Key facts
- Category
- Stars
- Object class
- K-type orange giant star
- Mass
- ~1.9 solar masses
- Temperature
- ~4,810 K surface
- Scale fact
- 12.5 million kmdiameter
- Estimated age
- ~0.9–1.7 billion years
- Composition
- Hydrogen and helium
Pollux
12.5 million kmdiameter
Visual creditscaleofspace.org / CC BY-NC 4.0
Details
Pollux is the brightest star in Gemini and the nearest giant star to the Sun. It has already left the main sequence and swelled into an orange giant, making it a useful nearby preview of what a Sun-like star looks like after exhausting core hydrogen.
Pollux is the nearest giant star to the Sun. After exhausting hydrogen in its core, it expanded to about nine times the Sun’s diameter and now shines as the brightest star in Gemini.
Repeated radial-velocity measurements also reveal a giant planet in orbit around it. The system shows that planets can remain around a star after it leaves the main sequence, although its later expansion changes the environment they occupy.
Links
- Editorial guides
- Universe journey
- Solar neighborhood
- Preset views
- Wikipedia
- Pollux on Wikipedia
Size neighbors
Objects near Pollux on the scale
On the logarithmic size axis, Pollux falls between Spica A and Sagittarius A*. The band uses nearby K-type orange giant star records.
Sources
References for Pollux
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Pollux — Wikipedia
- Visual: scaleofspace.org / CC BY-NC 4.0
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About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.