{{Short description|Star in the constellation Lynx}} {{Starbox begin}} {{Starbox image | image = 250px | caption = A visual band light 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)<ref name="Percy 2001"/> }} {{Starbox observe | epoch = J2000 | ra = {{RA|09|03|47.10789}}<ref name=GaiaDR2/> | dec = {{DEC|+38|44|31.6542}}<ref name=GaiaDR2/> | appmag_v = 6.6 - 6.78<ref name=AAVSOUX/> | constell = Lynx }} {{Starbox character | type = AGB<ref name=Sloan_Price_1998/> | class = M3III<ref name=Sato_Kuji_1990/> or M6III<ref name=Lebzelter_Hron_2003/> | b-v = {{val|1.356|0.011}}<ref name=Anderson_Francis_2012/> | u-b = | variable = SRb:<ref name=Sloan_Price_1998/> }} {{Starbox astrometry | radial_v = {{val|+38.60|0.64}}<ref name=Anderson_Francis_2012/> | prop_mo_ra = −17.176<ref name=GaiaDR2/> | prop_mo_dec = −20.823<ref name=GaiaDR2/> | parallax = 3.6035 | p_error = 0.4422 | parallax_footnote = <ref name=GaiaDR2/> | absmag_bol = −0.15<ref name=Anderson_Francis_2012/> }} {{Starbox detail | mass = | radius = {{val|128.38|0.92|9.89}}<ref name=GaiaDR2/> | luminosity = {{val|1766|242|fmt=commas}}<ref name=GaiaDR2/> | gravity = | temperature = {{val|3302|135|11}}<ref name=GaiaDR2/> | metal_fe = | rotational_velocity = | age_gyr = }} {{Starbox catalog | names = {{odlist | V=UX&nbsp;Lyn | HD=77443 | BD=+39°2193 | HIP=44481 | IRAS=09005+3856 | SAO=61226 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad=UX+Lyn }} {{Starbox end}}

'''UX Lyncis''' is a variable star in the faint northern constellation of Lynx, positioned about 3° to the south of the 4th magnitude star 10 Ursae Majoris.<ref name=Sinnott_Perryman_1997/> This is a red-hued star near the lower threshold of visibility to the naked eye, having an apparent visual magnitude that fluctuates around 6.70.<ref name=Anderson_Francis_2012/> It is located at a distance of approximately 900&nbsp;light years from the Sun based on parallax,<ref name=GaiaDR2/> and is drifting further away with a radial velocity of +39&nbsp;km/s.<ref name=Anderson_Francis_2012/>

The stellar classification of this star is M3III,<ref name=Sato_Kuji_1990/> while the infrared spectrum matches a class of M6III.<ref name=Lebzelter_Hron_2003/> 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<ref name=GaiaDR2/> times the radius of the Sun, which is equivalent to {{convert|128.38|solar radius|AU|2|disp=out|lk=on|abbr=on}} 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&nbsp;K.<ref name=GaiaDR2/> Infrared observations show little or no evidence for an oxygen-rich dusty shell around the star.<ref name=Sloan_Price_1998/>

The variability of this star was reported by R. L. Walker in 1970 from the U.S. Naval Observatory.<ref name=Walker1970/> It was given its variable star designation in 1973.<ref name="Kukarkin1973"/> UX Lyncis has been classified as a semiregular variable ranging from magnitude 6.6 down to 6.78.<ref name=AAVSOUX/> 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.<ref name="Percy 2001"/> There is some evidence for an additional weak variability with a 29 day period.<ref name=Percy_et_al_2003/>

== References == {{reflist|30em|refs=

<ref name=SIMBAD>{{cite simbad | title=UX Lyn | accessdate=2021-01-22 }}</ref>

<ref name=GaiaDR2>{{cite DR2|719225572598968832}}</ref>

<ref name=Sinnott_Perryman_1997>{{cite book | first1=Roger W. | last1=Sinnott | first2=Michael A. C. | last2=Perryman | title=Millennium Star Atlas | page=620 | volume=2 | year=1997 | isbn=0-933346-83-2 | publisher=Sky Publishing Corporation and the European Space Agency }}</ref>

<ref name="Kukarkin1973">{{cite journal | last1=Kukarkin | first1=B. V. | last2=Kholopov | first2=P. N. | last3=Kukarkina | first3=N. P. | last4=Perova | first4=N. B. | title=59th Name-List of Variable Stars | journal=Information Bulletin on Variable Stars | date=October 1973 | volume=834 |bibcode=1973IBVS..834....1K | url=https://ibvs.konkoly.hu/pub/ibvs/0801/0834.pdf | access-date=21 December 2024}}</ref>

<ref name=Walker1970>{{cite journal | title=Light Variations of BD+39°2193 | last=Walker | first=R. L. | journal=Information Bulletin on Variable Stars | volume=447 | page=1 | date=July 1970 | bibcode=1970IBVS..447....1W }}</ref>

<ref name=Sato_Kuji_1990>{{cite journal | title=MK classification and photometry of stars used for time and latitude observations at Mizusawa and Washington. | last1=Sato | first1=K. | last2=Kuji | first2=S. | journal=Astronomy & Astrophysics Supplement Series | volume=85 | page=1069 | date=November 1990 | bibcode=1990A&AS...85.1069S }}</ref>

<ref name=Sloan_Price_1998>{{cite journal | title=The Infrared Spectral Classification of Oxygen-rich Dust Shells | last1=Sloan | first1=G. C. | last2=Price | first2=S. D. | journal=The Astrophysical Journal Supplement Series | volume=119 | issue=2 | pages=141–158 | date=December 1998 | doi=10.1086/313156 | bibcode=1998ApJS..119..141S | doi-access=free }}</ref>

<ref name=Lebzelter_Hron_2003>{{cite journal | title=Technetium and the third dredge up in AGB stars. I. Field stars | last1=Lebzelter | first1=T. | last2=Hron | first2=J. | journal=Astronomy and Astrophysics | volume=411 | pages=533–542 | date=December 2003 | issue=3 | arxiv=astro-ph/0310018 | bibcode=2003A&A...411..533L | doi=10.1051/0004-6361:20031458 | s2cid=18879265 }}</ref>

<ref name=Anderson_Francis_2012>{{cite journal | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | s2cid=119257644 }}</ref>

<ref name=Percy_et_al_2003>{{cite journal | title=Multiperiodicity in Five Small-Amplitude Pulsating Red Giants | last1=Percy | first1=John R. | last2=Besla | first2=Gurtina | last3=Velocci | first3=Vince | last4=Henry | first4=Gregory W. | display-authors=1 | journal=The Publications of the Astronomical Society of the Pacific | volume=115 | issue=806 | pages=479–483 | date=April 2003 | doi=10.1086/374199 | bibcode=2003PASP..115..479P | s2cid=120018973 | doi-access=free }}</ref>

<ref name="Percy 2001">{{cite journal | display-authors=1 | last1=Percy | first1=John R. | last2=Wilson | first2=Joseph B. | last3=Henry | first3=Gregory W. | title=Long-Term VRI Photometry of Small-Amplitude Red Variables. I. Light Curves and Periods | journal=The Publications of the Astronomical Society of the Pacific | volume=113 | issue=786 | pages=983–96 | date=2001 | bibcode=2001PASP..113..983P | doi=10.1086/322153 |doi-access=free }}</ref>

<ref name=AAVSOUX>{{cite web | url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=17933 | title=UX Lyncis | last=Watson | first=Christopher | date=4 January 2010 | publisher=American Association of Variable Star Observers | work=AAVSO Website | access-date=10 March 2016}}</ref>

}}

{{Stars of Lynx}}

Category:M-type giants Category:Semiregular variable stars Category:Lynx (constellation) Category:Durchmusterung objects 077443 044481 Lyncis, UX