Upsilon Capricorni

Upsilon Capricorni
Location of υ Capricorni (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Capricornus
Right ascension 20h 40m 02.94518s[1]
Declination −18° 08′ 19.1664″[1]
Apparent magnitude (V) 5.17[2]
Characteristics
Spectral type M1 III[3]
B−V color index +1.65[2]
Astrometry
Radial velocity (Rv)−12.3±1.6[4] km/s
Proper motion (μ) RA: −23.503[1] mas/yr
Dec.: −22.157[1] mas/yr
Parallax (π)4.4702 ± 0.2352 mas[1]
Distance730 ± 40 ly
(220 ± 10 pc)
Absolute magnitude (MV)−1.09[5]
Details
Radius76.36+8.05
−14.16[1] R☉
Luminosity1,283.0±76.5[1] L☉
Temperature3,953+427
−193[1] K
Metallicity [Fe/H]−0.08[5] dex
Other designations
υ Cap, 15 Capricorni, NSV 25208, BD−18°5738, FK5 773, HD 196777, HIP 101984, HR 7900, SAO 163779[6]
Database references
SIMBADdata

Upsilon Capricorni, Latinized from υ Capricorni, is a solitary[7] star in the southern constellation of Capricornus. It has a reddish hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.17.[2] The star is about 730 light years from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −12 km/s.[4] It is 0.22 degree north of the ecliptic, so is subject to lunar occultations.[8][9]

This is an aging red giant star on the asymptotic giant branch[10] with a stellar classification of M1 III,[3] a star that has exhausted the supply of hydrogen at its core then cooled and expanded. At present it has 76[1] times the radius of the Sun. It is a suspected variable star of unknown type with a brightness that has been measured ranging from a peak of 5.19 down to 5.24.[11] The star is radiating 1,283[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,953 K.[1]

  1. ^ a b c d e f g h i j k l Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Barnes1978 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1988 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference White1987 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Dunham1973 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggen1992 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Samus2017 was invoked but never defined (see the help page).