A visual bandlight curve for UX Lyncis. The top panel shows the variation over a period of years, and the lower plot shows the variation over a period of months. Adapted from Percy and Wilson (2001)[1]
The stellar classification of this star is M3III,[5] while the infrared spectrum matches a class of M6III.[6] It is an aging red giant on the asymptotic giant branch that has exhausted the supply of both hydrogen and helium in its core, then cooled and expanded. At present it has 128[2] times the radius of the Sun, which is equivalent to 0.60 AU or 60% of the distance from the Sun to the Earth. On average, it radiates a luminosity approximately 1,766 times that of the Sun from its swollen photosphere at an effective temperature of 3,302 K.[2] Infrared observations show little or no evidence for an oxygen-rich dusty shell around the star.[4]
The variability of this star was reported by R. L. Walker in 1970 from the U.S. Naval Observatory.[10] It was given its variable star designation in 1973.[11] UX Lyncis has been classified as a semiregular variable ranging from magnitude 6.6 down to 6.78.[3] Its changes in brightness are complex, with a shorter period of 37.3 days due to the star's pulsations, and a longer period of 420 days possibly due to the star's rotation or convectively induced oscillatory thermal (COT) mode.[1] There is some evidence for an additional weak variability with a 29 day period.[12]
^ abSato, K.; Kuji, S. (November 1990). "MK classification and photometry of stars used for time and latitude observations at Mizusawa and Washington". Astronomy & Astrophysics Supplement Series. 85: 1069. Bibcode:1990A&AS...85.1069S.
^Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 2. Sky Publishing Corporation and the European Space Agency. p. 620. ISBN0-933346-83-2.
^Walker, R. L. (July 1970). "Light Variations of BD+39°2193". Information Bulletin on Variable Stars. 447: 1. Bibcode:1970IBVS..447....1W.
