Exomoon
Astronomers use the term exomoon to refer to moons orbiting planets orbiting another star (exoplanet).[1]
As of 2026[update] over 5,000 exoplanets have been detected, but no exomoons have been confirmed.[1][2]
In 2005 it was proposed that an object five times the mass of Planet Jupiter orbited a brown dwarf in the 2M1207 stellar system.[3][4][5]
The HD 206893 system also has a Jupiter sized object orbiting a brown dwarf.[5]
In July 2026 an object was discovered that some commentators called an exomoon.[5] The object, CD 352722 B b, was about 0.9 times the mass of Planet Jupiter. However the discovers called it an "exo-satellite" because it orbited CD-35 2722 B, a brown dwarf, 37 times the mass of Jupiter.
References
[edit | edit source]- ↑ 1.0 1.1
David Kipping (2025-11-20). "JWST Surveyed a Jupiter-like Exoplanet for Exomoons: Results". Cool Worlds. Archived from the original on 2026-03-05. Retrieved 2026-06-26 – via YouTube.
The day has finally come! Today we share our results using JWST to look for exomoon around Kepler-167e... buckle in...
- ↑
"The Moons of Hot-Jupiters". Kyplanet. 2026-01-24. Archived from the original on 2026-01-24. Retrieved 2026-06-26 – via YouTube.
Hot-Jupiters like WASP-12 b are some of the most interesting types of planet. But there's growing evidence that these planets may have exomoons orbiting around them.
- ↑
"Discovery of giant 'exosatellite' challenges our notion of what makes a moon". Physics World. 2026-07-22. Archived from the original on 2026-07-31. Retrieved 2026-08-08.
Planetary mass objects around brown dwarfs have been discovered before. Take the example of 2M1207b, which is an object up to six times more massive than Jupiter orbiting a brown dwarf, discovered in 2005 by the Very Large Telescope. Such objects have not been referred to previously as moons or satellites, so why now?
- ↑
"Yes, it is the Image of an Exoplanet - Astronomers Confirm the First Image of a Planet Outside of Our Solar System". www.eso.org. 2005-04-30. Archived from the original on 2026-08-03. Retrieved 2026-08-08.
An international team of astronomers reports today confirmation of the discovery of a giant planet, approximately five times the mass of Jupiter, that is gravitationally bound to a young brown dwarf. This puts an end to a year long discussion on the nature of this object, which started with the detection of a red object close to the brown dwarf.
- ↑ 5.0 5.1 5.2
David Kipping (2026-08-07). "We Need to Talk About That "First Exomoon" Discovery". Cool Worlds. Archived from the original on 2026-08-08. Retrieved 2026-08-08 – via YouTube.
David Kipping explores the technical and linguistic complexities behind recent claims of discovering a first exomoon. This discussion examines established astronomical classification systems, the criteria for substellar objects, and the challenges inherent in distinguishing between planets and natural satellites in hierarchical star systems.