Chiron-type comet

{{Short description|Family of comets}}

A Chiron-type comet (CTC) is a member of a small family of comets defined as having a semi-major axis larger than that of Jupiter (5.2 AU) and a Tisserand's parameter with respect to Jupiter (TJupiter) of more than 3.

The family is named after its largest and most prominent member 2060 Chiron, officially designated as both a comet (95P/Chiron) and a minor planet of the centaur-class, which blurs the line between the two groups.

There are four numbered comets considered to be classical members of this family: 39P/Oterma, 165P/LINEAR, 166P/NEAT, and 167P/CINEOS.

CTCs are distinct from the Encke-type comets (ETC) and Jupiter-family comets (JFC). Contrary to the Chiron-type comets, JFCs have a TJupiter of less than 3 (typically with a period of less than 20 years), while the ETCs have a semi-major axis smaller than that of Jupiter. Another group, the Halley-type comets (HTC), only have a classical definition, that is a period between 20 and 200 years. Members of the CTC family have a dynamical lifetime of 6.5 million years, much longer than the 50,000 years attributed to the Jupiter-family comets.

References

{{reflist|30em|refs=

{{cite web

|title = NASA PDS: Small Bodies Node – Object Classifications

|url = https://pdssbn.astro.umd.edu/data_other/objclass.shtml

|publisher = NASA PDS –Planetary Data System

|accessdate = 18 July 2019}}

{{cite web

|title = JPL Small-Body Database Browser – Orbit Classification – Chiron-type Comet

|url = https://ssd.jpl.nasa.gov/sbdb_help.cgi?class=CTc

|publisher = Jet Propulsion Laboratory

|accessdate = 18 July 2019}}

{{Cite journal

|first1 = Matthew S. |last1 = Tiscareno

|first2 = Renu |last2 = Malhotra

|date = December 2003

|title = The Dynamics of Known Centaurs

|journal = The Astronomical Journal

|volume = 126

|issue = 6

|pages = 3122–3131

|bibcode = 2003AJ....126.3122T

|doi = 10.1086/379554

|arxiv = astro-ph/0211076

|s2cid = 8177784

}}

}}