Upsilon Aurigae

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title: "Upsilon Aurigae" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["m-type-giants", "asymptotic-giant-branch-stars", "auriga", "bayer-objects", "bright-star-catalogue-objects", "durchmusterung-objects", "flamsteed-objects", "henry-draper-catalogue-objects", "hipparcos-objects"] description: "Star in the constellation Auriga" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/Upsilon_Aurigae" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Star in the constellation Auriga ::

| name = υ Aurigae | image= |image=Auriga constellation map.svg|alt=|float=center|width=260 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=υ Aurigae |x=414|y=518 | caption = Location of υ Aurigae (circled) | epoch = J2000 | ra = | dec = | appmag_v = 4.74 | constell = Auriga | type = Asymptotic giant branch | class = M0 III | r-i = 1.07 | v-r = | b-v = +1.62 | u-b = +1.93 | variable = Suspected | radial_v = +37.62 | prop_mo_ra = +36.426 | prop_mo_dec = −45.606 | pm_footnote = | parallax = 5.7358 | p_error = 0.2055 | parallax_footnote = | absmag_v = −1.28 | source = | mass = | radius = | luminosity = | temperature = | gravity = | metal_fe = | rotational_velocity = | age_gyr = | names = | Simbad = ups+Aur

Upsilon Aurigae is a single star in the northern constellation of Auriga. Its name is a Bayer designation that is Latinised from υ Aurigae, and abbreviated Upsilon Aur or υ Aur. This star has an apparent visual magnitude of 4.74, which means it is bright enough to be seen with the naked eye. Based upon parallax measurements, this star is approximately 570 ly distant from the Earth. It is drifting further away with a radial velocity of +37 km/s.

This is an evolved red giant star with a stellar classification of M0 III. It is a suspected variable star and is currently on the asymptotic giant branch, which means it is generating energy through the fusion of helium along a shell surrounding a small, inert core of carbon and oxygen. The star is two billion years old with 1.64 times the mass of the Sun and has expanded to 61 times the Sun's radius. It is radiating 1,165 times the Sun's luminosity from its photosphere at an effective temperature of .

References

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References

1. {{cite DR3. 3456177332896378496
2. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory.
3. (June 1999). "Revision and Calibration of MK Luminosity Classes for Cool Giants by HIPPARCOS Parallaxes". The Astrophysical Journal.
4. "* ups Aur".
5. (January 1979). "On the Variability of upsilon Aurigae". Information Bulletin on Variable Stars.
6. Eggen, Olin J.. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::