Vega

Star

Vega - the fifth-brightest star in the night sky, 25 light-years away in Lyra, and one of the most important stars in astronomy: for over a century it defined the zero point of the brightness scale. A hot blue-white A-type star twice the Sun's mass, spinning rapidly, it is ringed by a disk of dust - the first such 'debris disk' ever found, a possible sign of forming planets.

Open in 3D viewSee Vega in the live, interactive 3D map

Key facts

Mass

4.25 × 10³⁰ kg

2.13 M☉

Radius

1,739,250 km

2.5× wider than the Sun

Surface temperature

9,600 K (9,327 °C)

Luminosity

1.54 × 10²⁸ W

Spectral type

A0V (blue-white main-sequence star)

Science

Physical

Mass: 4.25 × 10³⁰ kg · 2.13 M☉
Radius: 1,739,250 km · 2.5× wider than the Sun
Density: 193 kg/m³ · 0.19× water; Computed from mass and radius
Spectral type: A0V (blue-white main-sequence star)

Motion through space

Proper motion: 0.35 arcseconds per year · its drift across our sky; SIMBAD — 2007A&A...474..653V, 2004A&A...420..183A
Radial velocity: -13.5 km/s · approaching the Sun; SIMBAD — 2007A&A...474..653V, 2004A&A...420..183A
Speed across our line of sight: 12.7 km/s; Computed from proper motion and parallax
Speed through space, relative to the Sun: 18.6 km/s; Computed from proper motion, parallax and radial velocity

Rotation

Note: Rotates about once every 16 hours; seen nearly pole-on.

Composition

By mass: A hot blue-white main-sequence star about 2.1 times the Sun's mass and ~40 times its light. It spins rapidly and is viewed nearly pole-on, so it looks hotter and brighter than its average surface.

Temperature

Surface: 9,600 K (9,327 °C)

Radiation & temperature

Luminosity: 1.54 × 10²⁸ W · 40.1 L☉
Surface temperature: 9,600 K (9,327 °C)
Peak wavelength: 302 nm · ultraviolet (invisible to the eye); Computed (Wien's law) from the surface temperature

Discovery & history

Method: Naked-eye star
Name: Its IAU proper name Vega derives from the Arabic an-nasr al-waqi, 'the swooping eagle'. It is Alpha Lyrae, the brightest star of Lyra, the Lyre.

Vega was the first star ever photographed (1850) and the first to have its spectrum recorded. In 1983 the IRAS satellite discovered it radiating excess infrared light - warmth from a surrounding dust disk - launching the study of debris disks around other stars. Vega was Earth's pole star around 12,000 BC and will be again near 13,700 AD.

Images

Real JWST/MIRI mid-infrared image of the debris disk around Vega (ALMA contours, lower right) — the detected dust disk, well over 100 AU across. — NASA/ESA/CSA, K. Su et al. (CC BY 4.0) · Wikimedia Commons

Images from open archives · credit shown per image