*** Welcome to piglix ***

Y Lyncis

Y Lyncis
Observation data
Epoch J2000      Equinox J2000
Constellation Lynx
Right ascension 07h 28m 11.61802s
Declination +45° 59′ 26.2366″
Apparent magnitude (V) 6.2 - 8.9
Characteristics
Spectral type M6S Ib
Variable type SRc
Astrometry
Radial velocity (Rv) 5.50 ± 0.6 km/s
Proper motion (μ) RA: 0.23 ± 1.17 mas/yr
Dec.: −3.41 ± 0.60 mas/yr
Parallax (π) 3.95 ± 0.95mas
Distance approx. 800 ly
(approx. 250 pc)
Details
Mass 1.5 - 2.0 M
Radius 580 R
Luminosity 10,765 L
Surface gravity (log g) 0.0 cgs
Temperature 3,200 K
Metallicity [Fe/H] −0.19 dex
Other designations
Y Lyn, HD 58521, BD +46 1271, HIP 36288, SAO 41784

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 800 light years away.

Y Lyncis ranges in brightness from magnitude 6.8 to 8.9. Its changes in brightness are complex with at least two different periods showing. The General Catalogue of Variable Starslists a period of 110 days. 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.

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. 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.


...
Wikipedia

...