Eta Boötis
Encyclopedia
Eta Boötis is a star in the constellation
Boötes
. It has the traditional names Muphrid and Saak, and the Flamsteed designation
8 Boötis.
The name Muphrid is from the Arabic مفرد الرامح mufrid ar-rāmiħ "the (single) one of the lancer". In Chinese
, , meaning "the Right Conductor
", refers to an asterism
consisting of Eta Boötis, Tau Boötis
and Upsilon Boötis. Consequently, Eta Boötis itself is known as
In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket
, this star was designated Ramih al Ramih (رمح حالرامح - rumḥ al rāmiḥ), which was translated into Latin
as Lancea Lanceator, possibly meaning the lance of the lancer.
Based on its spectra, Eta Boötis has a significant excess of elements heavier than hydrogen
. In fact the ratio of iron
to hydrogen is considered close to the upper limit for dwarf star
s in the galactic disk. The star has also been identified as a spectroscopic binary with a period of 494 days, but the companion has not been resolved through speckle interferometry.
Eta Boötis appears close to the prominent star Arcturus (Alpha Bootis) in Earth's sky, and Arcturus is in fact its closest stellar neighbor, as both stars are nearly identical in distance from the Sun. The two stars are about 3.24 light years apart http://www.stellar-database.com/Scripts/find_neighbors.exe?ID=96000&ly=15, and each would appear bright in the other's sky. Arcturus would appear as roughly magnitude -5.2 (about 120 times brighter than it appears from Earth, or close to twice the brightness of Venus) in the night sky of a hypothetical planet orbiting Eta Boötis, while Eta Boötis would appear at about magnitude -2.5 in the sky of a hypothetical planet orbiting Arcturus, or over twice the brightness of Sirius in our night sky.
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Boötes
Boötes
Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning herdsman or plowman...
. It has the traditional names Muphrid and Saak, and the Flamsteed designation
Flamsteed designation
Flamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek letters. Each star is assigned a number and the Latin genitive of the constellation it lies in...
8 Boötis.
The name Muphrid is from the Arabic مفرد الرامح mufrid ar-rāmiħ "the (single) one of the lancer". In Chinese
Chinese language
The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...
, , meaning "the Right Conductor
Neck (Chinese constellation)
The Neck mansion is one of the Twenty-eight mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon.In Chinese Cosmology, the Kang Constellation is associated with the Kidney Organ...
", refers to an asterism
Asterism
Asterism may refer to:* Asterism , a pattern of stars* Asterism , an optical phenomenon in gemstones* Asterism , a moderately rare typographical symbol denoting a break in passages...
consisting of Eta Boötis, Tau Boötis
Tau Boötis
Tau Boötis is a yellow-white dwarf approximately 51 light-years away in the constellation of Boötes. The system is also a binary star system, with the secondary star being a red dwarf...
and Upsilon Boötis. Consequently, Eta Boötis itself is known as
In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket
Al Achsasi al Mouakket
Mohammad Al Achsasi Al Mouakket was an Egyptian astronomer whose calendarium and catalogue of stars, entitled Durret al Muddiah Fih al Aamal al Shamsiah , was written at Cairo about 1650.Al Achsasi was sheikh of the Grand Mosque of the University of Cairo, where his name al...
, this star was designated Ramih al Ramih (رمح حالرامح - rumḥ al rāmiḥ), which was translated into Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
as Lancea Lanceator, possibly meaning the lance of the lancer.
Based on its spectra, Eta Boötis has a significant excess of elements heavier than hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
. In fact the ratio of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
to hydrogen is considered close to the upper limit for dwarf star
Dwarf star
The term dwarf star refers to a variety of distinct classes of stars.* Dwarf star alone generally refers to any main sequence star, a star of luminosity class V.** Red dwarfs are low-mass main sequence stars....
s in the galactic disk. The star has also been identified as a spectroscopic binary with a period of 494 days, but the companion has not been resolved through speckle interferometry.
Eta Boötis appears close to the prominent star Arcturus (Alpha Bootis) in Earth's sky, and Arcturus is in fact its closest stellar neighbor, as both stars are nearly identical in distance from the Sun. The two stars are about 3.24 light years apart http://www.stellar-database.com/Scripts/find_neighbors.exe?ID=96000&ly=15, and each would appear bright in the other's sky. Arcturus would appear as roughly magnitude -5.2 (about 120 times brighter than it appears from Earth, or close to twice the brightness of Venus) in the night sky of a hypothetical planet orbiting Eta Boötis, while Eta Boötis would appear at about magnitude -2.5 in the sky of a hypothetical planet orbiting Arcturus, or over twice the brightness of Sirius in our night sky.