TOI-791

Star

TOI-791 — an F-type star about half again the Sun's width and a little under a third more massive, burning some 500 degrees hotter and about three times as bright. It sits roughly 1,100 light-years away in Volans.

Open in 3D viewSee TOI-791 in the live, interactive 3D map

Key facts

Mass

2.55 × 10³⁰ kg

1.28 M☉

Radius

1,025,462 km

1.47× wider than the Sun

Surface temperature

6,294 K (6,021 °C)

Spectral type

Science

Physical

Mass: 2.55 × 10³⁰ kg · 1.28 M☉
Radius: 1,025,462 km · 1.47× wider than the Sun
Density: 564 kg/m³ · 0.56× water; Computed from mass and radius
Spectral type: F7

Motion through space

Proper motion: 0.00975 arcseconds per year · its drift across our sky; SIMBAD — 2020yCat.1350....0G, 2018yCat.1345....0G
Radial velocity: +9.1 km/s · moving away from the Sun; SIMBAD — 2020yCat.1350....0G, 2018yCat.1345....0G
Speed across our line of sight: 15.6 km/s; Computed from proper motion and parallax
Speed through space, relative to the Sun: 18 km/s; Computed from proper motion, parallax and radial velocity

Composition

By mass: A main-sequence F-type star about 1.28 solar masses and 1.47 solar radii, roughly 500 K hotter than the Sun and about three times as luminous. Its metal content is slightly below solar ([Fe/H] ≈ −0.14). Never imaged as anything but a point of light.

Temperature

Surface: 6,294 K (6,021 °C)

Radiation & temperature

Luminosity: 1.18 × 10²⁷ W · 3.07 L☉
Surface temperature: 6,294 K (6,021 °C)
Peak wavelength: 460 nm · blue light; Computed (Wien's law) from the surface temperature

Discovery & history

Method: Telescope
Name: A TESS Object of Interest number (TOI-791), with TIC 306472057 its entry in the TESS Input Catalog; no proper name.

An unremarkable catalogue star until TESS watched it: the spacecraft's photometry caught two planets crossing its face, and the star's own size — measured from its spectrum and its Gaia parallax — is what turned those dips into real planet radii.

Images

Where to find it — in Volans, the Flying Fish (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