28P/Neujmin, also known as Neujmin 1, is a large 21-km in diameter periodic comet that orbits the Sun in 18 years. With a perihelion distance (closest approach to the Sun) of 1.6AU (240millionkm), this comet does not get closer than about 0.571AU (85.4millionkm) from Earth.[1]
Orbital and physical characteristics
The comet nucleus is estimated to be 21.4km (13.3mi) in diameter with a low albedo of 0.025.[1] Since 28P has such a large nucleus, it became brighter than the 20th magnitude in early 2019, roughly 2 years before coming to perihelion. When it came to opposition in May 2020, when it was still 3.5AU (520millionkm) from the Sun, it had an apparent magnitude around 16.9. But during the 2021 perihelion passage the comet was on the opposite side of the Sun as the Earth. The comet is not known for bright outbursts of activity.
.png)
