Night Sky Highlights for October-December 2016
Solar System
Meteor Showers
Several meteor showers are visible in the fall each year. A few of the most notable are:
Orionids, peaking on October 21
Leonids, peaking on November 17
Geminids, peaking on December 14
Unfortunately, a bright Moon interferes with the Leonids and Geminids this year. Probably the best bet is to look for some Orionids during the late evenings on or after October 21, before the last-quarter Moon rises.
Mercury
In mid-December, Mercury makes a brief appearance in the western sky right after sunset. It will be furthest from the Sun, and therefore easiest to see, on December 10. Just a week or so later, it will be too close to the Sun to be seen.
Venus
Venus will be fairly low in the western sky after sunset in October, gradually getting higher in November and December.
Mars
Mars will be moving east through Scorpius and Sagittarius even as these constellations move toward the western sunset. As a result, Mars will continue to be visible in the southeast throughout the fall, though iit will not be very large or impressive through a telescope.
Jupiter
The giant planet is close to the Sun in the beginning of October, but by the end of the month it rises in the east shortly before sunrise. It gets higher and higher in the predawn sky in November and December.
Saturn
Saturn has been a treat to observe all summer, and it can still be seen in the early fall, though it will be setting earlier in the evening as the weeks go by. Though a telescope of moderate size, several of its moons should also be visible.
Uranus and Neptune
These two giant planets are not hard to observe with a small telescope, as long as you know where to look. Both are visible throughout the fall. Uranus is in Pisces, and Neptune is in Aquarius. Both have a distinct blue-green color that helps to pick them out of the starry background. This article from the Sky & Telescope website includes finder charts for finding these planets:
www.skyandtelescope.com/observing/planets/ice-giants-neptune-and-uranus/
Pluto
For a more challenging target in you have a telescope with medium or large aperture, try finding Pluto, which is in the “teaspoon” asterism of Sagittarius and can be seen in the southwest during the early fall. Below is a link to a good finder chart from Blue Water Astronomy. The way to be sure you have seen Pluto is to draw what you see on one night and then again on the next night to see if is has moved.
http://www.bluewaterastronomy.info/resources/MapsCharts/Pluto-2016.jpg
Deep Sky Objects
Epsilon Lyra
Double-double star in Lyra
Without optical aide, people with very good eyesight can detect that Epsilon Lyra is a double star. Through binoculars, two blue-white stars can be seen. Through a telescope with high magnification, each can be separated into a close pair of stars.
Perseus Double Cluster
Pair of open clusters in Perseus
This is one of the most frequently observed objects in the fall skies. With the naked eye, these two clusters appear as a faint oblong cloud. With binoculars, two star groupings can be seen. Through a telescope, hundreds of stars are visible, and the view can be spectacular.
Messier 76, the Little Dumbbell Nebula
Planetary nebula in Perseus
The nickname of this nebula suggests that it resembles, in miniature, the larger Dumbbell Nebula (M27). At about magnitude 10, the Little Dumbbell is harder to see, but it does have an oblong shape and a narrow “waist”. It is a nice example of a planetary nebula.
Messier 31, the Andromeda Galaxy (with M32 and M110)
Spiral galaxy in Andromeda
Another favorite in the fall sky, this galaxy can be seen with the naked eye on a dark clear night. Through a telescope, its two largest satellite galaxies (M32 and M110) can also be seen. Once you figure out the directions in your telescope’s eyepiece, start from the nucleus of M31 and then look about ½ degree south for the tight oval glow of M32, and look about 1 degree to the northwest for the larger but dimmer M110.
Messier 103
Open cluster in Cassiopeia
This is a small but distinct open cluster with a triangular shape. It is easy to find, less than 1 degree northeast of delta Cassiopeia, the star that forms the first angle of the “W” shape.
NGC 7789, Caroline’s Rose
Open cluster in Cassiopeia
In contrast to the relatively sparse M103, this cluster contains some 900 stars over an area of about 20 arcminutes (large enough to fill the field of view with a medium power eyepiece). It was discovered by Caroline Herschel in 1783. Look for the swirling strings of stars that look like the petals of a rose.
Eta Cassiopeia
Double star in Cassiopeia
These two stars are of uneven brightness (magnitudes 3.4 and 7.5), but with a separation of about 12 arcseconds they can be easily resolved in just about any telescope. Their colors have been described as gold and purple. What colors do you see?
Messier 2
Globular cluster in Aquarius
At about magnitude 6, this is one of the brightest globular clusters in the sky, and it does not get the attention it deserves. It is a fairly dense globular that is not as easily resolved into stars as the Hercules cluster (M13), but it is certainly worth tracking down.
Messier 45, the Pleiades
Naked-eye open cluster in Taurus
Most people can see at least 5 stars with the naked eye in this cluster, but more can be seen if you have good eyesight and ideal viewing conditions. This is a great object for binoculars or a telescope with a wide-angle eyepiece.