The Absolute Cosmos: Scientists detect unusual activity on distant planetary object Centaur
Minor planets whose origin is thought to be in Kuiper Belt in the outer reaches of our solar system are called Centaurs. They sometimes have properties similar to that of comet such as tails and comae or sometimes with that of asteroids.
Generally, Centaurs have unstable orbits as they cross or have crossed the orbits of one or more giant planets. But one Centaur named 514107 Kaʻepaokaʻawela is thought to be in stable (though retrograde) orbit.
Centaurs are poorly understood objects with just only eighteen been found since 1920’s. Detecting any kind of activity on them is highly challenging as they are evasive because of their distant, highly irregular orbits.
Earlier this year, a team of astronomers announced the discovery of activity emerging from Centaur 2014 OG392, a planetary object first found in 2014. It orbits deep between Jupiter and Neptune.
The team is headed by astronomer Colin Chandler from Northern Arizona University’s Astronomy and Planetary Science Ph.D. program.
The team focused on building a database search algorithm to reveal archival images of the Centaur and also a follow up observational campaign.
Based on archival images team tracked down Centaur 2014 OG392 and reported the discovery of unusual activity on it.
Scientists detected a coma up to 400,000 km emerging from Centaur 2014 OG392. It appeared to be sublimating carbon dioxide (CO2) and (or) ammonia (NH3), which is the most likely cause of activity on this and other active Centaurs.
The sublimation process is directly converting Centaur 2014 OG392 from solid to gas- this in turn is causing the flow of a comet like halo.
But this seems a little weird as Centaurs generally orbit way too far from Sun in the outer cold regions of solar system, where we can’t expect to see much sublimation happening.
Based on these findings, 2014 OG392 has been reclassified as the comet and will be called comet C/2014 OG392 (PANSTARRS).