GJ 1214

Star

GJ 1214 — a small, cool red dwarf only ~0.18 solar masses, ~48 light-years away in Ophiuchus. Faint and long-lived, it hosts one of the most-studied 'water worlds': the steamy sub-Neptune GJ 1214 b.

Open in 3D viewSee GJ 1214 in the live, interactive 3D map

Key facts

Mass

3.62 × 10²⁹ kg

0.182 M☉

Radius

150,271 km

22% of the Sun's radius

Surface temperature

3,101 K (2828 °C)

Spectral type

M4V (a small red dwarf)

Science

Physical

Mass: 3.62 × 10²⁹ kg · 0.182 M☉
Radius: 150,271 km · 22% of the Sun's radius
Density: 25,467 kg/m³ · 25× water
Spectral type: M4V (a small red dwarf)

Composition

By mass: A cool red dwarf only ~0.18 solar masses, 48 light-years away in Ophiuchus.

Temperature

Surface: 3,101 K (2828 °C)

Radiation & temperature

Luminosity: 1.49 × 10²⁴ W · 0.00389 L☉
Surface temperature: 3,101 K (2828 °C)
Peak wavelength: 934 nm · near-infrared (mostly invisible to the eye)

Discovery & history

Name: A Gliese-Jahreiß catalogue designation.

A nearby red dwarf whose 2009 transiting planet — close, and orbiting a small star — became a prime target for probing sub-Neptune atmospheres.

Images

Where to find it — in Ophiuchus, the Serpent-Bearer (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