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!
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Though we link book references to nationwide sources, we encourage you to support your local book store whenever possible.
Notes and Images From October 2010
October brought dry and windy conditions. At night the atmospheric turbulence made the stars twinkle not only near the horizon but directly overhead. The combination of wind and turbulence made it hard to image with the long focal length of the 6" refractor. We chose instead to do some imaging with a 300mm Nikon lens attached to the CCD camera. This gives a wide field of view and is a lot more stable in windy conditions.
We imaged Messier 31, the Andromeda Galaxy, on October 1st and 2nd. The companion galaxies M32 and NGC 205 are visible above and below M31. A faint tidal bridge connects NGC 205 to Messier 31. The Andromeda Galaxy is about 2.5 million light-years away, and can be seen with the naked eye or binoculars on clear nights. It has been known since antiquity, and is referred to as the "little cloud" on star charts made in the 10th century.
Our Milky Way Galaxy and the Andromeda Galaxy are approaching each other and are expected to collide in approximately 4.5 billion years. The two galaxies may merge into a single giant elliptical galaxy at that time.
In the Natural Calendar for October, 2010, we wrote about a really nice binocular view of the North America Nebula. On October 7th we used a filter to image this nebula and its neighbor, the Pelican Nebula, in hydrogen alpha light. The Nikon 300mm lens was again coupled to the CCD camera.
These two ghostly emission nebula are near the bright star Deneb in Cygnus. Both are part of a vast cloud of ionized hydrogen gas approximately 1800 light-years distant. Each hydrogen atom is composed of one proton and one electron. Intense stellar radiation strips the electron from hydrogen atoms in the nebula. When a free electron recombines with a free proton to form a hydrogen atom, it emits a photon of light at the characteristic wavelength of hydrogen alpha light, 656 nanometers, in the red part of the spectrum. The hydrogen alpha filter effectively blocks virtually all wavelengths except for the hydrogen alpha wavelength. The entire nebula complex is around 100 light-years in diameter. Clicking on the image above will take you to a full size negative image of the nebula. To see the nebula complex as the color CCD camera registers it in the color of Hydrogen alpha light, click here.
Though the outline of the North America Nebula can sometimes be traced out with binoculars on clear moonless nights, the Pelican is quite faint.
Sky Events for November 2010:
Look for Jupiter about 30 degrees above the east southeast horizon at dusk at the first of the month. It will appear before any other star-like object. This is a great time to view the giant planet.
Both Mars and Mercury are very low in the southwestern sky after sunset, but are lost in the twilight glow without optical aid.
The Leonid Meteor Shower peaks in the early morning hours of November 17th and November 18th.
Saturn rises in the predawn sky early in the month, and gradually climbs higher as the month progresses.
Venus appears very low in the east southeastern sky about 25 minutes before sunrise on November 2nd. As the month goes by, it will climb higher in the sky each day. It's worth seeking out with binoculars or a small telescope early in the month. The planet will be a beautiful very thin crescent, a full 1 minute of an arc in diameter and visible as a tiny crescent even in binoculars. This is our favorite time to view Venus. Stop your search or viewing after sunrise, as you could do permanent and severe damage to your eyes if you sweep across the Sun.
All times noted in the Sky Events are for Franklin, Tennessee and are Central Daylight Time. These times should be pretty close anywhere in the mid-state area.
Constellations: The views below show the sky looking east at 9:30pm CST on November 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. The Pleiades, a beautiful open star cluster, is now well up in the sky. The entire cluster is wreathed in faint nebulosity. The nebulosity surrounding the bright stars of the Pleiades shines by reflected light. Dust illuminated by the stars in the cluster reflects predominantly blue light. Normally, the only part of the nebulosity visible in small telescopes is the purple-tinted area below Merope, and even then a very dark sky is required to see it. The Merope Nebula was discovered on October 19th, 1849 by Tempel, using a 4" refractor. He described it as appearing like "a breath on a mirror." In the above image, Merope is about three quarters of an inch above bottom center. Auriga, the Charioteer, with its bright star Capella, and Taurus, the Bull, with its bright star Aldebaran, are both prominent in the eastern sky. Look for the bright stars Castor and Pollux as the constellation Gemini, The Twins, clears the horizon. In the southeast, mighty Orion clears the horizon with its bright stars Betelgeuse and Rigel. Note the difference in color between the two stars. Betelgeuse is a red giant and looks orange. Rigel is very hot supergiant and looks bluish. Looking at the center of the three "sword" stars with binoculars, you can see M42, the Orion Nebula. Just poking its head above the horizon is Lepus, The Hare.
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 November. 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 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 stars that make up Orion.
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 December 15th at 9:30pm CST, you can stay up till 11:30pm CST on November 15th and get a preview. The westward motion of the constellations is equivalent to two hours per month.
Sky & Telescope's Pocket Star Atlas is beautiful, compact star atlas. It is destined to become a classic, and is a joy to use at the telescope.
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.
We think of November as the quietest time of year for Tennessee frogs and toads. However, some song can still occasionally be heard. Listen for Spring Peepers, Upland Chorus Frogs and Southern Leopard Frogs. Checking around ponds at night with a flashlight held next to your temple will many times show the eye shine of Southern Leopard Frogs, Green Frogs and Bullfrogs. As in October, you can locate many of the frogs and toads that have been calling more frequently earlier in the year by driving the back roads slowly on rainy nights. This is a two person job. One person watches the road for amphibians and one person looks out for other vehicles.
Recommended: The Frogs and Toads of North America, Lang Elliott, Houghton Mifflin Co.
You probably have already put out your bird feeders, but if you haven't you'll be missing out on a lot of good looks at winter feeder birds. This is a great time of year to start learning bird identification. Watch and listen for fall arrivals like White-throated and White-crowned Sparrows, Yellow-bellied Sapsuckers, Red-breasted Nuthatches and Brown Creepers. Listen for Great Horned Owls dueting at dusk and dawn and sometimes through the night during their courtship period.
The Sibley Guide to Birds, David Allen Sibley
The Sibley Guide to Birds of Eastern North America, David Allen Sibley
A Field Guide to the Birds of Eastern and Central North America, 5th edition. 2002. Roger Tory Peterson and Virginia Marie Peterson.
An inexpensive guide for beginners is the Peterson First Guide to Birds of North America.
We find that fall is a good time to listen at dusk for Southern Flying Squirrels. If you have a nut-bearing tree or trees near you, they may be used by these interesting nocturnal mammals. Listen for very high-pitched, metallic squeaks coming from the canopy. To my ear they sound a little like the sound that steel rails make (the "singing") when a train is approaching. If you are very fortunate, you may be able to spot one. If you do, note the large eyes and the flattened tail, which they use like a rudder to steer their flight path. They fly, or rather glide, by extending a fold of skin that is attached to all four wrists. When they extend their legs outward, this flying membrane forms a flat surface beneath their body, allowing flight.
Flying squirrels are very adept gliders. Although most glides are between 20 and 30 feet, one glide was measured covering 270 feet. Turns in the air of over 90 degrees are sometimes made. They are year-round residents.
The Wild Mammals of Missouri, Charles W. Schwartz and Elizabeth R. Schwartz. University of Missouri Press. Although not written for Tennessee, most of the species covered in the book do occur in this state, and it is our favorite book on mammals. The book is beautifully illustrated with the drawings of Charles Schwartz and contains a wealth of information. If you buy only one book on mammals, we recommend this one.
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Nature Notes Archives: Nature Notes was a page we published in 2001 and 2002 containing our observations about everything from the northern lights display of November 2001 to frog and salamander egg masses.
Night scenes prepared with The Sky Professional from Software Bisque
All images and recordings © 2010 Leaps