Y Lyncis

Y Lyncis

A visual band light curve for Y Lyncis, adapted from Percy et al. (2001).[1] The top panel shows the brightness variation over a period of several years, and the lower panel shows shorter time scale variations.
Observation data
Epoch J2000      Equinox J2000
Constellation Lynx
Right ascension 07h 28m 11.61657s[2]
Declination +45° 59′ 26.2295″[2]
Apparent magnitude (V) 6.2 - 8.9[3]
Characteristics
Spectral type M6S Ib[4]
Variable type SRc[4]
Astrometry
Radial velocity (Rv)5.50±0.6[5] km/s
Proper motion (μ) RA: −1.278[2] mas/yr
Dec.: −4.067[2] mas/yr
Parallax (π)2.8068 ± 0.1138 mas[2]
Distance1,160 ± 50 ly
(360 ± 10 pc)
Details
Mass1.5 - 2.0[3] M☉
Radius580[3] R☉
Luminosity10,765[6] L☉
Surface gravity (log g)0.0[7] cgs
Temperature3,200[7] K
Metallicity [Fe/H]−0.19[7] dex
Other designations
Y Lyn, HD 58521, BD+46°1271, HIP 36288, SAO 41784
Database references
SIMBADdata

Y Lyncis is a semiregular variable star in the constellation Lynx. It is an asymptotic giant branch star of spectral type M6S, with a luminosity class of Ib, indicating a supergiant luminosity. It is around 1,160 light years away.

Y Lyncis ranges in brightness from magnitude 6.2 to 8.9. Its changes in brightness are complex with at least two different periods showing. The General Catalogue of Variable Stars lists a period of 110 days.[8] More recent studies show a primary pulsation period of 133 days, with and a long secondary period with an amplitude of 0.2 magnitudes and duration 1,300 days. The long secondary period variations are possibly caused by long-lived convection cells.[9]

Y Lyncis has a mass around 1.5-2.0 M☉ and a luminosity around 10,000 L☉. It is a thermally pulsing asymptotic giant branch star, an evolved star with a carbon-oxygen core that is fusing helium in a shell and hydrogen in a separate shell.[10] It is also an S-type star, where third dredge-ups have brought some carbon to the surface, but not enough to create a carbon star.[6]

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  2. ^ a b c d e Cite error: The named reference dr3 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Szatmary was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference percy2006 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference pulkovo was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference guandalini was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference soubiran was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference gcvs was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference percy2009 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference agb was invoked but never defined (see the help page).