Alpha Persei

Alpha Persei
Alpha Persei
Perseus constellation map.svg
Locator Dot2.gif

The red dot shows the location of Mirfak in Perseus.
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 03h 24m 19.4s
Declination +49° 51′ 40″
Apparent magnitude (V) 1.79
Characteristics
Spectral type F5 Ib
U−B color index 0.37
B−V color index 0.48
Variable type ?
Astrometry
Radial velocity (Rv) -2 km/s
Proper motion (μ) RA: 24.11 mas/yr
Dec.: -26.01 mas/yr
Parallax (π) 5.51 ± 0.66 mas
Distance approx. 590 ly
(approx. 180 pc)
Absolute magnitude (MV) -4.50
Details
Mass 11 M
Radius 56 R
Luminosity 5,400 L
Temperature 6,600 K
Metallicity ?
Rotation 18 km/s.
Age ? years
Other designations
Mirfak, Mirphak, Marfak, Algeneb, Algenib, 33 Per, HR 1017, BD +49°917, HD 20902, SAO 38787, FK5 120, HIP 15863.

Alpha Persei (α Per) 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.

Contents

Physical properties

With an absolute magnitude of -4.50, its luminosity 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.[1]

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 variables 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 circumpolar when viewed from the latitude of New York.[2]

Etymology and cultural significance

The names Mirfak and Algenib are Arabic 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'.[2] 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.[2]

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.[3]

Footnotes

  1. ^ Ramanamurthy G (2007). Biographical Dictionary of Great Astronomers. Sura Books. p. 167. ISBN 817478697X. 
  2. ^ a b c Allen, Richard Hinckley (1963). Star Names: Their Lore and Meaning (revised edition). Dover. pp. 332–33. ISBN 0-486-21079-0. 
  3. ^ Malama Maunakea Astronomy

External links


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Alpha Persei — (α Per / α Persei) Données d observation (Époque J2000.0) Ascension droite 03h 24m 19.4s Déclinaison +49° 51′ 40″ Constellation Persée Magnitude apparente …   Wikipédia en Français

  • Alpha Persei Cluster — Observation data (2000.0 epoch) Constellation Perseus …   Wikipedia

  • Alpha Persei — Es fehlen Koordinatenparameter ! Stern Mirfak Auffinden von Mirfak am Himmel Beobachtungsdaten Epoche …   Deutsch Wikipedia

  • Alpha Per — Alpha Persei Alpha Persei (α Per / α Persei) Données d observation (Époque J2000.0) Ascension droite 03h 24m 19.4s Déclinaison +49° 51′ 40″ Constellation Persée Magnitude apparente …   Wikipédia en Français

  • Α Persei — Alpha Persei Alpha Persei (α Per / α Persei) Données d observation (Époque J2000.0) Ascension droite 03h 24m 19.4s Déclinaison +49° 51′ 40″ Constellation Persée Magnitude apparente …   Wikipédia en Français

  • Delta Persei — Données d observation (Époque J2000.0) Ascension droite 03h 42m 55,5s Déclinaison +47° 47′ 15″ Constellation Persée Magnitude apparente 3,01 …   Wikipédia en Français

  • Delta Persei — Stars of Perseus Delta Persei Observation data Epoch J2000.0      Equinox J2 …   Wikipedia

  • Beta Persei — Datenbanklinks zu Algol Stern Algol (β Persei) Beobachtungsdaten Epoche: J2000.0 …   Deutsch Wikipedia

  • Mirphak — Alpha Persei Alpha Persei (α Per / α Persei) Données d observation (Époque J2000.0) Ascension droite 03h 24m 19.4s Déclinaison +49° 51′ 40″ Constellation Persée Magnitude apparente …   Wikipédia en Français

  • Α Per — Alpha Persei Alpha Persei (α Per / α Persei) Données d observation (Époque J2000.0) Ascension droite 03h 24m 19.4s Déclinaison +49° 51′ 40″ Constellation Persée Magnitude apparente …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”