Spica A size and scale context

Spica A is the hot blue primary in the Spica binary and a Beta Cephei variable near the end of its main-sequence life. Its rapid rotation and close companion distort the star into an ellipsoidal shape, so the system appears to breathe and shimmer even though the stars remain unresolved to the naked eye. Read its scale context, comparisons, and journey links on the canonical object page.

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Between the smallest and the largest, perspective is everything.

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 turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.

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Solar System Planets From Electron to Atoms Stars To Scale Birth And Death Of Stars Black Holes To Scale

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Planets of the Solar System Stars of the Universe Black holes Subatomic scale

Return to Earth hello@scaleofspace.org

Between the smallest and the largest, perspective is everything.

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 turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.

Editorial

Solar System Planets From Electron to Atoms Stars To Scale Birth And Death Of Stars Black Holes To Scale

Views

Planets of the Solar System Stars of the Universe Black holes Subatomic scale

Return to Earth hello@scaleofspace.org

Stars

Procyon A

Procyon A is the bright F-type primary of the Procyon binary and has begun to swell beyond an ordinary main-sequence star. Its faint companion, Procyon B, is already a white dwarf, so the pair gives astronomers a nearby before-and-after snapshot of stellar evolution in one system.

Scale fact2.84 million kmdiameter

Object class: F-type subgiant star
Mass: ~1.48 solar masses
Host: Procyon system
Estimated age: ~1.9 billion years
Composition: Hydrogen and helium
Temperature: ~6,580 K surface

Stars

Spica A

Scale fact10.4 million kmdiameter

Object class: B-type giant/subgiant star
Mass: ~11.4 solar masses
Host: Spica system
Estimated age: ~12.5 million years
Composition: Hydrogen and helium
Temperature: ~25,300 K surface

Stars

Pollux

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.

Scale fact12.5 million kmdiameter

Object class: Orange giant star
Mass: ~1.9 solar masses
Temperature: ~4,810 K surface
Estimated age: ~0.9–1.7 billion years
Composition: Hydrogen and helium