Gamma Virginis (γ Virginis, abbreviated Gamma Vir, γ Vir), officially named Porrima , 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 ...

Virgo Virgo may refer to: Arts and entertainment * Virgo (film), a 1970 Egyptian film * Virgo (character), several Marvel Comics characters * Virgo Asmita, a character in the manga ''Saint Seiya: The Lost Canvas'' * ''Virgo'' (album), by Virgo Four, ...

. It consists of two almost identical

main sequence In astronomy, the main sequence is a classification of stars which appear on plots of stellar color index, color versus absolute magnitude, brightness as a continuous and distinctive band. Stars on this band are known as main-sequence stars or d ...

stars at a distance of about 38

light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

Name

''γ Virginis'' ( Latinised to ''Gamma Virginis'') is the star's

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek alphabet, Greek or Latin letter followed by the genitive case, genitive form of its parent constellation's Latin name. The original list of Bayer design ...

. The traditional name ''Porrima'' derives from

Ancient Rome In modern historiography, ancient Rome is the Roman people, Roman civilisation from the founding of Rome, founding of the Italian city of Rome in the 8th century BC to the Fall of the Western Roman Empire, collapse of the Western Roman Em ...

: Porrima, also known as

Antevorta In ancient Roman religion, Antevorta was a goddess of the future, also known as Porrima or Prorsa (a contracted form of ''Proversa''). She and her sister Postverta (or Postvorta) were described as companions or siblings of the goddess Carmenta, so ...

, was one of the Camenae or

goddess A goddess is a female deity. In some faiths, a sacred female figure holds a central place in religious prayer and worship. For example, Shaktism (one of the three major Hinduism, Hindu sects), holds that the ultimate deity, the source of all re ...

es of

prophecy In religion, mythology, and fiction, a prophecy is a message that has been communicated to a person (typically called a ''prophet'') by a supernatural entity. Prophecies are a feature of many cultures and belief systems and usually contain di ...

. In 2016, the

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

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's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included ''Porrima'' for this star. In the catalogue of stars in the ''Calendarium of Al Achsasi Al Mouakket'', this star was designated ''Laouiyet al Aoua'', which was translated into

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

as ''Angulus Latratoris'', meaning 'the angle of the barker'. This star, along with

Beta Virginis Beta Virginis, a name Latinised from β Virginis, is a star in the equatorial constellation of Virgo. It has the proper name Zavijava (), and, despite its designation 'beta', is the fifth-brightest star in Virgo with an apparent visual ...

(Zavijava),

Eta Virginis Eta Virginis (η Virginis, abbreviated Eta Vir, η Vir) is a triple star system in the zodiac constellation of Virgo. From parallax measurements, it is about from the Sun. It has a combined apparent visual magnitude of 3.89, bright en ...

(Zaniah), Delta Virginis (Minelauva) and Epsilon Virginis (Vindemiatrix), were ''Al ʽAwwāʼ'', the Barker. In Chinese, (), meaning '' Left Wall of Supreme Palace Enclosure'', refers to an asterism consisting of Gamma Virginis,

, Delta Virginis, Epsilon Virginis and

Alpha Comae Berenices Alpha Comae Berenices (α Comae Berenices, abbreviated Alpha Com, α Com) is a binary star in the constellation of Coma Berenices ( Berenice's Hair), away. It consists of two main sequence stars, each a little hotter and more luminous ...

. 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 Gamma Virginis itself is (, .), representing (), meaning ''The First Eastern Minister''. 東上相 (Dōngshǎngxiāng), westernized into ''Shang Seang'' by R. H. Allen and the meaning is "the High Minister of State".

Properties

Gamma Virginis is a

, consisting of two stars of nearly equal

apparent magnitude Apparent magnitude () is a measure of the Irradiance, 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 (astronomy), ...

s 3.65 and 3.56, and of

spectral type 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 ...

F0V. With an

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 168.93 years, it was an easy object for amateur astronomers until the beginning of the 1990s, but in 2011 the smaller apparent distance between the stars requires a larger telescope or special techniques such as

speckle interferometry Speckle imaging comprises a range of high-resolution Astrophotography, astronomical imaging techniques based on the analysis of large numbers of short Exposure (photography), exposures that freeze the variation of Astronomical seeing, atmospheri ...

adaptive optics Adaptive optics (AO) is a technique of precisely deforming a mirror in order to compensate for light distortion. It is used in Astronomy, astronomical telescopes and laser communication systems to remove the effects of Astronomical seeing, atmo ...

or optical

interferometry Interferometry is a technique which uses the ''interference (wave propagation), interference'' of Superposition principle, superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important inves ...

to resolve the individual components. The last time they were at

periapsis An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

was in 1836. The distance became wide enough in 2020 to view with a small telescope. The star system has a combined apparent magnitude of 2.9. The system is 39 light-years away from the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

. Gamma Virginis has been reported to be slightly variable, but this is now considered unlikely. At 2.8 degrees north of the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

, Gamma Virginis it can be

occulted An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks f ...

by the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

and (rarely) by

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

s. In June 2011

Saturn Saturn is the sixth planet from the Sun and the second largest in the Solar System, after Jupiter. It is a gas giant, with an average radius of about 9 times that of Earth. It has an eighth the average density of Earth, but is over 95 tim ...

passed a quarter of a degree south of Porrima. Based upon

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

emissions—an indicator of the strength of the

stellar magnetic field A stellar magnetic field is a magnetic field generated by the motion of conductive plasma inside a star. This motion is created through convection, which is a form of energy transport involving the physical movement of material. A localized mag ...

—this system has an estimated age of 1.14 billion years.

Changes of distance and position angle

This table shows the apparent distance between the two stars and their relative position angle: the first three columns show data predicted from an orbit calculated in 1937, the next two columns show in 2006, the next three columns show observations reported by th
Hanwell Community Observatory

References

{{DEFAULTSORT:Gamma Virginis Virginis, Gamma Binary stars Virginis, 029 Virgo (constellation) F-type main-sequence stars Porrima 061941 4825 6 110379 80 Durchmusterung objects Am stars 0482