6 Andromedae

For the galaxy, see Andromeda VI.
6 Andromedae
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 10m 27.23746s[1]
Declination +43° 32′ 38.4336″[1]
Apparent magnitude (V) 5.91[2]
Characteristics
Spectral type F5 V[3]
U−B color index −0.05[3]
B−V color index +0.450±0.004[2]
Astrometry
Radial velocity (Rv)−32.4±0.7[2] km/s
Proper motion (μ) RA: +209.057[1] mas/yr
Dec.: +138.052[1] mas/yr
Parallax (π)34.1008 ± 0.1650 mas[1]
Distance95.6 ± 0.5 ly
(29.3 ± 0.1 pc)
Absolute magnitude (MV)3.71[2]
Orbit[3]
Period (P)3,373±6 d
Periastron epoch (T)53116 ± 16 MJD
Argument of periastron (ω)
(secondary)		165.2±2.0°
Semi-amplitude (K1)
(primary)		8.75±0.09 km/s
Details
Mass1.30[4] M☉
Radius1.50+0.03
−0.06[1] R☉
Luminosity3.090+0.018
−0.017[1] L☉
Surface gravity (log g)4.09±0.14[4] cgs
Temperature6,425±218[4] K
Metallicity [Fe/H]−0.19±0.03[2] dex
Rotational velocity (v sin i)18[5] km/s
Age2.91[4] Gyr
Other designations
6 And, BD+42° 4592, FK5 3857, HD 218804, HIP 114430, HR 8825, SAO 52761, PPM 63896[6]
Database references
SIMBADdata

6 Andromedae is an astrometric binary star[7] system in the northern constellation of Andromeda. The designation comes from the star catalogue of John Flamsteed, first published in 1712. Its apparent visual magnitude is 5.91,[2] which is just bright enough to be visible to the naked eye under good seeing conditions. Based upon an annual parallax shift of 34.1 mas as seen from Earth,[1] it is around 96 light years from the Sun. It is moving closer to the Sun with a radial velocity of −32.4 km/s.[2] The system has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.272 arc seconds per annum.[8]

This is a single-lined spectroscopic binary with an orbital period of 9.2 years and an eccentricity of 0.3.[3] Some early observations of the star gave it a subgiant luminosity class and it was published in the Bright Star Catalogue as spectral class F5 IV. More modern measurements identify the visible component as an F-type main-sequence star with a stellar classification of F5 V.[3][9] The star is an estimated 2.9[4] billion years old with 1.3[4] times the mass of the Sun and 1.5[1] times the Sun's radius. It is radiating 3.1[1] times the Sun's luminosity from its photosphere at an effective temperature of around 6,425 K.[4] 6 Andromedae displays an infrared excess at a wavelength of 22 μm, which may indicate a circumstellar disk of warm dusty debris.[5]

The mass of the secondary component is roughly at or above that of the Sun. If it were a single, ordinary star, it should be readily visible as it would be just one magnitude fainter than the primary. The lack of conspicuous ultraviolet emission appears to rule out a white dwarf companion, so it may instead itself be a binary system consisting of two smaller stars having an orbital period between a week and a year.[3]

  1. ^ a b c d e f g h i j Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Griffin2012 was invoked but never defined (see the help page).
  4. ^ a b c d e f g Cite error: The named reference David2015 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Mizusaw2012 was invoked but never defined (see the help page).
  6. ^ "6 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-01.
  7. ^ Cite error: The named reference Frankowski2007 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Lepine2005 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference skiff was invoked but never defined (see the help page).