Mintaka

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Mintaka A/B/C/D
Diagram showing star positions and boundaries of the Orion constellation and its surroundings
Cercle rouge 100%.svg

Location of δ Orionis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
Right ascension 05h 32m 00.400s[1]
Declination −00° 17′ 56.74″[1]
Apparent magnitude (V) 2.23 (3.2/3.3) / 6.85 / 14.0
Characteristics
Spectral type O9.5 II + B0.5III
U−B color index −1.05
B−V color index −0.22
Variable type Eclipsing binary
Astrometry
Radial velocity (Rv) 16 km/s
Proper motion (μ) RA: 0.64 ± 0.56[1] mas/yr
Dec.: -0.69 ± 0.27[1] mas/yr
Parallax (π) 4.71 ± 0.58[1] mas
Distance approx. 690 ly
(approx. 210 pc)
Absolute magnitude (MV) −4.99
Details
Mintaka A
Mass 20[2] M
Radius 15.8[3] R
Luminosity 90,000[2] L
Surface gravity (log g) 3.5[3] cgs
Temperature 31,802 ± 418[3] K
Age 3–6 Myr
Mintaka B
Mass 20[2] M
Luminosity 90,000[2] L
Temperature 33,000[2] K
Other designations
Mintaka, δ Orionis, 34 Orionis, 88 G. Orionis, HR 1852/1851, BD −00°983, HD 36486/36485, SAO 132220/132221, FK5 206, HIP 25930
Database references
SIMBAD data

Mintaka is a star some 916 light years distant[4] in the constellation Orion. It has a Bayer designation of Delta Orionis (δ Ori) and a Flamsteed designation of 34 Orionis. The name Mintaka comes from منطقة manṭaqa, which means "the belt" in Arabic.[5] Together with Alnitak (Zeta Orionis) and Alnilam (Epsilon Orionis), the three stars make up the belt of Orion, known by many names among ancient cultures. When Orion is close to the meridian, Mintaka is the right-most of the belt's stars as seen by an observer in the Northern Hemisphere facing south.

System[edit]

Mintaka is actually a multiple star at the western end of Orion's belt, with a magnitude 7 star about 52 arcseconds away from the main component and an even fainter star in between. The main component itself is also double, consisting of a class B giant and a smaller but hotter class O. The stars orbit each other every 5.73 days. These two stars are both about 90,000 times as luminous as the Sun with a mass of some 20 solar masses.

Observational history[edit]

Radial velocity measurements taken by Henri-Alexandre Deslandres at Paris Observatory showed that Mintaka had a variable radial velocity and therefore was a spectroscopic binary.[6] His preliminary orbital period estimate of 1.92 days was shown to be incorrect in 1904 when Johannes Franz Hartmann using photographic plates taken at Potsdam Observatory showed that the orbital period was 5.7 days.[7] Hartmann also noticed that the calcium K line at 393.4 nanometres in the stellar spectrum did not share in the periodic displacements of the lines due to orbital motion of the star and theorized that there was a cloud in the line of sight to Mintaka that contained calcium. This was the first detection of the interstellar medium.[7]

Etymology and cultural significance[edit]

Mintaka was also seen by astrologers as a portent of good fortune.[5]

Orion's belt[edit]

Main article: Orion's Belt

The three belt stars were collectively known by many names in many cultures. Arabic terms include Al Nijād 'the Belt', Al Nasak 'the Line', Al Alkāt 'the Golden Grains or Nuts' and, in modern Arabic, Al Mīzān al H•akk 'the Accurate Scale Beam'. In Chinese mythology they were also known as The Weighing Beam.[5] The belt was also the Three Stars mansion (simplified Chinese: 参宿; traditional Chinese: 參宿; pinyin: Shēn Xiù), one of the Twenty-eight mansions of the Chinese constellations. It is one of the western mansions of the White Tiger.

In pre-Christian Scandinavia, the belt was known as Frigg's Distaff (Friggerock) or Freyja's distaff.[8] Similarly Jacob's Staff and Peter's Staff were European biblical derived terms, as were the Three Magi, or the Three Kings. Väinämöinen's Scythe (Kalevala) and Kalevan Sword are terms from Finnish mythology.[5]

The Seri people of northwestern Mexico call the three belt stars Hapj (a name denoting a hunter), which consists of three stars: Hap (mule deer), Haamoja (pronghorn), and Mojet (bighorn sheep). Hap is in the middle and has been shot by the hunter; its blood has dripped onto Tiburón Island.[9]

In Spain and Portugal, this asterism is known as Las Tres Marías or As Três Marias, which stand for The Three Marys in Spanish and Portuguese respectively.

In Christian astromythology, Mintaka is also regarded as the third of the three Magi on their way to Bethlehem (Sirius): Caspar, Melchior, Balthasar.

Namesakes[edit]

The USS Mintaka (AK-94) was a United States Navy Crater-class cargo ship named after the star.

See also[edit]

References[edit]

  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ a b c d e Kaler, James B., "MINTAKA (Delta Orionis)", Stars (University of Illinois), retrieved 2010-02-07 
  3. ^ a b c Underhill, A. B. et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society 189: 601–605, Bibcode:1979MNRAS.189..601U 
  4. ^ Kaler, Jim. "MINTAKA". Retrieved 18 March 2014. 
  5. ^ a b c d Allen, Richard Hinckley (1963) [1899]. Star-names and their meanings. New York, NY: Dover Publications. p. 314. ISBN 1-931559-44-9. 
  6. ^ Deslandres, H. (1900). "Variable velocity in line of sight of delta Orionis. (Notes)". The Observatory 23: 148. Bibcode:1900Obs....23..148D. 
  7. ^ a b Hartmann, J. (1904). "Investigations on the spectrum and orbit of delta Orionis". Astrophysical Journal 19: 268–286. Bibcode:1904ApJ....19..268H. doi:10.1086/141112. 
  8. ^ Schön, Ebbe. (2004). Asa-Tors hammare, Gudar och jättar i tro och tradition. Fält & Hässler, Värnamo. p. 228.
  9. ^ Moser, Mary B.; Stephen A. Marlett (2005). Comcáac quih yaza quih hant ihíip hac: Diccionario seri-español-inglés (in Spanish and English). Hermosillo, Sonora and Mexico City: Universidad de Sonora and Plaza y Valdés Editores. 

External links[edit]

Coordinates: Sky map 05h 32m 00.4s, −00° 17′ 57″