TU Andromedae
{{Short description|Star in the constellation Andromeda}}
{{Starbox begin}}
{{Starbox image
| image = 250px
| caption = The visual band light curve of TU Andromedae, from AAVSO data
}}
{{Starbox observe
| epoch=J2000
| constell=Andromeda
}}
{{Starbox character
| u-b=
| variable=Mira
}}
{{Starbox astrometry
| radial_v=
| prop_mo_ra= {{val|-7.435|0.069}}
| prop_mo_dec= {{val|-3.136|0.057}}
| parallax= 0.9435
| p_error= 0.0623
| absmag_v=
}}
{{Starbox detail
| radius =
| rotational_velocity =
| age_myr =
}}
{{Starbox catalog
| names=HD 2890, HIP 2546, 2MASS J00322275+2601459
}}
{{Starbox reference
| Simbad=TU+And
}}
{{Starbox end}}
TU Andromedae (TU And) is a variable star of the Mira type in the constellation Andromeda. It has a spectral type of M5e and a visual magnitude which varies between extremes of 7.6 and 13.5.
TU Andromedae was discovered on photographs taken by Sergey Nikolayevich Blazhko and Lydia Ceraski in 1907 and 1908. The discovery was announced by Witold Ceraski in 1909.
Like all the stars of this kind, TU And is a cool asymptotic giant branch star, meaning it is fusing hydrogen and helium in concentric shells outside an inert core of carbon and oxygen formed earlier in its life on the horizontal branch. Its period is stable at 316.8 days.
The modelled properties of TU Andromedae at maximum brightness are not in agreement with available models of Mira stars (which work for Mira itself). It is uncertain if the problem is in the measured parameters of the star or in imperfections of the models. It had a mass between 1.15 and {{solar mass|1.4}} when it was on the main sequence but is now less massive.
References
{{reflist |refs=
| last1=Ceraski | first1=W. | title=Une variable nouvelle 2.1909 Andromedae
| journal=Astronomische Nachrichten | date=February 1909 | volume=180 | issue=7 | page=119
| doi=10.1002/asna.19091800707 | bibcode=1909AN....180..119C
| url=https://articles.adsabs.harvard.edu/pdf/1909AN....180..119C | access-date=5 November 2024}}
[http://webviz.u-strasbg.fr/viz-bin/VizieR-S?V*%20TU%20And TU And], database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID [http://cdsarc.u-strasbg.fr/viz-bin/Cat?II/250 II/250] Accessed on line 2009-06-30.
| last1=Høg | first1=E. | last2=Fabricius | first2=C.
| last3=Makarov | first3=V. V. | last4=Urban | first4=S.
| last5=Corbin | first5=T. | last6=Wycoff | first6=G.
| last7=Bastian | first7=U. | last8=Schwekendiek | first8=P.
| last9=Wicenec | first9=A.
| title=The Tycho-2 catalogue of the 2.5 million brightest stars
| journal=Astronomy & Astrophysics
| volume=355 | pages=L27–L30 | year=2000
| bibcode=2000A&A...355L..27H | postscript=. }}
| last1=Hillen | first1=M. | last2=Verhoelst | first2=T.
| last3=Degroote | first3=P. | last4=Acke | first4=B.
| last5=van Winckel | first5=H.
| title=The dynamic atmospheres of Mira stars: comparing the CODEX models to PTI time series of TU Andromedae
| journal=Astronomy & Astrophysics
| volume=538 | year=2012
| pages=L6 | bibcode=2012A&A...538L...6H | postscript=. | doi=10.1051/0004-6361/201118653 | arxiv=1201.5815 | doi-access=free }}
}}
{{Stars of Andromeda}}
{{DEFAULTSORT:TU Andromedae}}