Natural Calendar December 2014

Natural Calendar - December 2014

The purpose of this feature is to give scout leaders, educators and naturalists an idea of some of the natural events coming up each month. We will try to cover a variety of natural events ranging from sky events to calling periods of amphibians, bird and mammal watching tips, prominent wildflowers and anything else that comes to mind. We will also note prominent constellations appearing over the eastern horizon at mid-evening each month for our area for those who would like to learn the constellations. If you have suggestions for other types of natural information you would like to see added to this calendar, let us know!

Note: You can click on the hyperlinks to learn more about some of the featured items. To return to the Calendar, hit the "back" button on your browser, NOT the "back" button on the web page. All charts are available in a "printer friendly" mode, with black stars on a white background. Left clicking on each chart will take you to a printable black and white image. Please note that images on these pages are meant to be displayed at 100%. If your browser zooms into a higher magnification than that, the images may lose quality.

Though we link book references to nationwide sources, we encourage you to support your local book store whenever possible.

Notes and Images From November 2014

NGC 1300, November 18th, 19th and 20th. 12.5 Inch Newtonian Reflector and SBIG ST-2000XCM CCD Camera. Total exposure time 5 hours. Click the above image to see a high resolution version of the image and tour the galaxy with the Hubble Space Telescope.

The constellation of Eridanus represents a celestial river that begins near the brilliant blue supergiant Rigel, at the foot of Orion the Hunter. From there the river flows westward towards Cetus before making a sharp bend and then turning south. The modern day constellation ends in the bright star Achernar, which never rises above our southern horizon in Tennessee.

Other than Achernar, there are no really bright stars in Eridanus, so it tends to be overlooked among the brighter stars of Orion and Canis Major. But along the river are some striking deep sky objects. We imaged one of them in November, the classic barred spiral galaxy NGC 1300.

At a distance of nearly 70 light-years, this galaxy is a more distant target than many of the galaxies in the Messier catalog. The galaxy never gets more than about 35 degrees above the horizon from middle Tennessee, so it has to be imaged through quite a bit more of the atmosphere than galaxies which appear to pass overhead. To see NGC 1300 overhead, you'd have to be at 19 degrees south latitude, the latitude of central Boliva.

This region of sky is only about 30 degrees from the south galactic pole, and many faint background galaxies can be seen in the higher resolution version of the image. You can see it by clicking the image above. While there, take the time to follow the link to the zoomable Hubble telescope view of this galaxy. It is truly spectacular, and by zooming in you can see many background galaxies visible around and through NGC 1300, both in the Hubble image and in our image.

Tufted Nursery Web Spider, Pisaurina dubia, November 14th, Nikon D5100 camera and Nikon 105 Micro Lens. Click the above image to see a high resolution version of the image.

We came across this Tufted Nursery Web Spider, Pisaurina dubia, near our garden on November 14th. This species is quite striking and has a distinctive tuft between its eyes. Holding the front two pairs of legs together, and sometimes the rear two pairs as well, is common in nursery web spiders. We had not encountered this species before, but I'm told they are not uncommon in this area (Thanks Joel and Steve!) For a closer look at this one, click the image at right.

Sky Events for December 2014:

The winter solstice occurs on December 21st at 5:03pm CST, marking the beginning of Winter in the Northern Hemisphere.

Evening Sky:

Mars is less than 5 seconds of an arc now in apparent diameter, but still remains visible in the early evening. It will be making its way from Sagittarius into Capricornus this month.

Venus slowly climbs into the western sky after sunset in December. Look for it about 30 minutes after sunset as the month progresses.

Jupiter rises around 10:00pm CST at the beginning of the month in Cancer. Wait for it to climb high in the sky in the morning hours to get the best telescopic view.

Morning Sky:

The Geminid Meteor Shower peaks in the morning hours of December 14th. Conditions should be favorable until the third quarter Moon rises around midnight, then less favorable after that. To see a time lapse video I made of part of the shower last year (make sure you click "HD") click here. For most of the video, the camera is tracking the stars, so they will remain in one place while the meteors arc across the sky. There's a nice sequence towards the end where high altitude clouds roll in.

Saturn rises about an hour before sunrise at the beginning of the month in Libra. Look for it low in the southeast.

All times noted in the Sky Events are for Franklin, Tennessee and are Central Standard Time. These times should be pretty close anywhere in the mid-state area.

The Orion Nebula, Messier 42, February 2008, 85mm Apochromatic Refractor and & ST2000XCM CCD Camera, Total Exposure Time 2 Hours.

Constellations: The views below show the sky looking east at 9:30pm CST on December 15th. The first view shows the sky with the constellations outlined and names depicted. Star and planet names are in green. Constellation names are in blue. The second view shows the same scene without labels.

Look for the bright stars Castor and Pollux in the constellation of Gemini, The Twins. Compare the colors of the bright stars Betelgeuse and Rigel in Orion. Betelgeuse is a red giant and Rigel is a very hot, blue-white supergiant. If you have a telescope, point it to the center of the three "sword" stars below Orion's belt. There you will find the Orion Nebula, M42, one of the most magnificent emission nebulas in the sky. The pink glow of hydrogen alpha light is visible only in very large telescopes and the nebula appears as a small greenish glow in small telescopes. Crouching beneath the feet of Orion, is Lepus, the Hare. Sirius, the brightest star in the sky, shines below Orion. Sirius is in Canis Major, the Great Dog, and for that reason is known as the Dog Star. In the late summer, Sirius rises at the same time as the sun. Because of this, the late summer days are known as the "dog days." The faint constellation Monoceros, the Unicorn, follows Orion over the eastern horizon. Low in the eastern sky below Gemini is Canis Minor, with its bright star Procyon. Procyon means, "before the dog," and refers to the fact that Procyon rises just before the Dog Star, Sirus. Look below Gemini and see if you can spot the faint glow of M44, the "Beehive Cluster." This cluster is located in Cancer, the Crab. Finally, look just above the horizon to see bright Jupiter rising.

December 15th, 9:30pm CST, Looking East

On Learning the Constellations: We advise learning a few constellations each month, and then following them through the seasons. Once you associate a particular constellation coming over the eastern horizon at a certain time of year, you may start thinking about it like an old friend, looking forward to its arrival each season. The stars in the evening scene above, for instance, will always be in the same place relative to the horizon at the same time and date each December. Of course, the planets do move slowly through the constellations, but with practice you will learn to identify them from their appearance. In particular, learn the brightest stars (like Sirius and Procyon in the above scene), for they will guide you to the fainter stars. Once you can locate the more prominent constellations, you can "branch out" to other constellations around them. It may take you a little while to get a sense of scale, to translate what you see on the computer screen or what you see on the page of a book to what you see in the sky. Look for patterns, like the three stars in a line in Orion's belt.

The earth's rotation causes the constellations to appear to move across the sky just as the sun and the moon appear to do. If you go outside earlier than the time shown on the charts, the constellations will be lower to the eastern horizon. If you observe later, they will have climbed higher.

As each season progresses, the earth's motion around the sun causes the constellations to appear a little farther towards the west each night for any given time of night. If you want to see where the constellations in the above figures will be on January 15th at 9:30pm CST, you can stay up till 11:30pm CST on the December 15th and get a preview. The westward motion of the constellations is equivalent to two hours per month. For instance, if you want to see what stars will be on your eastern horizon on March 15th at 9:30pm CST (3 months later), you would need to get up at 3:30am CST in the morning on December 15th (3 months times 2 hours/month = 6 hours).

Recommended:

Sky & Telescope's Pocket Star Atlas is beautiful, compact star atlas.

A good book to learn the constellations is Patterns in the Sky, by Hewitt-White. You may also want to check out at H. A. Rey's classic, The Stars, A New Way to See Them.

For skywatching tips, an inexpensive good guide is Secrets of Stargazing, by Becky Ramotowski.

A good general reference book on astronomy is the Peterson Field Guide, A Field Guide to the Stars and Planets, by Pasachoff. The book retails for around $14.00.

Starry Night has several software programs for learning the night sky. Visit the Starry Night web site at www.starrynight.com for details.

The Virtual Moon Atlas is a terrific way to learn the surface features of the Moon. And it's free software. You can download the Virtual Moon Atlas here.

Cartes du Ciel (described in the monthly notes above) is a great program for finding your way around the sky. It is also free, and can be downloaded here.

Apps: We really love the Sky Safari Pro application described here. For upcoming events, the Sky Week application is quite nice. Both apps are available for both I-phone and Android operating systems. The newest version, Sky Safari 4, is available here.

Amphibians:

Upland Chorus Frog

December really marks the beginning of the breeding season for our Tennessee frogs and toads. We have had breeding choruses of Upland Chorus Frogs as early as December 4^th. Breeding even before Wood Frogs, these irrepressible inhabitants of flooded winter fields and other wet areas will call throughout the cold winter months. Listen for their call, which sounds like someone dragging their thumb across the teeth of a plastic comb, on mild wet winter evenings. Listen also for Southern Leopard Frogs. We hear them throughout the fall. Many other Tennessee frogs and toads can also be seen on mild December nights, but most are silent.

Recommended: The Frogs and Toads of North America, Lang Elliott, Houghton Mifflin Co.