Sirius A (The Dog Star)
2,385,400 km (1,482,200 mi)
Diameter (2 x 1.7144 solar radii)
The brightest star in the night sky, 8.6 light-years away. Radius: 1.71 times the Sun's, so about 2.39 million km across.
Published
How big is that?
2,385,400 km is 1.7 times the Sun.
Sirius A is the largest of the 39 Cosmic Scale objects, and the largest of the 109 objects across all three SizeItUp games.
Size comparison
To scale, smallest to largest: Sirius A in orange beside the Cosmic Scale objects nearest in size, in teal.
| Object | Size | vs Sirius A |
|---|---|---|
| JupiterThe largest planet, a ball of gas with a storm bigger than Earth. | 142,984 km across | 6% of the size |
| The SunOur star. Measured across its visible surface. | 1,391,400 km across | 58% of the size |
| Sirius A (The Dog Star) | 2,385,400 km across | – |
In other units
| Metres | 2,385,400,000 |
|---|---|
| Kilometres | 2,385,400 |
| Miles | 1,482,000 |
How it's measured
Diameter (2 x 1.7144 solar radii). Peer-reviewed radius, nominal solar radius 695,700 km.
Sources
- arxiv.org: Bond et al. 2017 (ApJ 840, 70): R = 1.7144 +/- 0.0090 solar radii.
Checked against the source on .
Could you have guessed it by eye?
Sirius A is one of the objects in Cosmic Scale, a daily size comparison game: you stretch a shape to the size you think is right beside one you know.