Betelgeuse. A captivating red supergiant star in the constellation Orion, primarily located in the southern sky. Positioned at RA 88.7929°, Dec 7.4071°, this star is known for its exceptionally high intrinsic luminosity - a magnitude of 0.45 - making it f

The star’s recognition is primarily tied to the fact that it represents a large and relatively cool red giant star, strikingly different in appearance from typical stars of its type. Its vast size within the Orion constellation – and the specific location within its boundaries - makes it significantly noticeable to the naked eye. It's often distinguished from other stars within its immediate region due to its distinct visual characteristics, particularly its irregular shape. The star has shown substantial variability in brightness over its historical lifecycle, particularly exhibiting powerful flares of extreme energy, as evidenced by observations from the past two and a half centuries.

Given its extended lifespan and ongoing increase in luminosity, Betelgeuses serves as a potent visual demonstration of stellar evolution. It is an example of a red giant entering its final stages of activity, consuming material that it acquired during its earlier, longer, more stable state. The red color is indicative of significant thermal heating to the core of the star. The luminosity observed now – a magnitude of 0.45 - has fueled considerable scientific fascination, pushing researchers to further investigate the physical processes that trigger this transformation, particularly the mechanisms behind its ongoing stellar expansion.

Beyond the sheer spectacle, observing Betelgeuse can evoke a sense of profound time and celestial dynamism. It is a reminder of the grand scale of cosmic history – and the dramatic changes that mark the ongoing lives of even the largest stars.

How to see it

Betelgeuse has a visual magnitude of about 0.45: under a reasonably dark sky it is typically reachable with the unaided eye.

Sky position

Equatorial coordinates for Betelgeuse: right ascension 5h 55m 10s, declination +7° 24′ 25″ (J2000), on the celestial sphere.

Catalog context

Betelgeuse. It appears in classical and modern catalogs as Bayer/Flamsteed designation 58Alp Ori, HIP 27989, HD 39801, Gaia DR3 HYG-HIP-27989.

Catalog identifiers

Gaia

Gaia DR3 HYG-HIP-27989

HIP

27989

HD

39801

gaia_dr3

HYG-HIP-27989

Bayer / Flamsteed

58Alp Ori

Also known as

• 58Alp Ori
• Gaia DR3 TOP 5M HYG-HIP-27989
• HD 39801
• HIP 27989
• HYG-HIP-27989

Observed properties

Visual magnitude

0.45