Sun
The Sun is the star at the centre of the Solar System.
1,391,000 kmDiameterWorlds apart
Sun vs Sirius A
What are they, and what does the difference actually look like?
Two things. One honest scale.
Meet the pair
What these two things are
Sirius A
Sirius A is the brighter main-sequence star in the Sirius binary system.
2,379,000 kmDiameterSirius A has about 1.71 times the diameter of Sun.
Both marked spans share one linear scale. Artwork keeps its proportions; poses and surface detail are illustrative.
Measurements, assumptions & sources +
Sun
Our star, modelled with the IAU nominal solar radius. “Surface” means the visible photosphere. The core is much hotter; this is not a solid surface.
IAU — nominal solar and planetary conversion constants
The marked diameter is calibrated. Unmeasured illustration details are representative.
Sirius A
A rounded main-sequence star model for the brighter member of Sirius.
Defined examples — our methodology
The marked diameter is calibrated. Unmeasured illustration details are representative.
Change the comparison
Put something else beside it.
Measurement details
Why these numbers?
The visual compares diameter with diameter. The records below preserve each value’s basis and caveats.
Sun
1,391,000 kmDiameter · approximate
Our star, modelled with the IAU nominal solar radius. “Surface” means the visible photosphere. The core is much hotter; this is not a solid surface.
Sirius A
2,379,000 kmDiameter · rounded model
A rounded main-sequence star model for the brighter member of Sirius.
- Comparing
- Diameter ↔ Diameter
- Relative size
- Sirius A is larger on this measurement by a factor of about 1.71. Sirius A's selected measurement is approximately 71% greater than Sun's.
How to read the visual
The labelled spans and stored measurements determine the scale; unmeasured illustration details do not.
- Sun is labelled approximate; treat the displayed value as a comparison anchor rather than false precision.
- Sirius A is labelled rounded model; treat the displayed value as a comparison anchor rather than false precision.
There’s always another scale
Follow your curiosity.
SpaceSun1,391,000 kmThe Sun is the star at the centre of the Solar System.SpaceSirius A2,379,000 kmSirius A is the brighter main-sequence star in the Sirius binary system.
SpaceEarth12,740 kmEarth is the rocky planet on which we live and the third planet from the Sun.
SpaceJupiter139,800 kmJupiter is a giant planet composed mainly of hydrogen and helium, orbiting the Sun beyond the asteroid belt.SpaceNeutron star20 kmA neutron star is the dense remnant core left after a massive star explodes as a supernova, composed mostly of neutrons.
SpaceEarth–Sun distance1 AUThe Earth–Sun distance, or astronomical unit, is the standard measure of separation between Earth and the Sun used in astronomy.Side by side
Another point of view.
