Astronomers detect atmosphere on icy object beyond Neptune
Astrônomos identified a thin atmosphere around an icy object orbiting Sol in addition to Netuno. The celestial body, cataloged as (612533) 2002 XV93, has an estimated diameter of around 500 kilometers. The detection occurred through observations during a stellar occultation. The finding was published this Monday in the magazine Nature Astronomy.
The object is in Cinturão of Kuiper, a region of icy bodies far from Sol. Sua’s atmosphere is between 5 million and 10 million times thinner than that of Terra. Ela is also 50 to 100 times more rarefied than Plutão. Cientistas estimate that the gases may include methane, nitrogen or carbon monoxide.
Objeto orbits at a similar distance to Plutão
The (612533) 2002 XV93 completes one lap around the Sol in 247 years. At the time of the observations, it was about 5.5 billion kilometers away from Sol, or 37 astronomical units. The average distance is 39.6 AU, varying between 34.6 AU at the closest point and 44.6 AU at the furthest.
More on this story: Icy planet from the outer reaches of the Solar System reveals unexpected atmosphere
- Corpo is about 500 km in diameter
- Elliptical Trajetória in Cinturão of Kuiper
- Composição likely includes water ice, rock and organic compounds
- Surgiu over 4.5 billion years ago
Pesquisadores used telescopes on Kyoto, Nagano and Fukushima. The stellar occultation technique made it possible to measure changes in the background star’s light. The object passed in front of the star and changed its luminosity in a way that indicated the presence of gases.
Hipóteses explain the origin of the rarefied atmosphere
One possibility is that the atmosphere is long-lasting. Ela could be maintained by cryovolcanism, with gases escaping from the interior through fissures in the surface. Essa activity would involve icy and volatile materials, unlike terrestrial volcanoes with molten rock.
Outra explanation points to a temporary event. Gases could have been released by a collision with a smaller object. If the atmosphere subsides in the coming years, this would reinforce the recent impact hypothesis. Caso persists or varies, internal supply would be more likely.
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The finding changes previous views about small, cold bodies. Até then, it was believed that objects of this size would not be able to retain gases. The detection paves the way for new observations of other trans-Neptunians.
Learn more: Pluto’s atmosphere is collapsing as the planet moves away from the Sun, study finds
Estudo used ground-based telescope network
Astrônomos of Observatório Astronômico Nacional of Japão led the work. Ko Arimatsu, of Observatório of Ishigakijima, is the lead author. The team combined data from professionals and amateurs during the occultation event.
The object does not have an easy popular name. Dentro of the team, was simply called XV93. The official nomenclature follows União Astronômica Internacional rules.
Cinturão of Kuiper houses many icy bodies
The region beyond Netuno holds objects formed at the beginning of Sistema Solar. Plutão was the only known atmosphere until this discovery. The new finding indicates that more small worlds may have internal or external activity.
Future Observações will be able to track variations in the atmosphere of (612533) 2002 XV93. Larger Telescópios and space missions may provide additional details about its composition and evolution.
