31 Comae Berenices (31 Com) is a

yellow giant A giant star is a star with substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature.Giant star, entry in ''Astronomy Encyclopedia'', ed. Patrick Moore, New York: Oxford University Pre ...

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 ...

Coma Berenices Coma Berenices is an ancient asterism in the northern sky, which has been defined as one of the 88 modern constellations. It is in the direction of the fourth galactic quadrant, between Leo and Boötes, and it is visible in both hemisphere ...

. Its

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 ...

is about 4.9 and slightly variable. It is a rare FK Comae Berenices variable, a

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as ...

that spins rapidly and has large

starspot Starspots are stellar phenomena, so-named by analogy with sunspots. Spots as small as sunspots have not been detected on other stars, as they would cause undetectably small fluctuations in brightness. The commonly observed starspots are in gene ...

s on its surface. It is currently in the

Hertzsprung gap The Hertzsprung Gap is a feature of the Hertzsprung–Russell diagram for a star cluster. It is named after Ejnar Hertzsprung, who first noticed the absence of stars in the region of the Hertzsprung–Russell diagram between A5 and G0 spectral type ...

and its outer envelope has just begun convection. In 1989 it was given as a spectral standard for the class G0IIIp. 31 Com is the

north galactic pole The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way Galaxy, and the fundamental plane parallel to an ap ...

star, and occasionally goes by the informal name Polaris Galacticum Borealis, coined by

Jim Kaler James Bailey "Jim" Kaler (December 29, 1938 — November 26, 2022) was an American astronomer and science writer. After elementary and high-school education in Albany, New York, Kaler earned his A.B. at the University of Michigan in 1960. He atte ...

. In

Chinese astronomy Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twe ...

, 31 Comae Berenices is called 郎將,

Pinyin Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally written in Chinese for ...

: Lángjiāng, meaning ''Captain of the Bodyguards'', because this star is marking itself and stand alone in ''Captain of the Bodyguards'' asterism,

Supreme Palace enclosure Tai Wei Yuan, the Supreme Palace Enclosure (太微垣), is one of the San Yuan or Three enclosures Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials" ( Chinese ''x ...

mansion (see :

Chinese constellation Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials" (Chinese ''xīng guān''). The Chinese asterisms are generally smaller than the constellations of Hellenistic t ...

).Ian Ridpath's Startales - Coma Berenices the Berenice's Hair
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References

{{DEFAULTSORT:31 Comae Berenices Coma Berenices G-type giants Comae Berenices, 31 FK Comae Berenices variables Comae Berenices, LS Durchmusterung objects 111812 062763 4883