Gamma Persei (Gamma Per, γ Persei, γ Per) is a

binary star A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

system 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 first constellati ...

Perseus In Greek mythology, Perseus (, ; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer of ...

. The combined

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

of the pair is +2.9, making it the fourth-brightest member of the constellation. The distance to this system is of roughly with a 1%

margin of error The margin of error is a statistic expressing the amount of random sampling error in the results of a Statistical survey, survey. The larger the margin of error, the less confidence one should have that a poll result would reflect the result of ...

. About 4° to the north of Gamma Persei is the radiance point for the annual Perseid meteor shower. Gamma Persei TESS lightcurve

This is a wide

eclipsing binary A binary star or binary star system is a Star system, system of two stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved ...

system with an orbital period of 5,329.8 days (14.6 years). This eclipse was first observed in 1990 and lasted for two weeks. During an eclipse, the primary passes in front of the secondary, causing the magnitude of the system to decrease by 0.55. The primary component of this system is a

giant star A giant star has a substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature. They lie above the main sequence (luminosity class V in the Yerkes spectral classification) on the Hertzsp ...

with a

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction gratin ...

of G9 III. It has a

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bu ...

of 50.0 km s⁻¹ and a lengthy estimated rotation period of 14.6 years. The classification of the secondary remains tentative, with assignments of A3 V and A2(III). Mass estimates for the two stars remain disparate. Using speckle interferometry, McAlister (1982) obtained mass estimates of for the primary and for the secondary, where is the

mass of the Sun The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies a ...

. He noted that the mass estimate was too high for the given classification of the primary. Martin and Mignard (1998) determined masses for both components based on data from the

Hipparcos ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions and distances of ...

mission: for the primary and for the secondary. They admit that the high inclination of the orbit resulted in a large margin of error. Prieto and Lambert (1999) came up with a mass estimate of for the primary, while Pizzolato and Maggio (2000) obtained . Ling et al. (2001) obtained estimates of for the primary and for the secondary, while Kaler (2001) obtained 2.5 and 1.9, respectively. Diamant ''et al.'' (2023) found masses of for A and B respectively.

Name and etymology

*This star, together with δ Per, ψ Per, σ Per, α Per and η Per, has been called ''the Segment of Perseus''. *In Chinese, (), meaning '' Celestial Boat'', refers to an asterism consisting of γ Persei,

η Persei Eta Persei (η Persei, abbreviated Eta Per, η Per), is a red supergiant in the constellation of Perseus. Parallax measurements by the Gaia spacecraft imply that it is 1,000 is light-years away from Earth. At such distance, interstellar ...

α Persei Alpha Persei ( Latinized from α Persei, abbreviated Alpha Per, α Per), formally named Mirfak (pronounced or ), is the brightest star in the northern constellation of Perseus, outshining the constellation's best-known st ...

ψ Persei Psi Persei (Psi Per, ψ Persei, ψ Per) is a single Be star in the northern constellation of Perseus. It has an apparent visual magnitude of about 4.2, so it is visible to the naked eye at night under suitably dark skies ...

δ Persei Delta Persei (Delta Per, δ Persei, δ Per) is a double star in the northern constellation of Perseus. It has an apparent visual magnitude of 3.01, making it readily visible with the naked eye. Parallax measurements give i ...

48 Persei 48 Persei (also known as c Persei, 48 Per, HR 1273, HIP 19343, or ) is a Be star in the constellation Perseus, approximately the 500th brightest of the visible stars in apparent magnitude. It is "well known for its complex spectrum and ...

μ Persei Mu Persei, Latinised from μ Persei, is a binary star system in the northern constellation of Perseus. It is visible to the naked eye as a point of light with a combined apparent visual magnitude of +4.16. The distance to thi ...

and

HD 27084 HD may refer to: Business * H-D or Harley-Davidson, a motorcycle manufacturer * The Home Depot, NYSE stock symbol: HD Chemistry * Hydrogen deuteride, a diatomic compound of hydrogen and deuterium * Mustard gas Codes * Air Do, formerly H ...

. Consequently, the

Chinese name Chinese may refer to: * Something related to China * Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity **Han Chinese, East Asian ethnic group native to China. **'' Zhonghua minzu'', the supra-ethni ...

for γ Persei itself is (, .)AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日

References

{{DEFAULTSORT:Gamma Persei Persei, Gamma Perseus (constellation) Persei, 23 014328 Eclipsing binaries G-type giants A-type main-sequence stars 0915 018925 Durchmusterung objects