What kind of star is Betelgeuse?
Betelgeuse, catalogued as Alpha Orionis (α Ori), appears in the official constellation Orion. Its apparent visual magnitude is variable, commonly about 0.0–1.6, while its estimated distance is roughly 550–650 light-years. Astronomers classify the object as M1–M2 Ia–ab. These labels describe temperature, luminosity class or system components; they should not be read as a claim that every naked-eye point is a single isolated star.
The coordinate pair RA 05h 55m 10.31s, Dec +07° 24′ 25.4″ fixes the object’s direction on the celestial sphere for the J2000 reference epoch. Right ascension works like celestial longitude measured in hours, while declination works like latitude north or south of the celestial equator. Proper motion and improved measurements can refine catalogue positions, but these coordinates are sufficiently precise for a finder chart or planetarium search.
The name Betelgeuse
Transmitted through Arabic Yad al-Jawzāʾ, “hand of al-Jawza.” It marks Orion’s shoulder; the initial consonant changed through manuscript transmission.
Modern professional catalogues retain identifiers such as the Bayer designation alongside a proper name. The International Astronomical Union standardizes which name belongs to which component—an important distinction for systems whose combined light looks like one star from Earth.
How to find Betelgeuse
Find the orange-red shoulder above Orion’s Belt and compare it with blue-white Rigel. Repeated naked-eye estimates against nearby stars can reveal its real variability over weeks and months.
Visible from almost all inhabited latitudes; best during northern winter and southern summer. Visibility on a particular night still depends on latitude, season, time, horizon obstructions, weather and local light pollution. Use the interactive atlas below to check the surrounding field before observing.
Interesting facts about Betelgeuse
- Betelgeuse is a red supergiant with a photosphere large enough to engulf the inner planets if placed at the Sun.
- Modern interferometers and radio arrays resolve its surface and extended atmosphere.
- The 2019–2020 Great Dimming was linked to surface cooling and dust formation after an outburst, not an imminent explosion.
- Pulsation, convection and changing surface structures make it semiregularly variable.
- It will eventually undergo core-collapse supernova, but astronomy cannot assign a human-calendar date; estimates allow up to around 100,000 years.
Sources and further reading
Measurements are rounded for readability. Multiple systems, variable stars and distant supergiants can have component-specific or model-dependent values.