The numbers
- Distance
- 8.6light-yearsOne of the closest stars
- Where it is
- In Canis Major
- How bright it looks
- -1.46magnitudeThe lower it is, the brighter
- Its companion
- A white dwarf, 50 years per orbit
To get an idea
It is not the most powerful star there is: it shines so brightly mainly because it is very close to us.
The Moon, Venus and Jupiter are brighter than Sirius, but none of the three is a star.
Fun facts
These are not in the book: there was no room on paper.
That companion is a white dwarf, the leftover heart of a star that has already reached its end.
The two take about fifty years to go all the way around each other.
The name comes from Greek and means glowing or scorching, and it suits the star well.
In many ancient cultures this star was linked to the figure of a dog.
In winter it is easy to find: just follow Orion's Belt downward.
Test yourself
The first question is the one printed under the QR code, with the answer the book did not give. The other four only exist here.
Question 1 of 5★ is the one from your book
Which is the brightest star in the night sky?
Question 2 of 5
Why does Sirius look so bright?
Question 3 of 5
How many stars is it really?
Question 4 of 5
What constellation is it in?
Question 5 of 5
What does its name mean?
Riddles
I am the brightest of my kind and none comes close, and yet I am not the most powerful: what helps me most is that I live nearby. What am I?
I look like one, but we are two: my companion is tiny, burned out and heavy, and we circle each other every half century. What am I?
My ancient name means scorching, and whoever looks at me has always thought of a dog. In winter you find me by following three stars in a row. What am I?
Try it yourself
Look at it when it is low on the horizon: it sparkles with colors, red, green and blue, because its light passes through more air.
Try to check whether it really is the brightest: compare it with every other star you can see that evening. None can match it.
The words
- binary system
- Two stars circling each other, held together by gravity.
Sources: Wikidata (Q3409), Wikipedia (Sirio).