Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on October 12. For October, your best viewing nights will be from October 5 to the 17. The Star chart below is set for Florence, SC on October 15 at 9 pm.
September Lunar Eclipse:
Sadly most of South Carolina was completely cloud covered during the eclipse. This was a “perfect” lunar eclipse for a potential 3D view of the Moon. The next total lunar eclipse in our area will not occur until January 21, 2019. This eclipse will also occur late in the evening with totality between 11:30 pm to 12:30 am. This timing sets up the same possibility that we will see the spherical nature of the Moon (See last month’s column).
Viewing the Autumn Skies:
In the eastern United States the majority of star parties occur in the autumn. The reasons are the cooler nights and lower humidity result in clearer skies. Another plus is that there are many great targets to observe in the fall. These targets include: globular clusters, open clusters, planetary nebulae, galaxies, and other targets.
Globular Clusters: The two best globular clusters in the northern hemisphere are the Hercules Cluster (M13) and M22 in Sagittarius. Although they are low in the sky this month, the clearer skies make them good targets. During this month they can best be seen between 8 pm and 9 pm. Below is the location of M13.
Below is the location of M22.
There are various open clusters visible this month; however the nicest target all month is the Double Cluster in Perseus. The only designations of this object are NGC884 and NGC 869. Note: NGC stands for New General Catalog, a listing of deep sky objects published in 1888. The Double Cluster is best viewed with binoculars or low power telescopes. If you observe from a good observing site it is a nice target. If you view the Double Cluster from a truly dark sky site it looks like two piles of jewels on black velvet. These clusters are just below the Cassiopeia “W.” The locations are shown below:
There are two nice planetary nebulae to check out. Planetary nebulae were mislabeled by early astronomers. In reality, they are remnants of star deaths. Our Sun should end its life as a planetary nebula. These objects can form many shapes, and the two I will point out are named after their shapes. The first is the Dumbbell Nebula (M27) in the constellation of Vulpecula; however you can easily locate this target by using the constellation Cygnus. You can see M27 with binoculars or a small telescope.
The location of M27 is shown below:
The second target is the Ring Nebula (M57) in Lyra. This object is a perfect ring, however, unlike M27; M57 will require a telescope at high power such as a six inch Dob using from 25 to 10 mm eyepieces. The location of M57 is shown below:
There are various galaxies visible this month. The best target is the famous Andromeda Galaxy (M31). This galaxy can be seen with the naked eye from dark sky sites. Through most amateur telescopes, M31 looks impressive, but what you are seeing is only the central core of this massive object. Once you go above 25 power, you cannot see the entire galaxy. The absolute best equipment for observing M31 are large binoculars; such as 25 X 100mm. Binoculars this size start at about $300.00; of course you have to also purchase a tripod. If you one day view the Andromeda Galaxy through a pair of large binoculars you may be upset that you still only see the central core of the galaxy. Large binoculars are indeed the best tool for seeing dim galaxies, but you still need near perfect dark sky conditions, so keep trying. Below left shows 25 power on normal night and on the right is the same view at a dark sky site.
Other Autumn Sights:
Check out the star Albireo in Cygnus; which without hesitation I call my favorite star. Albireo is the star that marks the head of the swan or the star that marks the bottom of the Northern Cross asterism. This colorful double star has one sapphire colored star and one golden colored star. It is best viewed at 25 power or above either with a telescope or with large binoculars. The general consensus is that it is a true double star and not a chance alignment.
Collinder 399 is also known as the Coathanger and Brocchi’s Cluster is an asterism in the vicinity of the star Albireo. This asterism consists of ten stars in the shape of a coathanger. This asterism rises in May and sets in the west in November, but throughout this time it is always seen upside down. In the southern hemisphere it is always seen right side up. Another plus is that the Coathanger is best viewed through seven or ten power binoculars. In this case the stars in the asterism are not associated with each other but are just a chance alignment ranging from 200 to 1,100 light years away. Therefore the name Brocchi’s Cluster is a misnomer. See below:
Naked Eye Sights: The Summer Milky Way is still partially visible. Try to see the Andromeda Galaxy with the naked eye.
Binocular Sights (7 to 10 power): Try for M13, M22, M27, M31, NGC 884 and 869. Also check out the Coathanger asterism.
Telescope Sights (60-100mm): Try for M13, M22, and M27. Also NGC 884 and 869 at low power. Don’t forget the star Albireo.