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 A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

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-years 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 surfa ...

. It forms a wide

optical binary In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a ...

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 ...

spectral class In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

M1 and has an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

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 consumed by the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

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 The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...

(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 The red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution. It is a stage that follows the main sequence for low- to intermediate-mass sta ...

. It is about 11.3 billion years since it first formed. It has an effective surface temperature of and a

bolometric luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a ...

of , meaning that its radius is . α Vulpeculae has been suspected to be

variable Variable may refer to: * Variable (computer science), a symbolic name associated with a value and whose associated value may be changed * Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many ...

in brightness by about a tenth of a magnitude, but this has never been confirmed. Analysis of the

isotopic ratio In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the atomi ...

s in its photosphere 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 Pin ...

095771 Durchmusterung objects 7405 183439 Suspected variables TIC objects