Bright stars · Canis Major
Sirius
Alpha Canis Majoris
Details
Magnitude
-1.46
Spectral type
A1V
Bayer
Alpha Canis Majoris
Distance
8.6 ly
The brightest star in the night sky — impossible to miss when it is above the horizon.
BeginnerWhat is it?
Sirius is a bluish-white star about 8.6 light-years away, making it one of our closest stellar neighbours. It is intrinsically bright (about 25 times the Sun's luminosity), and its proximity makes it appear brighter still.
What will I see?
Naked eye
The brightest star in the sky. Twinkles vigorously when low on the horizon, sometimes flashing through spectral colours.
Small telescope
A brilliant blue-white point. Its tiny companion Sirius B (a white dwarf) is essentially impossible to see visually in most amateur telescopes because of Sirius A's glare.
Reference imagery from long-exposure photography usually shows far more colour and structure than the human eye can see through a telescope.
Observing tips
- Beginners often mistake low-altitude Sirius for an aircraft because its atmospheric flashing is so dramatic.
- Higher in the sky, the twinkling calms and its true blue-white colour is easy to appreciate.
Interesting facts
- About 8.6 light-years away — one of our closest stars.
- Actually a binary star: Sirius A (main-sequence) and Sirius B (white dwarf).
- Visible from most of the world (declination ~-17°).