AR Aurigae

AR Aurigae

A visual band light curve for AR Aurigae, adapted from Johansen (1970)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension 05h 18m 18.896s[2]
Declination +33° 46′ 02.52″[2]
Apparent magnitude (V) 6.144[3]
Characteristics
Spectral type B9V + B9.5V[4]
U−B color index −0.18[5]
B−V color index −0.06[5]
Variable type Algol[6]
Astrometry
Radial velocity (Rv)25.4±0.9[7] km/s
Proper motion (μ) RA: +15.254[2] mas/yr
Dec.: −29.225[2] mas/yr
Parallax (π)7.0735 ± 0.0461 mas[2]
Distance461 ± 3 ly
(141.4 ± 0.9 pc)
Absolute magnitude (MV)1.11/1.17[8]
Details
AR Aur A
Mass2.552±0.008[4] M☉
Radius1.781[9] R☉
Luminosity41[8] L☉
Surface gravity (log g)4.33[4] cgs
Temperature10,950±150[4] K
Rotational velocity (v sin i)10[9] km/s
AR Aur B
Mass2.367±0.008[4] M☉
Radius1.816[9] R☉
Luminosity34[8] L☉
Surface gravity (log g)4.28[4] cgs
Temperature10,350±150[4] K
Rotational velocity (v sin i)11[9] km/s
Other designations
17 Aur, BD+33°1002, HD 34364, HIP 24740, HR 1728, SAO 57858, PPM 70158
Database references
SIMBADdata

AR Aurigae (AR Aur), also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.[10]

Both components are blue-white B-type main-sequence stars that do not fill their Roche lobes. The system has a mean apparent magnitude of +6.15. However, the orbit of the stars are oriented in such a way that they periodically eclipse each other, so AR Aurigae is a variable star and its brightness varies from magnitude +6.15 to +6.82 with a period of 4.13 days.[6]

The primary component of AR Aurigae is known to be a mercury-manganese star, also known as an HgMn star. As the name implies, these stars have over-abundances of the elements mercury and manganese, and also often xenon and other elements.[4] Because AR Aurigae is an eclipsing binary (in fact, it is the only known eclipsing binary with a mercury-manganese star), accurate characterization of its parameters has been made possible. Based on the light-time effect observed from the stars, it is inferred that there is a third star with a mass of 0.54 M☉, orbiting at a separation of 13 au every 23.7 years.[4]

  1. ^ Cite error: The named reference Johansen was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference dr3 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference TYC2 was invoked but never defined (see the help page).
  4. ^ a b c d e f g h i Cite error: The named reference Folsom was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference UBV was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference GCRV was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference nordstrom1994 was invoked but never defined (see the help page).
  9. ^ a b c d Cite error: The named reference eker2014 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).