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 December 29th. For December, your best viewing nights will be from December 1st to the 4th and the 19th to the 31st. The Star chart below is set for Florence, SC on December 15th at 9 pm. Note: A table of contents for earlier columns is located in the February 2016 column.
Geminids Meteor Shower:
For several years, the best meteor shower of the year has been the Geminids, peaking on December 13th and 14th. This trend may likely continue, but the most important variable for this, or any meteor shower, is the Moon phase. This December, the full Moon is on December 13th, therefore, this should result in a total washout for 90% or more of the meteors. The future good news is that December 2017 and 2018 will be good Geminids viewing years.
One goal of most amateur astronomers is to see all of the planets in our solar system. The easily viewed planets are Venus, Mars, Jupiter and Saturn. Mercury is also easy to see, but only when is perfectly positioned in its orbit. That leaves Uranus and Neptune. Uranus is much closer than Neptune, and it can be seen with the naked eye at a dark sky location. Also, Uranus will show its beautiful blue color through most amateur telescopes. Therefore, the most difficult planet to find is Neptune. Neptune will not be visible through the naked eye, but it can be seen with simple binoculars. Difficult to locate celestial objects are best found when they are near an easy to spot target. Near the end of this month, Neptune will have the closest alignment to Mars since the year 1305. So if you wish to check this planet off your viewing list, your best chance will be early in the evening on December 31st. Look to the southwest starting just before 7 pm. A thin crescent Moon will just be setting in the west, and above the Moon you will see the bright planet Venus. Above Venus and slightly to the left will be the planet Mars. Mars should be the brightest object in that area of the sky. Once you located Mars, the planet Neptune will be above and to the left of Mars, see diagram below. In the diagram, top left shows the general area, top right image shows planet separation through simple ten power binoculars and bottom image shows planet separation through a simple telescope.
Through an amateur telescope you should also be able to see the bluish color of Neptune, but due to its extreme distance, is usually a dull blue versus the brighter color of Uranus. Good luck with your search.
Note: If you are up to the challenge, Uranus is also visible this month well above and to the left of Neptune in the constellation Pisces. The major difficulty finding Uranus in this area of the sky is the absence of easy markers to locate this planet. You will need a good star chart and some patience if you hope to find this blue planet.
What you can and can’t see in Orion:
Orion still remains the most visible and well known of the constellations. It will spend most of this month in the southeast sky. Known for its famous belt and sword asterisms, there are two well-known objects in Orion that I have yet to see.
First let’s start with what you can easily see. The Orion Nebula (M42) appears to be the center star of Orion’s sword. With any simple pair of binoculars, you will see it as a gaseous nebula. I have found over the years that large binoculars are the best viewing tools for observing nebulas. Nebulae can be seen through telescopes, but using two eyes allows the brain to better process the image. Through large binoculars, the gaseous Orion Nebula will look like a diving eagle with its wings out spread.
Some things you can’t see in Orion challenge amateur astronomers worldwide. The first elusive target is the Running Man Nebula. This target is easy to locate, it appears as the top star in Orion’s sword. However, the gaseous nature of the nebula is much less visible than the Orion Nebula. We are trying to view this nebula with ScienceSouth’s 150 mm X 25 power binoculars. The main requirement is a dark very clear night. Hopefully we will be successful this winter. The image below shows the large Orion Nebula on the bottom, and the Running Man on top. If you look closely, you can see the man’s head, his arms stretched out, and part of his legs.
A second potentially more elusive Orion target is the Horsehead nebula. This dark nebula is to the left of Orion’s belt. This nebula is an easy target for large observatory telescopes, see below, but it is a most difficult target for amateurs, myself included.
It usually requires filters to view it, but it has been reported that it can be seen with our 150 mm X 25 power binoculars. So as you look up at Orion this winter you may hope as I do to someday see these two “unseen” targets in Orion. Below is a broad field long exposure photo of the Orion constellation.
Naked Eye Sights: The Orion constellation and the Pleiades cluster
Binocular Sights (7 to 10 power): The Orion Nebula
Telescope Sights (60-100mm): Your best chance to see the planet Neptune and maybe Uranus.
Dobsonian telescope (6 -8 inch): Your best chance to see the planet Neptune in color