31 Lyncis

31 Lyncis

A light curve for BN Lyncis, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Lynx
Right ascension 08h 22m 50.11000s[2]
Declination +43° 11′ 17.2724″[2]
Apparent magnitude (V) +4.25[3]
Characteristics
Spectral type K4+ III[4]
B−V color index 1.550±0.003[5]
Variable type SRd[6]
Astrometry
Radial velocity (Rv)+24.56±0.22[5] km/s
Proper motion (μ) RA: −25.16±0.36[2] mas/yr
Dec.: −99.23±0.21[2] mas/yr
Parallax (π)8.53 ± 0.25 mas[2]
Distance380 ± 10 ly
(117 ± 3 pc)
Absolute magnitude (MV)−1.09[5]
Details[7]
Mass1.95±0.18 M☉
Radius53.27+1.64
−1.55 R☉
Luminosity782.4±60.3 L☉
Surface gravity (log g)1.46±0.12[8] cgs
Temperature3,921±19[8] K
Metallicity [Fe/H]−0.06±0.05[8] dex
Age1.32±0.23 Gyr
Other designations
Alsciaukat, 31 Lyn, BN Lyn, NSV 4030, BD+43°1815, FK5 314, GC 11401, HD 70272, HIP 41075, HR 3275, SAO 42319[9]
Database references
SIMBADdata

31 Lyncis is the fourth-brightest star in the constellation of Lynx. It has the traditional name Alsciaukat, pronounced /ælʃiˈɔːkæt/.[10] The orange-hued star is visible to the naked eye with a baseline apparent visual magnitude of +4.25.[3] It is a single[11] star located about 380 light years away from the Sun, based on parallax,[2] and is moving further away with a heliocentric radial velocity of +25 km/s.[5]

This object is an aging giant star with a stellar classification of K4+ III.[4] A 1993 study found that it varied in brightness by 0.05 magnitude over 25 to 30 days.[12] On the other hand, a 2002 study of the Hipparcos data found a period of 3.5 days.[13] It is classified as a semiregular variable with a brightness that ranges from 4.21 to as low as 4.27, and has the variable star designation BN Lyncis.[6]

31 Lyncis is 1.3 billion years old with almost double the mass of the Sun. With the supply of hydrogen at its core exhausted, the star has expanded to 53 times the Sun's radius. It is radiating around 782[7] times the Sun's luminosity from its swollen photosphere at an effective temperature of 3,921 K.[8]

  1. ^ Cite error: The named reference CDS was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference ducati was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Keenan1989 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Baines2017 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference sharma2016 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference IAU-LSN was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Percy1993 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Koen was invoked but never defined (see the help page).