Gliese 317

Star

Gliese 317 - a red dwarf 49.6 light-years away in Pyxis, unusual for hosting not one but two giant planets - a rare find, since giant planets are scarce around low-mass stars. Both were detected from the star's radial-velocity wobble.

Open in 3D viewSee Gliese 317 in the live, interactive 3D map

Key facts

Mass

8.00 × 10²⁹ kg

0.402 M☉

Radius

280,367 km

40% of the Sun's radius

Surface temperature

3,496 K (3,223 °C)

Luminosity

7.88 × 10²⁴ W

Spectral type

M3.5V (red dwarf)

Science

Physical

Mass: 8.00 × 10²⁹ kg · 0.402 M☉
Radius: 280,367 km · 40% of the Sun's radius
Density: 8,661 kg/m³ · 8.7× water; Computed from mass and radius
Spectral type: M3.5V (red dwarf)

Motion through space

Proper motion: 0.928 arcseconds per year · its drift across our sky; SIMBAD — 2020yCat.1350....0G, 2018MNRAS.475.1960F
Radial velocity: +87.9 km/s · moving away from the Sun; SIMBAD — 2020yCat.1350....0G, 2018MNRAS.475.1960F
Speed across our line of sight: 66.8 km/s; Computed from proper motion and parallax
Speed through space, relative to the Sun: 110 km/s; Computed from proper motion, parallax and radial velocity

Rotation

Note: A quiet red dwarf whose slow, long-period wobble revealed two giant planets over years of monitoring.

Composition

By mass: A hydrogen/helium red dwarf about 0.40 solar mass and ~2% of the Sun's light, 49.6 light-years away in Pyxis. It is unusual for hosting two giant planets — giants are scarce around low-mass stars.

Temperature

Surface: 3,496 K (3,223 °C)

Radiation & temperature

Luminosity: 7.88 × 10²⁴ W · 0.0206 L☉
Surface temperature: 3,496 K (3,223 °C)
Peak wavelength: 829 nm · near-infrared (mostly invisible to the eye); Computed (Wien's law) from the surface temperature

Discovery & history

Method: Telescope
Name: A catalogue designation (Gliese 317); the star has no proper name.

A giant planet was found around this nearby red dwarf in 2007 from radial-velocity monitoring; a second, more distant giant was confirmed in 2016 as the star's slow wobble was tracked over more years.

Images

Where to find it — in Pyxis, the Compass (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