Betelgeuse
Betelgeuse is a red supergiant star in the constellation Orion that changes in brightness over time.
How big is it?
6.511 AU across
Diameter · rounded model
A little perspective
Neptune’s orbital distance is about 4.62 times larger on this measurement.
Neptune’s orbital distance: Neptune’s orbital distance is the average separation between Neptune and the Sun.
Measurements, assumptions & sources +
Betelgeuse
A deliberately rounded red-supergiant model. Its apparent edge varies with wavelength and the star changes over time.
Defined examples — our methodology
The marked diameter is calibrated. Unmeasured illustration details are representative.
Neptune’s orbital distance
A rounded 30.11 AU semi-major-axis reference, not today’s distance.
Defined examples — our methodology
The marked distance is calibrated. Unmeasured illustration details are representative.
Change your perspective
Put it next to…
Choose a suggestion to redraw the comparison, or open its page to learn what it is.
Why this measurement?
Why we use 6.511 AU
For comparison, this page uses diameter. This is labelled rounded model: an explicit comparison model rather than a claim that every example has the same value.
A deliberately rounded red-supergiant model. Its apparent edge varies with wavelength and the star changes over time.
The marked horizontal span follows the named feature; transparent margins and unmeasured details do not alter it. How calibrated comparisons work →
Recorded properties
Betelgeuse dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 6.511 AU | Not recorded | rounded model | |
| 15 M☉ | Not recorded | rounded model |
Around this scale
Go smaller. Go bigger.
These links use compatible length records, ordered around the selected value.
Nearest lower value · SpaceEarth–Sun distance1 AUThe Earth–Sun distance, or astronomical unit, is the standard measure of separation between Earth and the Sun used in astronomy.Nearest higher value · SpaceNeptune’s orbital distance30.11 AUNeptune’s orbital distance is the average separation between Neptune and the Sun.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
More ways to see it
Curated comparisons
There’s always another scale
Follow your curiosity.
SpaceSun1,391,000 kmThe Sun is the star at the centre of the Solar System.
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.SpaceNeptune’s orbital distance30.11 AUNeptune’s orbital distance is the average separation between Neptune and the Sun.SpaceEarth–Sun distance1 AUThe Earth–Sun distance, or astronomical unit, is the standard measure of separation between Earth and the Sun used in astronomy.
SpaceRed giant0.465 AUA red giant is a star that has expanded and cooled after exhausting the hydrogen in its core.
SpaceKuiper Belt outer orbit50 AUThe Kuiper Belt is a region of the Solar System beyond Neptune containing many icy bodies and dwarf planets.
SpacePlanetary Solar System60.22 AUThe Solar System is the collection of the Sun and all objects gravitationally bound to it, including planets, moons, and smaller bodies.