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.
Open in 3D viewSee Wolf 359 in the live, interactive 3D map
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 (2,527 °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
- Computed from mass and radius
- Spectral type
- M6V (cool red dwarf)
Motion through space
- Proper motion
- 4.72 arcseconds per year · its drift across our sky
- SIMBAD — 2020yCat.1350....0G, 2018MNRAS.475.1960F
- Radial velocity
- +19.6 km/s · moving away from the Sun
- SIMBAD — 2020yCat.1350....0G, 2018MNRAS.475.1960F
- Speed across our line of sight
- 53.8 km/s
- Computed from proper motion and parallax
- Speed through space, relative to the Sun
- 57.3 km/s
- Computed from proper motion, parallax and radial velocity
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 (2,527 °C)
Radiation & temperature
- Luminosity
- 5.36 × 10²³ W · 0.0014 L☉
- Surface temperature
- 2,800 K (2,527 °C)
- Peak wavelength
- 1035 nm · near-infrared (mostly invisible to the eye)
- Computed (Wien's law) from the surface temperature
Discovery & history
- Discovered
- 1917
- By
- Max Wolf
- Method
- Telescope
- 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