Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into four sections; what you can see with the naked eye, with binoculars, with a small refracting telescope and with a Dobsonian reflector. 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 January 27th. For January, your best viewing nights will be from January 16th to the 31st. The Star chart below is set for Florence, SC on January 15th at 9 pm. Note: A table of contents for earlier columns is located in the February 2016 column.
Clear Sky Please:
Two years ago I noted, in this column, that although the causes of global warming are still being debated, the winters here have indeed been abnormally warm for the last few years. In general, warmer weather results in more moisture in the atmosphere, and also can cause atmospheric turbulence as the hot air rises and the cool air falls; both situations have a negative impact on nighttime viewing. If you are aiming your telescopes at simple targets such as the Moon and planets, you will not experience too much difficulty. However, there is so much beauty to be seen observing the dim DSOs (deep sky objects) such as nebulae, galaxies and star clusters. These DSOs require a clear dry sky to enjoy their grandeur. Another weather problem recently was when the warm days evaporated significant moisture from the ground, followed by cold nights resulting in heavy fog. The 2016 December Geminids meteor shower was washed out by a full Moon, but the 2015 Geminids were washed out by a heavy fog.
We can only hope that this month brings us a few clear dry nights to enjoy our new, or old, telescopes.
Catch Four Star Clusters and a Cat:
There are many star clusters for you to view, but let’s try to find four clusters in one small area of this month’s southeast sky. The four clusters are also Messier Objects; M35, M36, M37 and M38. The image below shows the southeast sky in mid-month, and the shaded area is the region to search for the four star clusters.
These four objects are open star clusters. They are not tightly grouped like globular clusters, but instead contain hundreds to thousands of stars in an area spanning 10 to 25 light years. The image below pinpoints their locations.
First look for M35 just off the left foot of the constellation Gemini. This is an easy target. If you can’t see M35 through your binoculars, then it is a bad viewing night or location; try another clear night. Once you have located M35, search for the other three open clusters using the chart above. Note: The image below shows M35.
Now move your binoculars toward the constellation Auriga to find the other three clusters. All three clusters are visible in the same field of view of a 7 or 10 power binocular. M38 and M37 will be somewhat easy to see, but M36 can be more difficult.
Where is the cat? An asterism is a group of stars that form a shape that is recognizable as a common object. Examples: The Big Dipper, the Little Dipper, the Northern Cross, the Cassiopeia “W”, and the Coathanger (in Vulpecula). There are many lesser-known asterisms reported in the night sky, and most take quite an imagination to visualize, but many are obvious. One of the more obvious but little known asterisms is in the constellation Auriga, mentioned briefly in this column three years ago. If you found M38 earlier, then you have seen the asterism known as the Cheshire Cat, or the Smiley Face. The image below shows the Cat and the position of M38. This asterism is easily seen with simple binoculars.
Always Check Out Andromeda:
All amateur astronomers are aware of the Andromeda Galaxy. On a clear night you can actually see it with the naked eye. Therefore, it is readily visible through simple binoculars. However, it always seems to look like the same fuzzy ellipse, as shown below.
Novices think it is just too far away (2.5 billion light years) to see it any better; that is a false assumption. Andromeda is so large that it would fill the view of some binoculars, it is too dim to see fully, not too far. What you see through you binoculars or telescopes is just the bright core of the galaxy. Note in the image below, the elliptical outline in the center of the image is the area you normally see through your binoculars.
The remainder of the Andromeda Galaxy that you don’t see is huge. So how can you view the entire galaxy? On any clear night when Andromeda is high up, and you are in a dark viewing area, “Always check out Andromeda.” Special note: When you are checking out the Andromeda Galaxy take your time, and stare intently, and one night the entire galaxy will “magically” appear.
If the Andromeda Galaxy were very bright, it would appear in the night time sky as shown below!
Naked Eye Sights: The constellation Orion; always enjoyable. Venus will continue to move higher in the western sky. The Pleiades, or Seven Sisters. You can only see six stars with the naked eye. In a very dark sky area, you might see eight stars, but never just seven.
Binocular Sights (7 to 10 power): The entire Andromeda Galaxy; very difficult, don’t get discouraged if you fail.
Big Binocular Sights (18 to 25 power): Best chance to see the entire Andromeda Galaxy. The Double Cluster in Perseus. The Pleiades. The Orion Nebula.
Telescope Sights (60-100mm): Orion Nebula
Dobsonian telescope (6 -8 inch): Try for the planet Uranus, may be hard to locate in Pisces, but once found, it is easy to see its blue color.
See you next month!