16 Vulpeculae

16 Vulpeculae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Vulpecula
Right ascension 20h 02m 01.43152s[1]
Declination +24° 56′ 16.9534″[1]
Apparent magnitude (V) 5.787[2] 5.93 + 6.22[3]
Characteristics
Spectral type F2 III[4]
U−B color index +0.10[5]
B−V color index +0.37[5]
Astrometry
Radial velocity (Rv)−37.00±3.7[6] km/s
Proper motion (μ) RA: 89.31[1] mas/yr
Dec.: 69.44[1] mas/yr
Parallax (π)14.71 ± 0.50 mas[1]
Distance222 ± 8 ly
(68 ± 2 pc)
Absolute magnitude (MV)2.47[7]
Orbit[8]
Period (P)1201 yr
Semi-major axis (a)2.687″
Eccentricity (e)0.932
Inclination (i)79.0°
Longitude of the node (Ω)84.5°
Periastron epoch (T)B 1863.7
Argument of periastron (ω)
(secondary)		276.5°
Details
16 Vul A
Mass1.34[9] M☉
Luminosity31.13[10] L☉
Surface gravity (log g)3.76±0.14[9] cgs
Temperature6,888±234[9] K
Metallicity [Fe/H]0.17[11] dex
Rotational velocity (v sin i)136.1±6.8[7] km/s
Age742[9] Myr
Other designations
16 Vul, BD+24° 3977, HD 190004, HIP 98636, HR 7657, SAO 88098[12]
Database references
SIMBADdata

16 Vulpeculae is a binary star system in the northern constellation Vulpecula.[1] It has a combined apparent visual magnitude of 5.787,[2] which is near the lower limit of visibility to the naked eye. Based upon an annual parallax shift of 14.71±0.50[1] as seen from Earth's orbit, it is located about 222 light years away. The system is moving closer to the Sun with a heliocentric radial velocity of about −37 km/s.[6] It will make its closest approach in about 0.9 million years, coming within 155 light-years (47.42 pc).[10]

The pair orbit each other with an estimated period of 1,201 years and an orbital eccentricity of 0.932.[8] The magnitude 5.93 primary, component A, displays a stellar classification of F2III,[12] matching an aging F-type giant star. This star is spinning rapidly with a projected rotational velocity of 136 km/s.[7] This is giving the star an oblate shape with an equatorial bulge that is an estimated 21% larger than the polar radius.[13] It is 742[9] million years old with 1.34[9] times the mass of the Sun. The star is radiating 31[10] times the Sun's luminosity from its photosphere at an effective temperature of about 6,888 K.[9]

  1. ^ a b c d e f g Cite error: The named reference HIP was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference TYC2 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Cowley1974 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference EgUBV was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Holmberg2007 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference vonEiff2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference ORB6 was invoked but never defined (see the help page).
  9. ^ a b c d e f g Cite error: The named reference David2015 was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference belle2012 was invoked but never defined (see the help page).