Astronomy Now - January 2021

Highlights: Comet Atlas buzzes Capella

When: evenings throughout January

What’s special: Any comet is a good comet is a sentiment often expressed by those especially taken
by our icy visitors to the inner Solar System. is month, comet 2020 M3 (ATLAS), another
discovery, back on 27 June 2020, by the Asteroid Terrestrial-Impact Last Alert System (ATLAS)
search program (remember the high hopes for another ATLAS, 2019 Y4, which broke apart in April
2020) is predicted be a ninth- to tenth-magnitude object as it takes a turn around brilliant Capella in
Auriga.

e memory of comet 2020 F3 (NEOWISE), which put on a great naked-eye showing last year, is
still strong. is ATLAS presently doesn’t show any signs of coming close to that spectacle, but any
comet is a good comet.

How to observe: As we welcome in 2021, magnitude +0. 08 Capella (alpha [α] Aurigae) blazes away
at the zenith (directly overhead) at around 10.30pm. If you sweep around half a degree to Capella’s
south-west, you should come across the gaseous glow of 2020 M3 (ATLAS).

At the time of writing (around mid-November) it’s past perihelion (closest to the Sun) and shining
at a peak brightness of around magnitude +8. Images in October showed a greenish coma about 20’
in size and a small tail some 4’ long. On 7 November, it passed close to the mighty Orion Nebula
(M42).

As January progresses, the comet moves northwards past Capella, then curves north-westwards and
nally moves due west to pass around three degrees north of magnitude +1.9 Menkalinan (beta [β]
Aurigae) by the start of the last week of February.

Comet 2020 M3 (ATLAS) sported a 20’ coma on 11 October 2020.

Comet 2020 M3 (ATLAS) is predicted to shine at around magnitude +9 to +10 as it buzzes Capella at the start of the year and then
curves northwards and westwards.

View

Highlights: Comet Atlas buzzes ...

January 2021

Astronomy Now