December 1, 2017
Night Skies: December is a great time to take a look at Orion
By GERRY LEBING
constellation Orion will rise at 6:40 p.m. on December 1 and will
completely cover the Eastern horizon by 7:40 p.m. Most sky watchers can
easily pick out the stars that form the body, belt, and
sword of this mythological hunter, but may not realize how much
this area of the sky has to offer.
Let’s put a name on some of the major stars in Orion. The bright
red giant in the upper left is Betelgeuse. (Don’t say that name three
times fast or you might have Michael Keaton as a visiter!) It’s the
ninth brightest star in the night sky with a magnitude of +0.56.
Betelgeuse has a very faint companion star with a visual magnidtue of
+14.5. Betelgeuse is 500 light years away.
To the right of Betelgeuse is Bellatrix. It’s a blue-white star double
star with visual magnitudes of +1.65 and +13. Bellatix is 240
light years away from us.
In the lower right is Rigel. It’s the brightest star in the
constellation, with visual magnitude of +0.2. Rigel is the 7th
brightest star in the night skies, and is a blue-white supergiant
star. It’s about 860 light years away.
Three significant stars form the belt of Orion. Going from right to
left, they are Alnitak (740 light years away), Alnilam (2000 light
years away), and Mintaka (690 light years away.)
The area adjacent to Alnitak contains both the Horsehead Nebula and the
Flame Nebula. Both of these Nebula are about 820 light years
away, so they really don’t surround the star.
Now take the time to look at the middle star in the sword. Does
it look a little fuzzy? The “fuzz” is caused by a huge bright
nebula, M42, the Orion Nebula. Don’t just look at the image of
Orion that is borrowed from NASA - go Outside and take a look for
yourself. If you have reasonably decent eyesight, on a clear, dark
night you can see this nebula with your naked eye! Break out your
binoculars to get a closer look at it. I recently used a pair of
“birding” binoculars to view M42, and it is simply stunning! And
things only get better if you have access to a telescope…
This is a very quick shot I took of M42 in November. M42 has a
visual magnitude of +4 and it’s over 1300 light years away.
Other things you can look for in December 2017
Saturn and Mercury will begin the month low in the sky near the Western
horizon right after sunset. You should be able to get a view of
them for the first week of December.
Neptune, Uranus, and Pluto will be in the evening skies. Uranus
is the only one of the three you can see without a telescope or
binoculars. With a visual magnitude of 5.9, Uranus is pretty
tough to find, but I actually did see it with my naked eye in November!
I also got this image of it:
If you’re an early riser, you can see Venus, Jupiter and Mars in the
Eastern pre-dawn skies. Mercury will join them around December
20. Mars will start the month rising at about 3:15 a.m. and
Jupiter will follow at 4:35 a.m. Venus won’t be visible until
after 6:10 a.m., and will not be visible after December 12.
The Geminid Meteor shower peaks the night of December 13. You can
expect as many as 120 meteors per hour with the chance of a fireball or
two. The action appears to start near the twin Gemini twin stars
Castor and Pollux. Look for this pair to appear near the Eastern
horizon at about 8:00 p.m. With any luck, you will be able to watch
this meteor shower all night long.
The Ursa Minorids peak on the night of December 22. It is
expected to generate about 10 shooting stars per hour. It’s easy
to find - simply look for the North Star.
1st Quarter is the 26th
Full Moon is the 3rd
Last Quarter is the 10th
New Moon is the 18th
Lebing is a retired computer scientist with the U.S. Geological Survey
in Washington, D.C. He has visited Hatteras Island since the
mid-1970s. He and his wife, Karen, have owned property here for several
years and moved to their home in Waves full-time in 2013.
Astronomy is a subject that Gerry says he has always been interested in
and one that he pursues seriously -- he's built an small observatory
next to his house. You can send him questions about the night sky
through e-mail, [email protected]g.)