Physical Size

A scroll-driven journey through the scale of the universe, from subatomic structures to the largest known cosmic systems.

Luhman 16 BT-type brown dwarf star·~152,000 km

Proxima CentauriM-type red dwarf star·215,000 km

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Stars

Luhman 16 B

Luhman 16 B is the cooler T-type member of the nearest known brown-dwarf binary system. It is massive enough to glow from its own heat but too light to sustain ordinary hydrogen fusion, with patchy clouds that make its brightness change as it rotates.

Scale fact~152,000 kmdiameter

Object class: T-type brown dwarf star
Composition: Hydrogen, helium, and molecular clouds
Mass: ~29 Jupiter masses
Host: Luhman 16 binary system

Stars

Proxima Centauri

Proxima Centauri is the nearest known star to the Sun, just over four light-years away. ESA describes it as a flare star prone to dramatic brightening, yet because it burns fuel so slowly it may remain on the main sequence for another four trillion years.

Scale fact215,000 kmdiameter

Object class: M-type red dwarf star
Mass: ~0.12 solar masses
Host: Alpha Centauri system
Estimated age: ~4.8 billion years
Composition: Hydrogen and helium
Temperature: ~3,000 K surface