Epsilon Orionis

Starbox begin
name=Epsilon Orionis Starbox image


caption=Alnilam lights up NGC 1990.
Photograph by Glen Youman. Starbox observe
epoch=J2000
ra=05^h 36^m 12.8^s
dec=−01° 12′ 06.9″
appmag_v=1.70
constell=Orion Starbox character
class=B0 Iab
b-v=−0.19
u-b=−1.03
variable=Alp Cyg Starbox astrometry
radial_v=25.9
prop_mo_ra=1.49
prop_mo_dec=−1.06
parallax=2.43
p_error=0.91
absmag_v=−6.4 Starbox detail
mass=40
radius=26
luminosity=375,000 | temperature=25,000
metal=?
rotation=~87 km/s
age=4 × 10⁶ Starbox catalog
names=Alnilam, Alnihan, Alnitam, 46 Orionis, HR 1903, BD -01°969, HD 37128, SAO 132346, FK5 210, HIP 26311, TD1 4963. Starbox reference
Simbad=HD+37128

Alnilam is a large blue star in the constellation of Orion. It also has the modern name Epsilon Orionis (ε Ori / ε Orionis). Its Flamsteed designation is 46 Orionis.

It is the 30th brightest star in the sky (the 4th brightest in Orion) and as a blue-white supergiant it is one of the most luminous stars known. Together with Mintaka (Delta Orionis) and Alnitak (Zeta Orionis), the three stars make up the belt of Orion, known by many names across many ancient cultures. Alnilam is the middle star.

It is also one of the 57 stars used in celestial navigation. For middle latitudes, it is at its highest point in the sky around midnight on December 15.

Alnilam's relatively simple spectrum has made it useful for studying the interstellar medium. Within the next million years, this star may turn into a red supergiant and explode as a supernova. It is surrounded by a molecular cloud, NGC 1990, which it brightens to make a reflection nebula. Its stellar winds may reach up to 2000 km/s, causing it to lose mass about 20 million times more rapidly than the Sun.

Other names and history

The name "Alnilam" derives from the Arabic النظام "an-niżām", related to the word نظم "nażm" "string of pearls". Related spellings are "Alnihan" and "Alnitam":Richard Hinckley Allen, "Star-names and their meanings" (1936), p. 314-15.] all three variants are evidently mistakes in transliteration or copy errors.

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. The belt was also the Three Stars mansion (zh-tsp|t=參宿|s=参宿|p=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 [Schön, Ebbe. (2004). "Asa-Tors hammare, Gudar och jättar i tro och tradition". Fält & Hässler, Värnamo. p. 228.] . 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.

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. [cite book |last=Moser |first=Mary B. |coauthors=Stephen A. Marlett |title=Comcáac quih yaza quih hant ihíip hac: Diccionario seri-español-inglés |url=http://lengamer.org/admin/language_folders/seri/user_uploaded_files/links/File/DiccionarioSeri2005.pdf |year=2005 |publisher=Universidad de Sonora and Plaza y Valdés Editores |location=Hermosillo, Sonora and Mexico City|language=Spanish and English]

These stars also allegedly influenced the construction of the Pyramids of Giza.

References

ee also

*Epsilon Orionis in fiction