2 Lupi

2 Lupi
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lupus
Right ascension 15h 17m 49.83809s[1]
Declination −30° 08′ 55.2165″[1]
Apparent magnitude (V) 4.33[2]
Characteristics
Evolutionary stage giant
Spectral type K0 IIIa CH-1[3]
B−V color index 1.100±0.004[4]
Astrometry
Radial velocity (Rv)−2.91±0.15[5] km/s
Proper motion (μ) RA: −10.16[1] mas/yr
Dec.: −3.66[1] mas/yr
Parallax (π)10.01 ± 0.21 mas[1]
Distance326 ± 7 ly
(100 ± 2 pc)
Absolute magnitude (MV)−0.65[4]
Details
Radius11.0+0.7
−0.8[5] R☉
Luminosity65.6±0.8[5] L☉
Surface gravity (log g)2.84[2] cgs
Temperature4,953+197
−148[5] K
Metallicity [Fe/H]0.11[2] dex
Other designations
f Lupi, 2 Lup, NSV 7012, CD−29°11630, FK5 3207, HD 135758, HIP 74857, HR 5686, SAO 183346[6]
Database references
SIMBADdata

2 Lupi is a single[7] star in the southern constellation of Lupus,[6] located 326 light-years away from the Sun.[1] It has the Bayer designation f Lupi; 2 Lupi is the Flamsteed designation. This object is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.33.[2] It is moving closer to the Earth with a heliocentric radial velocity of −3 km/s.[5]

This is an aging giant star with a stellar classification of K0 IIIa CH-1.[3] The suffix notation indicates abnormally weak lines of carbyne. Having exhausted the hydrogen at its core, the star evolved away from the main sequence by expanding to 11[5] times the Sun's radius. The star is radiating 65.6[5] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,953 K.[5] It is a suspected variable star of unknown type.[8]

  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 Cite error: The named reference McWilliam1990 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference perkins1989 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ a b c d e f g h Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  6. ^ a b 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 Samus2017 was invoked but never defined (see the help page).