. This lends support to the presence of a compact companion.[13] The system displays an infrared excess, suggesting it has an orbiting circumstellar envelope of gas and possibly dust.[4] The system appears to be positioned at the center of an irregular, wispy nebula that was detected in the infrared band. One of the two filaments in this nebula appears to be connected with the system.[12]

  1. ^ Cite error: The named reference CDS was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference dr3 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference vsx was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Polcaro_et_al_1990 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Lutz1972 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference pasp116_816 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Gontcharov was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference fortin2022 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Halbedel1996 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 Prišegen2019 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Rossi_et_al_1991 was invoked but never defined (see the help page).