A 'Chthonian planet' (/
IPA: /, sometimes misspelled 'Cthonian'), is a hypothetical class of celestial objects resulting from the stripping away of a
gas giant's
hydrogen and
helium atmosphere. Such atmospheric stripping is a likely result of close proximity to a
star. The remaining
rocky or
metallic
core would resemble a
terrestrial planet in many respects.
[1]
HD 209458b (Osiris) is an example of a
planet that is in the process of having its atmosphere stripped away, though it is not itself a Chthonian planet nor is it expected to become one in the near future. No known Chthonian planets have yet been discovered.
''Chthonia'' means "of the Earth" in
Greek. The term was coined by Hébrard et al, since the term ''Chthonian'' generally refer to Greek deities from hot infernal underground. There are at least three different Chthonias in
Greek mythology, and they are all closely associated with the
goddess Demeter.
See also
★
Hot Jupiter
★
Hypothetical planet
References
1. Hébrard G., Lecavelier Des Étangs A., Vidal-Madjar A., Désert J.-M., Ferlet R. (2003), ''Evaporation Rate of Hot Jupiters and Formation of Chthonian Planets'', Extrasolar Planets: Today and Tomorrow, ASP Conference Proceedings, Vol. 321, held 30 June - 4 July 2003, Institut d'astrophysique de Paris, France. Edited by Jean-Philippe Beaulieu, Alain Lecavelier des Étangs and Caroline Terquem.