WASP-39

Star

WASP-39 — a quiet, Sun-like star a little cooler than the Sun (~0.9 solar masses and radii), ~700 light-years away in Virgo. Unremarkable itself, it hosts the puffed-up hot Saturn whose atmosphere JWST used to make the first clear CO₂ detection at any exoplanet.

Open in 3D viewSee WASP-39 in the live, interactive 3D map

Key facts

Mass

1.82 × 10³⁰ kg

0.913 M☉

Radius

653,262 km

94% of the Sun's radius

Science

Physical

Mass: 1.82 × 10³⁰ kg · 0.913 M☉
Radius: 653,262 km · 94% of the Sun's radius
Density: 1,555 kg/m³ · 1.6× water; Computed from mass and radius

Motion through space

Proper motion: 0.019 arcseconds per year · its drift across our sky; SIMBAD — 2020yCat.1350....0G, 2018A&A...616A...7S
Radial velocity: -58.6 km/s · approaching the Sun; SIMBAD — 2020yCat.1350....0G, 2018A&A...616A...7S
Speed across our line of sight: 19.4 km/s; Computed from proper motion and parallax
Speed through space, relative to the Sun: 61.7 km/s; Computed from proper motion, parallax and radial velocity

Radiation & temperature

Luminosity: 2.75 × 10²⁶ W · 0.719 L☉

Discovery & history

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

Catalogued by the WASP survey, which in 2011 saw a giant planet transiting it; its planet's clear, deep atmosphere later made it a flagship JWST target.

Images

Where to find it — in Virgo, the Maiden (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