Gliese 581

system

Gliese 581 is a red dwarf 20.5 light-years away in Libra that became one of the most famous exoplanet hosts of the 2000s. It has three confirmed planets; two further 'habitable' worlds announced in 2009-2010 (581 d and g) were later shown to be illusions of the star's own activity — a landmark cautionary tale.

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Key facts

Type

Red dwarf (M3V)

Distance

20.55 light-years

Confirmed planets

Science

Classification

Type: Single red-dwarf system
Central star: Gliese 581 — M3V (~3500 K, ~0.30 M☉)

Planets

Confirmed planets: 3 (e, b, c)
Retracted: 581 d and g — shown to be stellar-activity artefacts

Distance

Distance: 20.55 light-years

How we know

Note: Three confirmed planets (e, b, c). The once-celebrated 'habitable' planets 581 d and g proved to be artefacts of stellar activity and are NOT shown — a famous cautionary tale. Real distance 20.55 light-years.

Discovery & history

Name: A catalogue designation (Gliese 581); also the variable star HO Librae.

From 2005 ESO's HARPS built up its planet family; the 2010 'habitable 581 g' claim made headlines before d and g were shown to be activity artefacts — a landmark cautionary tale.

Images

Where to find it — in Libra, the Scales (IAU constellation chart). To the eye it is a single point of light; no telescope has imaged its surface. — IAU / Sky & Telescope, R. Sinnott & R. Fienberg (CC BY 3.0) · Wikimedia Commons

Images from open archives · credit shown per image