427P/ATLAS

427P/ATLAS is a periodic comet and an active asteroid with a 5.65-year orbit around the Sun. It is the second comet discovered by the Asteroid Terrestrial-impact Last Alert System after 478P/ATLAS.

Orbit

The comet orbits within the main asteroid belt at distances between and from the Sun. Studies of its orbital trajectory revealed that it is highly likely a member of the Theobalda collisional family, a group of asteroids formed from a large, shattered parent body about 7 million years ago. The main-belt comets 455P/PANSTARRS and 483P/PANSTARRS also belong to this group.

Physical characteristics

Like most of the main-belt comets, the observed activity from 427P/ATLAS is driven by the sublimation of water ice on its surface, which its mass loss rate is estimated to be about ~ kg/sec^-1 during its perihelion in 2017.
Photometric observations from the Lisnyky Observatory showed that this comet has some notable instability of color, likely caused by the injection of fresh material to its coma.
Observations from the Hubble Space Telescope in 2019 had determined that its nucleus has an effective radius of km, assuming a geometric albedo of.