NASA, ESA, and A. Gáspár and G. Rieke (University of Arizona), Public domainFomalhaut b
also named DagonThe first exoplanet 'photographed' in visible light — now thought to be a cloud of dust
Overview
Fomalhaut b, formally named Dagon, is an expanding dust cloud and former candidate planet observed near the A-type main-sequence star Fomalhaut, approximately 25 light-years away in the constellation of Piscis Austrinus. The object's discovery was initially announced in 2008 and confirmed in 2012 via images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Under the working hypothesis that the object was a planet, it was reported in January 2013 that it had a highly elliptical orbit with a period of 1,700 Earth years. The object was one of those selected by the International Astronomical Union as part of NameExoWorlds, their public process for giving proper names to exoplanets. The process involved public nomination and voting for the new name. In December 2015, the IAU announced the winning name was Dagon.
Source: Wikipedia
Why it matters
- Hubble images from 2004–2006 showed a moving point of light inside Fomalhaut's debris ring, announced in 2008.
- By 2014 the object had faded and expanded; in 2020 astronomers concluded it was debris from a planetesimal collision.
- Still a landmark in direct imaging, and the IAU name Dagon stays on the books.
Discovery & system
- Discovered
- 2008 · imaging
- Host star
- Fomalhaut A
The system
| World | Period | Distance | Radius | Mass | Temp. |
|---|---|---|---|---|---|
| Fomalhaut b | 876.1 yr | 177 AU | — | — | — |
By the numbers
- Orbital period
- 876.1 yr
- Distance from star
- 177 AU26,479 million km
- Eccentricity
- 0.8highly elliptical
- Distance from Earth
- 25.1 ly7.7 pc
Sources
Image: NASA, ESA, and A. Gáspár and G. Rieke (University of Arizona), Public domain · Public domain · image page
Text: Wikipedia (CC BY-SA 4.0). Taglines and highlights are editorial.