What kind of star is Hadar?
Hadar, catalogued as Beta Centauri (β Cen; name applies to component Aa), appears in the official constellation Centaurus. Its apparent visual magnitude is 0.61 combined, while its estimated distance is approximately 390 light-years. Astronomers classify the object as B1 III principal components. 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 14h 03m 49.4s, Dec −60° 22′ 23″ 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 Hadar
A traditional Arabic-derived name commonly interpreted as “ground” or “soil”; Agena is a historical alternative. The IAU assigns Hadar specifically to β Centauri Aa.
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 Hadar
Find the two exceptionally bright stars east of Crux. Hadar is the bluer Southern Pointer and the one nearer Acrux. Ordinary telescopes do not readily resolve its tight inner pair.
Far-southern; circumpolar south of about 30° S and generally invisible north of about 30° N. 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 Hadar
- Hadar is the second-brightest point in Centaurus and roughly the eleventh-brightest in the night sky.
- It is a triple system with a close pair of massive blue stars and a more distant third component.
- Both principal close components are Beta Cephei-type pulsators.
- Hadar and Alpha Centauri form the Southern Pointers guiding observers toward Crux.
- Its apparent proximity to Alpha Centauri is deceptive: Hadar is vastly farther away.
Sources and further reading
Measurements are rounded for readability. Multiple systems, variable stars and distant supergiants can have component-specific or model-dependent values.