Alpha Vulpeculae (α Vulpeculae, abbreviated Alpha Vul, α Vul), officially named Anser , is the brightest

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

in the constellation of

Vulpecula Vulpecula is a faint constellation in the northern sky. Its name is Latin for "little fox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of the Summer Triangle (an ...

. It is approximately 291

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...

. It forms a wide optical binary with 8 Vulpeculae. Alpha Vulpeculae is a

red giant A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...

of spectral class M1 and has an apparent magnitude of +4.4. It has been analyzed as a member of the Arcturus stream, a group of stars with high

proper motion Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more dista ...

and metal-poor properties thought to be the remnants of a small

galaxy A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar Sys ...

consumed by the Milky Way.

Nomenclature

''α Vulpeculae'' ( Latinised to ''Alpha Vulpeculae'') is the system's Bayer designation. It bore the traditional name ''Anser'', derived from when the constellation had the name ''Vulpecula cum Ansere'' 'the little fox with the goose'. In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ''Anser'' for this star on 30 June 2017 and it is now so included in the List of IAU-approved Star Names.

Description

α Vulpeculae has evolved away from the

main sequence In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...

after exhausting its core hydrogen and is now a

, probably on the red giant branch. It is about 11.3 billion years since it first formed. It has an effective surface temperature of and a bolometric luminosity of , meaning that its radius is . α Vulpeculae has been suspected to be variable in brightness by about a tenth of a magnitude, but this has never been confirmed. Analysis of the isotopic ratios in its

photosphere The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...

show that it has a mass less than and has not yet evolved to the asymptotic giant branch and experienced a third dredge up.

References

{{DEFAULTSORT:Alpha Vulpeculae Arcturus moving group Vulpeculae, 06 Vulpecula Vulpeculae, Alpha M-type giants

Anser Anser may refer to: People * Anser (poet), poet of ancient Rome * Anser Farooq, Canadian lawyer Other uses * ANSER, a security and defense analysis group * ''Anser'' (bird), a genus of geese * Anser (putter), a model of golf club made by P ...

095771 Durchmusterung objects 7405 183439 Suspected variables TIC objects