5 Serpentis

5 Serpentis
Observation data
Epoch J2000      Equinox J2000
Constellation Serpens
Right ascension 15h 19m 18.79710s[1]
Declination +01° 45′ 55.4685″[1]
Apparent magnitude (V) 5.10[2]
Characteristics
Spectral type F8 IV[3][4]
B−V color index 0.50[2]
Astrometry
Radial velocity (Rv)+54.3±0.1[5] km/s
Proper motion (μ) RA: +372.21[1] mas/yr
Dec.: −513.59[1] mas/yr
Parallax (π)39.40 ± 0.29 mas[1]
Distance82.8 ± 0.6 ly
(25.4 ± 0.2 pc)
Absolute magnitude (MV)3.02[6]
Details
5 Ser A
Mass1.16[2] M☉
Luminosity5[2] L☉
Surface gravity (log g)4.07[4] cgs
Temperature6,025±177[2] K
Metallicity [Fe/H]+0.02[7] dex
Rotational velocity (v sin i)4.8[4] km/s
Age5.27[2] Gyr
Other designations
5 Ser, MQ Ser, BD+02° 2944, HD 136202, HIP 74975, HR 5694, SAO 120946, WDS J15193+0146A[8]
Database references
SIMBADdata

5 Serpentis is a wide binary star[9] system in Serpens Caput, the western section of the equatorial constellation of Serpens. It is faintly visible to the naked eye with an apparent visual magnitude of 5.10.[2] Based upon an annual parallax shift of 39.40±0.29 mas[1] as viewed from Earth's orbit, it is located 83 light years away. The brighter member is an IAU radial velocity standard star,[10] and it is moving away from the Sun with a heliocentric radial velocity of +54.3 km/s.[5] The system made its closest approach to the Sun about 153,000 years ago at a separation of 68 ly (20.7 pc).[6]

The primary, component A, is an F-type subgiant star with a stellar classification of F8 IV,[3][4] a star that has exhausted its core hydrogen and is evolving to become a red giant. The star was once thought to be a BY Draconis variable with the variable star designation MQ Ser,[11] but has been found not to be.[12] From observations made between 1975 and 1980, Bakos (1983) reported random, small brightness variations with an amplitude of less than 0.03 magnitude, plus three flare events that increased the brightness by 0.1 magnitudes.[13] However, Scarfe (1985) noted that these observations may instead be due to normal observational error.[10]

The common proper motion companion, component B, is a magnitude 10.11 star at an angular separation of 11.4″ along a position angle of 35°. It has an estimated orbital period of 3,371 years.[9] According to Hoffleit (1991), if this is a variable star it may account for the observations of Bakos (1983).[14]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Luck2015 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference gray2001 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Mallik2003 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Maldonado2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Tokovinin2014 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Scarfe1985 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Kholopov1985 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference AAVSO was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Bakos1983 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Hoffleit1991 was invoked but never defined (see the help page).