Mintaka (Delta Orionis)
Mintaka (Delta Orionis) is a star in the constellation Orion, magnitude 2.4.
The westernmost star of Orion’s Belt — five suns in one point of light, and proof that space is not empty.
Mintaka, from the Arabic for “belt”, is the westernmost of the three stars of Orion’s Belt. It sits almost exactly on the celestial equator, so it rises almost due east and sets almost due west wherever you are on Earth.
That single point of light holds five stars. At its heart a hot blue giant and a smaller partner whirl around each other every 5.7 days, eclipsing slightly as they go. A third star circles them about every 150 years, and a separate pair keeps company nearby. All five are hotter and heavier than the Sun.
Mintaka made history in 1904. At Potsdam, Johannes Hartmann noticed that one calcium line in its spectrum stood still while the others swayed back and forth with the stars’ orbit. That calcium had to lie in a cloud between us and the star — the first detection of the gas between the stars.
Mintaka (Delta Orionis) is 1,200 light-years away: the light we see from it set off around AD 830, around the time Charlemagne was crowned emperor.
Did you know?
- Many names for the Belt. Arab astronomers called the three belt stars the Belt, the Line, and the Golden Grains; in modern Arabic they are the Accurate Scale Beam, and in Chinese mythology the Weighing Beam.
- Where Shēn began. The Chinese asterism Shēn, the Three Stars, began with the belt alone; Betelgeuse, Bellatrix, Saiph and Rigel were added later. Mintaka is its third star.
The westernmost and faintest of the three stars of Orion’s Belt, a blue-white 2nd-magnitude star almost on the celestial equator. A small telescope shows a 7th-magnitude companion close beside it.
When and where to see it
It is best placed in the evening sky around January, when it crosses the meridian at about 10 pm local time (around midnight in December). It sits on the celestial equator, so it can be seen from almost everywhere on Earth.
At its highest it stands 40° up from 50°N, 55° up from 35°N, 90° up from the equator, 55° up from 35°S.
Facts
- Type
- Star
- Constellation
- Orion
- Designations
- Delta Orionis, δ Ori, 34 Ori, HR 1852, HD 36486, HIP 25930
- Magnitude
- 2.4
- Position
- RA 5h 32.0m, Dec −0° 18′ (J2000)
- Spectral type
- O9.5IINwk
- Colour
- blue-white (B−V -0.39)
- Distance
- 1,200 light-years
- Discovered
- Known since antiquity
Open AstroPilot to see when Mintaka (Delta Orionis) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view.