Vega debris disk
The Vega debris disk - a broad ring of dust orbiting Vega, seen nearly face-on because we look almost down the star's pole. Discovered in 1983 as the first debris disk around any star, it is dust continually ground from unseen comets and asteroids, extending from tens to ~200 AU. Its structure hints at, but has not confirmed, shepherding planets.
Science
Classification
- Type
- Collisional debris disk (a dust ring)
- What it is
- Rocky and icy debris left over from planet formation, ground to dust by collisions among unseen comets and asteroids — NOT a gas/protoplanetary disk
- Analogue
- The Solar System's Kuiper Belt and asteroid belt
What a debris disk tells us
- Collisional cascade
- Starlight removes small dust grains quickly, so the dust we see must be freshly made — evidence of colliding planetesimals we cannot see directly
- Hidden planets
- Sharp edges, gaps or narrow rings are often shepherded by the gravity of an unseen planet — a clue to worlds not yet detected
How we know
- Note
- Debris disks are real, detected structures — first from the infrared 'excess' their dust radiates, and directly imaged in sub-millimetre light where resolved. Fine structure is often model-based rather than directly pictured; this card shows the established belt, never fabricated detail.
Discovery & history
- Discovered
- January 1, 1983
- By
- H. H. Aumann (IRAS)
- Method
- Infrared excess (space telescope)
- Name
- Not a formally named object - the debris disk of Vega (Alpha Lyrae).
In 1983 the IRAS infrared satellite found Vega glowing with far more infrared light than its surface could produce - heat from a surrounding disk of dust (Aumann et al.). It was the first debris disk discovered, and gave its name to the 'Vega phenomenon'. Later sub-millimetre and Spitzer/Herschel/JWST imaging traced a broad, smooth disk out to roughly 200 AU.
Images
Images from open archives · credit shown per image