Wolf 359
Star
Wolf 359 — one of the smallest and faintest stars near the Sun, a red dwarf (M6V) just 7.9 light-years away in Leo. At barely a tenth of the Sun's mass and ~0.1% of its light, it is a frequent FLARE star, brightening abruptly as magnetic energy is released. No planets are confirmed.
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Key facts
Mass
2.19 × 10²⁹ kg
0.11 M☉
Radius
111,312 km
16% of the Sun's radius
Surface temperature
2,800 K (2527 °C)
Luminosity
5.36 × 10²³ W
Spectral type
M6V (cool red dwarf)
Science
Physical
- Mass
- 2.19 × 10²⁹ kg · 0.11 M☉
- Radius
- 111,312 km · 16% of the Sun's radius
- Density
- 37,870 kg/m³ · 38× water
- Spectral type
- M6V (cool red dwarf)
Rotation
- Note
- Rotates in only a few days and is strongly magnetically active — the source of its frequent flares.
Composition
- By mass
- A tiny, fully convective ball of hydrogen and helium at only ~2800 K, radiating about 0.1% of the Sun's light — most of it infrared. It flares often, brightening abruptly as tangled magnetic fields release energy.
Temperature
- Surface
- 2,800 K (2527 °C)
Radiation & temperature
- Luminosity
- 5.36 × 10²³ W · 0.0014 L☉
- Surface temperature
- 2,800 K (2527 °C)
- Peak wavelength
- 1035 nm · near-infrared (mostly invisible to the eye)
Discovery & history
- Discovered
- January 1, 1917
- By
- Max Wolf
- Name
- Named for the German astronomer Max Wolf and its number (359) in his proper-motion catalogue. Its variable-star name is CN Leonis.
Catalogued by Max Wolf in 1917 from his photographic proper-motion survey — the 359th entry in his list of fast-moving stars. Too faint to have been noticed earlier, it is now one of the most-studied nearby red dwarfs. Two radial-velocity planet candidates were proposed in 2019 but were never confirmed, so none is shown here.
Images
Images from open archives · credit shown per image