Natural Calendar June 2009

Natural Calendar - June 2009

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.

Notes and Images From May 2009

NGC 5907, May 18th and 19th, 6 inch Refractor at f12 and ST2000XCM CCD Camera, Total Exposure Time 480 minutes.

The long tail of Draco the Dragon winds around Ursa Minor, the Little Bear, and separates it from its mom, Ursa Major. The three constellations are well placed for viewing in the late spring sky. Just above one coil of the dragon's tail is the edge-on galaxy NGC 5907.

We imaged the galaxy on May 18th and May 19th, following a cold front that swept away the clouds that had persisted most of the month. The sky was wonderfully clear and dark, and the star images were very small and steady. A chorus of Northern Cricket Frogs drifted up from our pond as the hours of exposure ticked by.

NGC 5907 was discovered in 1788 by William Herschel. Most estimates place it at a distance of around 40 million light-years. Using averted vision, I've seen it as a faint narrow streak of light in my 85mm Televue refractor. A 6 inch telescope will give you a better view. As with all deep sky objects, you need a clear dark sky. It's always interesting to see what each new image brings. Looking at this image, It appears that one spiral arm on each side of the galaxy is somewhat sprung out from the inner arms. The outermost arm on the right side of the galaxy appears to be coming at us from behind the galaxy. The outermost arm on the left side of the galaxy appears to be curving around away from us. As in most galaxies, the older populations of stars dominate the center portions and glow yellow-orange. Newly formed stars in the spiral arms are predominantly bluish.

Eastern Milksnake, May 11th, Nikon D40X

We came across this Eastern Milksnake, Lampropeltis triangulum, on May 11th. These beautiful snakes are harmless and beneficial, feeding on a variety of small rodents, lizards and other snakes. Prey is killed by constriction. Their smooth scales help distinguish them from Rat Snakes or Corn Snakes, which have weakly keeled scales. The interesting common name comes from an old legend claiming that milksnakes somehow approach cows, put them in a trance-like state, and suck the milk from their udders. Some farmers whose milk production was below normal attributed their misfortune to the presence of a milksnake in the field.

Sky Events for June 2009:

The Sun is at the Summer Solstice at 12:46am CDT on June 21st, marking the beginning of summer in the Northern Hemisphere.

Evening Sky:

A nearly full Moon will occult the bright star Antares on the evening of June 6th. For our area, Antares should disappear behind the moon around 9:10pm EDT and should reappear around 10:20pm EDT. The occultation begins at dusk, and it should be stunning to watch the bright orange star disappear. Binoculars will help you see the occultation much better.

Saturn is in the southwestern sky at dusk as the month begins, In Leo. The rings are almost edge-on, tilted only about four degrees. Because of the diminished brightness of the ring system, you may be able to see fainter satellites of Saturn than you normally do with a given telescope.

Jupiter rises a little before midnight at midmonth and by dawn is almost due south.

Morning Sky:

Venus rises around 3:00am at midmonth and is about 20 degrees above the eastern horizon at dawn. On the morning of June 19th, look for fainter Mars about 2 degrees up and to the right of Venus. On the same morning, you may be able to spot Mercury very low in the east. Binoculars should help find it.

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 10:00pm CDT on June 15th. The first view shows the sky with the constellation 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. New constellations this month in the eastern sky are Lyra, the Lyre, with it's bright star Vega, Cygnus, the Swan, and Aquila, the Eagle. The bright stars Vega, Deneb and Altair form the "summer triangle."

June 15th, 10:00pm, 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 June. 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 Altair and Vega in the above scene looking east), 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 the constellation Lyra.

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 July 15th at 10:00pm CDT, you can stay up till 12:00am CDT on June 15th and get a preview. The westward motion of the constellations is equivalent to two hours per month.

Sky Publishing has just come out with a beautiful and compact star atlas, Sky & Telescope's Pocket Star Atlas. It is destined to become a classic, and is a joy to use at the telescope.

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.

Amphibians:

Cope's Gray Treefrog

In June the treefrogs really hit their stride. Listen for Cope's Gray Treefrogs, Gray Treefrogs, Bird-Voiced Treefrogs, Green Treefrogs and Barking Treefrogs. Northern Cricket Frogs and Southern Cricket Frogs call a lot during June, and the calls of Bullfrogs and Green Frogs fill the night air. After heavy rains listen for the high, insect-like call of the Eastern Narrowmouth Toad and the strange-sounding Eastern Spadefoot.

Birds:

Now is a good time to get to know the breeding birds of Tennessee. It's fun to take a trip to the Great Smoky Mountains National Park in June and hike a high altitude trail, like the Alum Cave Bluff trail. By doing so you can encounter birds that breed in Tennessee at these higher elevations, like Black-throated Blue Warblers, Canada Warblers, Chestnut-sided Warblers and Blackburnian Warblers.

Recommended:

Bird Finding in Tennessee, Michael Lee Bierly. A classic guide to finding birds in Tennessee.

The Sibley Guide to Birds, David Allen Sibley

The Sibley Guide to Birds of Eastern North America, David Allen Sibley

An inexpensive guide for beginners is the Golden Guide for Birds.