WASP-12

Star

WASP-12 — a yellow-white star a little hotter and larger than the Sun, ~1,390 light-years away in Auriga. Ordinary in itself, it is slowly consuming its own planet, whose tidally-stretched, evaporating form it holds on a doomed, decaying orbit.

Open in 3D viewSee WASP-12 in the live, interactive 3D map

Key facts

Mass

2.64 × 10³⁰ kg

1.32 M☉

Radius

1,175,733 km

1.69× wider than the Sun

Surface temperature

6,265 K (5,992 °C)

Luminosity

1.52 × 10²⁷ W

Spectral type

~F9 (yellow-white dwarf)

Science

Physical

Mass: 2.64 × 10³⁰ kg · 1.32 M☉
Radius: 1,175,733 km · 1.69× wider than the Sun
Density: 387 kg/m³ · 0.39× water; Computed from mass and radius
Spectral type: ~F9 (yellow-white dwarf)

Motion through space

Proper motion: 0.00693 arcseconds per year · its drift across our sky; SIMBAD — 2020yCat.1350....0G, 2018A&A...616A...7S
Radial velocity: +19.0 km/s · moving away from the Sun; SIMBAD — 2020yCat.1350....0G, 2018A&A...616A...7S
Speed across our line of sight: 13.6 km/s; Computed from proper motion and parallax
Speed through space, relative to the Sun: 23.4 km/s; Computed from proper motion, parallax and radial velocity

Rotation

Note: A Sun-like star whose steady light lets transit-timing reveal the planet's orbit measurably shrinking.

Composition

By mass: A yellow-white star a little hotter and larger than the Sun. Ordinary in itself, it holds its planet on a doomed, decaying orbit — tides from the star are stretching and stripping the world apart.

Temperature

Surface: 6,265 K (5,992 °C)

Radiation & temperature

Luminosity: 1.52 × 10²⁷ W · 3.96 L☉
Surface temperature: 6,265 K (5,992 °C)
Peak wavelength: 463 nm · blue light; Computed (Wien's law) from the surface temperature

Discovery & history

Method: Telescope
Name: A WASP-survey catalogue designation; no proper name.

Catalogued by the WASP survey, which saw a giant planet transiting it in 2008. Precise transit timing since has revealed the planet's orbit is measurably shrinking — a rare chance to watch a world spiral toward its star.

Images

Where to find it — in Auriga, the Charioteer (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