Night Sky Highlights for January-March 2021
Solar System
Mercury
The best chance to observe Mercury this winter is in late January, especially around the dates of January 23-25, when it will be visible in the southwestern sky just after sunset. There is also a morning appearance in mid-March, but its low angle with the horizon will make it challenging to see.
Venus
In the beginning of January, early risers may be able to spot Venus very low in the southeast just before sunrise. For the rest of the winter, Venus will be too close to the Sun to see.
Mars
The disk of Mars get smaller as it moves away from us, but the planet is still very conspicuous (first magnitude or brighter) throughout the winter. It will be easy to find this red beacon in the south and southwest during the evening hours.
Jupiter
After its close conjunction with Saturn in December, Jupiter will be too close to the Sun in January and February to be easily viewed. By March, it can be seen in the southeastern sky before dawn in the constellation Capricornus.
Saturn
Like Jupiter, Saturn will be too close to the Sun for easy observation in January and most of February. Because Jupiter has now passed Saturn (from our viewpoint), their separation will be slowly increasing as the days and weeks go by. By mid-March Saturn will be about 10 degrees west of Jupiter in the pre-dawn sky.
Uranus
Currently in Aries, Uranus will be well placed for evening observing throughout the winter. Its blue-green disk can be seen with even a small telescope. If you have never looked for it with a telescope it can be a thrill to find it. On January 21, Uranus will be about 1.8 degrees south of brilliant Mars, which should make it easy to locate.
To find Uranus or Neptune with a telescope, you will need a go-to scope or a finder chart such as the one in this article from the Sky & Telescope website:
www.skyandtelescope.com/observing/planets/ice-giants-neptune-and-uranus/
Neptune
Neptune is in Aquarius. In January and early February it can be found in the southwest sky in the early evening. For the rest of the winter it will be too close to the Sun to be seen.
Deep Sky Objects
The Caldwell Catalog is a list of 109 deep sky objects created by Patrick Moore in 1995 to supplement the Messier Catalog. These are all interesting targets for amateur astronomers but they vary greatly in their degree of difficulty. Some are visible to the naked eye, and others are challenging to see even with a good telescope. The objects are listed from north to south, so in Connecticut only about the first 75 or 80 objects are visible. Below are some of the Caldwell objects well placed for winter observation.
Caldwell 1 (NGC 188)
Open cluster in Cepheus
Just 5 degrees from the north celestial pole, this 8th magnitude open cluster is visible all year. It is a very old open cluster, perhaps 9 billion years old, and contains something like 100 stars. Star-hop chart
Caldwell 2 (NGC 40, the Bow Tie Nebula)
Planetary nebula in Cepheus
This is a nice planetary nebula to check out because its 9th magnitude central star is easy to see in even small telescopes. The star is surrounded by a faint nebula with a blue-green tint. In large scopes, two brighter edges of the nebula can be seen, which gives the object its bow tie appearance and its nickname.
Caldwell 5 (IC 342)
Spiral galaxy in Camelopardalis
More than 1/4 degree in diameter, this is a large face-on spiral galaxy that is relatively nearby, about 10 million light years away. However, it is obscured by dust from our Milky Way. It has a fairly bright central region, but the surrounding spiral arms are very faint and not easy to see in a typical amateur telescope.
Caldwell 7 (NGC 2403)
Spiral galaxy in Camelopardalis
This is another fairly nearby spiral, about 8 million light years away. Its oval shape is obvious through a telescope with a low-power eyepiece, but surface detail is pretty hard to see. The galaxy is thought to be a member of a group of galaxies that includes the well-known pair M81 and M82 in Ursa Major.
Caldwell 8 (NGC 559)
Open cluster in Cassiopeia
This cluster is fairly compact, about 7 arcminutes in diameter, and contains about 150 stars. At magnitude 9.5 it is not as bright as some of the other nearby clusters in Cassiopeia, but it is a nice distinct group that makes a good telescopic target.
Caldwell 10 (NGC 663)
Open cluster in Cassiopeia
This cluster contains a nice mixture of brighter and dimmer stars scattered in an area of about 1/4 degree in diameter. It is quite a bit larger and slightly brighter than the open cluster M103. which is about 1.5 degrees away. It is interesting to compare these two clusters, only one of which made it into Messier’s catalog. Star-hop chart
Caldwell 46 (NGC 2261), Hubble’s Variable Nebula
Diffuse nebula in Monoceros
This is a very interesting nebula because its appearance can actually change over as little as a few days. The nebula is fan-shaped and looks a lot like a comet. The brightest section of the nebula contains the variable star R Monoceros. It is thought that moving clouds of dust surrounding R Mon cast shadows on the nebula that change over time.
Caldwell 49 (NGC 2237-9), the Rosette Nebula, and NGC 2244
Diffuse nebula and open cluster in Monoceros
The Rosette Nebula is more than 1 degree in diameter, and it surrounds the open cluster NGC 2244. The star cluster is easy to see in even small telescopes, but the large nebula is so dim and diffuse that it is much more challenging. To spot it, you will need a dark night and a low-power eyepiece with a large field of view.
Caldwell 64 (NGC 2362), the Tau Canis Majoris Cluster
Open cluster in Canis Major
This is a pretty cluster, triangular in shape with sharp points, and very distinct. The cluster includes the bright star Tau Canis Majoris, which increases its visual appeal. It is about 4800 light years away.