When is the best time to observe 24 Canis Majoris?

24 Canis Majoris is best observed from December through February, with peak visibility during January when it transits around midnight in the Northern Hemisphere.

Where is 24 Canis Majoris located in the sky?

24 Canis Majoris lies in the constellation Canis Major at right ascension 07h 03m and declination -23° 50′.

What telescope do I need to see 24 Canis Majoris?

At magnitude 3.0, 24 Canis Majoris is visible to the naked eye from dark skies, easy in any binoculars.

24 Canis Majoris — Star in Canis Major

Magnitude 3.0^m Star Canis Major (CMa) Visible

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About 24 CMa

Description

24 Canis Majoris (also known as Omicron2 CMa) is a blue supergiant of spectral type B3Iab at magnitude 3.02 in Canis Major. Located roughly 2,800 light-years from Earth, it is one of the most distant naked-eye stars and is intrinsically very luminous — roughly 70,000 times the Sun's luminosity. It is a massive, hot star in an advanced stage of evolution.

Observing Tips

24 CMa lies in the body of Canis Major, southeast of Sirius. It is a blue-white star surrounded by the rich star fields of the winter Milky Way. Best observed from January through March when Canis Major is well-placed in the evening sky. Despite its faintness compared to nearby Sirius, it is easily visible to the naked eye.

History

24 CMa is identified by its Flamsteed number rather than a Bayer designation, as it was not among the brightest stars assigned Greek letters by Johann Bayer. It has no traditional proper name. Its extreme luminosity and distance were not appreciated until modern spectroscopic classification revealed its supergiant nature.

Fun Facts

24 CMa is a supergiant that is inherently far more luminous than Sirius, the brightest star in the sky — if placed at Sirius's distance of 8.6 light-years, it would shine as bright as the quarter Moon. Its great distance is the only reason it appears as a modest 3rd-magnitude star.