Night Sky Highlights for October-December 2021
Solar System
Lunar Eclipse
Morning of Friday, November 19
This is a partial eclipse, but it will be almost like a full total eclipse because at maximum, 97% of the Moon will be covered by the Earth’s shadow. From Connecticut, the entire umbral period (when the darker shadow of the Earth covers parts of the Moon) will be visible in the early morning hours before the Moon sets.
Here are the key times (EST):
1:02 am Penumbral phase begins
2:18 am Umbral phase begins
4:03 am Maximum eclipse
5:47 am Umbral phase ends
6:53 am Moon sets
7:04 am Penumbral phase ends
Mercury
Fast-moving Mercury will be visible low in the east before sunrise in the second half of October, and then in the western sky after sunset in the last week of December. During that evening appearance, it will be close to the very bright Venus, which can help you locate the much dimmer Mercury.
Venus
Throughout the fall, this brilliant planet will be visible low in the west and southwest shortly after sunset. Through a telescope, the planet will appear oval and later about half-lit as its phases change during its orbit around the Sun.
Mars
The red planet will be too close to the Sun to observe in October and November. In December, it starts to rise in the eastern sky before dawn. Don’t confuse it with the red Antares, which will be nearby. Antares (magnitude 1.1) will be brighter than Mars (magnitude 1.6). Through a telescope, the disk of Mars will be tiny (3.8 arcseconds in diameter).
The four gas giants of our solar system will all be visible in the evening skies through most of the fall season:
Jupiter
Throughout the fall, Jupiter will be the brightest object in the sky other than Venus. It’s surface features and four Galilean moons are always a treat to observe with any telescope. The moons are even visible with ordinary binoculars if you hold them steady or put them on a tripod.
Saturn
Saturn is in Capricornus, about 20 degrees to the west of Jupiter. It will be very conspicuous at about magnitude 0.6, but it gets lower in the west and more difficult to observe as we enter December. Besides enjoying the sight of its beautiful rings, see how many of Saturn’s moons you can spot with a telescope at high power.
Uranus
Uranus is in Aries, reaching opposition (rising just as the Sun sets) on November 5. This means that in October it will be rising a few hours after sunset, but in November and December it will be high enough to observe as soon as it gets completely dark. At about magnitude 5.7, this planet is easy to spot with binoculars if you know exactly where to look. See the link below Neptune for a finder chart.
Neptune
Neptune (magnitude 7.9) is in Aquarius, and it will be visible during the evening throughout the fall. To find it, 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/
Deep Sky Objects
The fall evenings bring deep-sky objects many of us know well, such as the Andromeda Galaxy and the Pleiades. But there are also many less familiar targets in the fall that offer very interesting views and a lot of variety. Here is a sample of some easy targets and some more challenging ones. Each object has a link to a star-hop chart to help you find it.
NGC 147 and 185 (Caldwell 17 and 18)
Elliptical galaxies in Cassiopeia
Although they are found within the constellation boundaries of Cassiopeia, these elliptical galaxies are actually satellites of Messier 31, the Andromeda Galaxy. Like M31, they are slightly more than 2 million light years away. They are large and diffuse so you need a good dark night to see them with a medium or large scope. Star-hop chart
NGC 7789, Caroline’s Rose
Open cluster in Cassiopeia
This is a real beauty, a very rich cluster of some 900 stars that was discovered by Caroline Herschel in 1783 and is now named for her. It has many curving strings of stars that give the impression of the petals of a rose. At magnitude 6.7, it is a fine target for any telescope. Star-hop chart
NGC 752 (Caldwell 28)
Open cluster in Andromeda
This is a bright group of 80 or 90 stars covering almost a full degree of sky. It is relatively close, at a distance of about 1200 light years. Because of its large size it is a good target for binoculars or a telescope with a wide-field eyepiece. Star-hop chart
NGC 891 (Caldwell 23)
Spiral galaxy in Andromeda
This spiral galaxy is almost exactly edge-on, making it an interesting sight for observers. It has a dust lane right down the middle that is obvious in photographs but harder to see through the eyepiece. Medium to large amateur scopes will show the dust lane under dark skies. The galaxy is about 27 million light years away. Star-hop chart
NGC 7662 (Caldwell 22), Blue Snowball
Planetary Nebula in Andromeda
The Blue Snowball is listed at magnitude of 8.3 and has a high surface brightness, so its small bluish disk is easy to spot with even small telescopes. Through medium to large telescopes, some surface details can be seen. With a dark center surrounded by a brighter oval ring, it is said to resemble an eye. Star-hop chart
NGC 7009 (Caldwell 55), Saturn Nebula
Planetary nebula in Aquarius
The Saturn Nebula is another small but bright planetary nebula, about magnitude 7.8. If you view it carefully with medium to high magnification, you will understand its nickname. It has two faint extensions on opposite sides of its blue-green center that resemble the rings of Saturn. Messier 73 is less than 2 degrees to its southwest. Star-hop chart
NGC 7293 (Caldwell 63), Helix Nebula
Planetary nebula in Aquarius
The Helix is the closest (520 light years) and largest (about 12′ x 10′) planetary nebula in our sky, yet it is an observing challenge because of its very low surface brightness. It has been seen in 10×50 binoculars, and it is visible in small telescopes at low power. Try looking for it on a nice clear dark night. First look for a hazy glow; then see if you can see the darker center. If you have a nebula filter, it can really help. Star-hop chart
Messier 72 and 73
Globular cluster and asterism in Aquarius
Messier 72 is a distant globular cluster, about 55,000 light years away. It is bright enough to be seen as a hazy ball in small scopes, but a large aperture is needed to resolve any individual stars. About 1.5 degrees east of M72 is M73. This object is definitely not a spectacular sight, but we can give it four stars because that is exactly what it is, a small asterism of four stars in a Y shape. Messier included it in his catalog because he thought the group was engulfed in a faint nebulosity (it is not). Star-hop chart
NGC 7814 (Caldwell 43), Little Sombrero Galaxy
Spiral galaxy in Pegasus
This galaxy has two dim arms extending from a large and bright central bulge, and it is similar in shape to M104, the Sombrero Galaxy. Photographs show a thin dust lane cutting right through the middle of this edge-on galaxy, but don’t expect to see the dust lane through the eyepiece. Star-hop chart
Messier 30
Globular cluster in Capricornus
This is a small but bright globular cluster that is definitely worth checking out. At magnitude 7, it is easy to spot and has a dense center. Through a medium-sized telescope, many individual stars in its periphery can be resolved. Also look for two chains of stars streaming to the north. Star-hop chart