Alpha Persei
Encyclopedia
Alpha Persei is the brightest star
in the constellation
of Perseus
, just outshining the constellation's best known star Algol. It also bears the traditional names Mirfak and Algenib. A yellow-white supergiant
, it lies around 590 light years from Earth and is a member of a cluster of stars
known as the Alpha Persei Cluster
.
is 5,000 times and its diameter 62 times that of our Sun. It has a similar spectrum to Procyon
, though the latter star is much less luminous. This difference is highlighted in their spectral designation under the Yerkes spectral classification, published in 1943, where stars are ranked on luminosity as well as spectral typing. Procyon is thus F5 IV.
It lies in the middle of a cluster of stars
known as the Alpha Persei Cluster
, or Melotte 20, which is easily visible in binoculars
and includes many of the fainter stars of Perseus
.
In the Hertzsprung–Russell Diagram
, Mirfak lies very close to the region in which Cepheid variable
s are found. It is thus useful in the study of these stars, which are extremely important standard candles.
when viewed from the latitude of New York
.
in origin. The former, meaning 'Elbow' and also written Mirphak, Marfak or Mirzac, comes from the Arabic Mirfaq al-Thurayya, while Algenib, also spelt Algeneb, Elgenab, Gęnib, Chenib or Alchemb, is derived from الجنب al-janb, or الجانب al-jānib, 'the flank' or 'side'. Gamma Pegasi
also bears the name Algenib.
It forms part of Tien Yuen, the Heavenly Enclosure, in traditional Chinese astronomy
. It is known as 天船三 (Mandarin: tiān chuán sān), the Third Star of the Celestial Boat.
Hinali'i is the name of the star in Native Hawaiian
astronomy
. The name of the star is meant to commemorate a great tsunami
and mark the beginning of the migration of Maui. According to some Hawaiian folklore
, Hinali'i is the point of separation between the earth and the sky that happened during the creation of the Milky Way
.
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
in the constellation
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....
of Perseus
Perseus (constellation)
Perseus is a constellation in the northern sky, named after the Greek hero Perseus. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations defined by the International Astronomical Union...
, just outshining the constellation's best known star Algol. It also bears the traditional names Mirfak and Algenib. A yellow-white supergiant
Supergiant
Supergiants are among the most massive stars. They occupy the top region of the Hertzsprung-Russell diagram. In the Yerkes spectral classification, supergiants are class Ia or Ib . They typically have bolometric absolute magnitudes between -5 and -12...
, it lies around 590 light years from Earth and is a member of a cluster of stars
Star cluster
Star clusters or star clouds are groups of stars. Two types of star clusters can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars which are gravitationally bound, while open clusters, more loosely clustered groups of stars, generally contain less than...
known as the Alpha Persei Cluster
Alpha Persei Cluster
The Alpha Persei Cluster, also known as Melotte 20 or Collinder 39, is an open cluster in the constellation of Perseus. To the naked eye, the cluster consists of several blue spectral type B type stars. The most luminous member is the ~2nd magnitude white-yellow supergiant Mirfak, also known as...
.
Physical properties
With an absolute magnitude of -4.50, its luminosityLuminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...
is 5,000 times and its diameter 62 times that of our Sun. It has a similar spectrum to Procyon
Procyon
Procyon is the brightest star in the constellation Canis Minor. To the naked eye, it appears to be a single star, the seventh brightest in the night sky with a visual apparent magnitude of 0.34...
, though the latter star is much less luminous. This difference is highlighted in their spectral designation under the Yerkes spectral classification, published in 1943, where stars are ranked on luminosity as well as spectral typing. Procyon is thus F5 IV.
It lies in the middle of a cluster of stars
Star cluster
Star clusters or star clouds are groups of stars. Two types of star clusters can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars which are gravitationally bound, while open clusters, more loosely clustered groups of stars, generally contain less than...
known as the Alpha Persei Cluster
Alpha Persei Cluster
The Alpha Persei Cluster, also known as Melotte 20 or Collinder 39, is an open cluster in the constellation of Perseus. To the naked eye, the cluster consists of several blue spectral type B type stars. The most luminous member is the ~2nd magnitude white-yellow supergiant Mirfak, also known as...
, or Melotte 20, which is easily visible in binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
and includes many of the fainter stars of Perseus
Perseus (constellation)
Perseus is a constellation in the northern sky, named after the Greek hero Perseus. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations defined by the International Astronomical Union...
.
In the Hertzsprung–Russell Diagram
Hertzsprung–Russell diagram
The Hertzsprung–Russell diagram is a scatter graph of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their spectral types or classifications and effective temperatures. Hertzsprung–Russell diagrams are not pictures or maps of the locations of the stars...
, Mirfak lies very close to the region in which Cepheid variable
Cepheid variable
A Cepheid is a member of a class of very luminous variable stars. The strong direct relationship between a Cepheid variable's luminosity and pulsation period, secures for Cepheids their status as important standard candles for establishing the Galactic and extragalactic distance scales.Cepheid...
s are found. It is thus useful in the study of these stars, which are extremely important standard candles.
Visibility
A fairly bright star of the second magnitude, Mirfak is circumpolarCircumpolar star
A circumpolar star is a star that, as viewed from a given latitude on Earth, never sets , due to its proximity to one of the celestial poles...
when viewed from the latitude of New York
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
.
Etymology and cultural significance
The names Mirfak and Algenib are ArabicArabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...
in origin. The former, meaning 'Elbow' and also written Mirphak, Marfak or Mirzac, comes from the Arabic Mirfaq al-Thurayya, while Algenib, also spelt Algeneb, Elgenab, Gęnib, Chenib or Alchemb, is derived from الجنب al-janb, or الجانب al-jānib, 'the flank' or 'side'. Gamma Pegasi
Gamma Pegasi
Gamma Pegasi is a star in the constellation of Pegasus. It also has the traditional name Algenib; confusingly however, this name is also used for Alpha Persei....
also bears the name Algenib.
It forms part of Tien Yuen, the Heavenly Enclosure, in traditional Chinese astronomy
Chinese astronomy
Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...
. It is known as 天船三 (Mandarin: tiān chuán sān), the Third Star of the Celestial Boat.
Hinali'i is the name of the star in Native Hawaiian
Native Hawaiians
Native Hawaiians refers to the indigenous Polynesian people of the Hawaiian Islands or their descendants. Native Hawaiians trace their ancestry back to the original Polynesian settlers of Hawaii.According to the U.S...
astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
. The name of the star is meant to commemorate a great tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
and mark the beginning of the migration of Maui. According to some Hawaiian folklore
Folklore in Hawaii
Folklore in Hawaii in modern times is a mixture of various aspects of Hawaiian mythology and various urban legends that have been passed on regarding various places in the Hawaiian islands. The following is a partial list of some of these legends....
, Hinali'i is the point of separation between the earth and the sky that happened during the creation of the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
.