StarWatch: Moravian College Astronomy

AUGUST 2004

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414 AUGUST 1, 2004: August Perseids to Please: It has been over a decade since the US has been in a favorable position to partake in a good August Perseid meteor display. This year not only is the moon cooperating—it is just a few days shy of its dark phase, but North America, especially the Mountain and Pacific times zones, are literally on the bull’s eye as optimum locations to observe these shooting stars. Every year as the Earth circles the sun, our planet grazes the orbit of Comet Swift-Tuttle, colliding with the ribbons of particles ejected from this dirty ice ball throughout its countless circuits around the sun. This cometary dross, when plowing through the Earth’s atmosphere at speeds of 40 miles per second, produces the blazing streaks of pyrotechnics that have become known as the August Perseids. We encounter the debris of Comet Swift-Tuttle at essentially the same location in space, but that does not mean that our part of the world is set to see the main event. This year, North America will be rotating into the correct position just as Earth’s orbital motion carries us into the densest area of particles. It is as if we’ll be riding on the front windshield of a car moving through a swarm of mosquitoes—splat, splat, and splat. Even more exciting is the fact that Jupiter’s gravity has recently nudged these comet fragments about one million miles closer to Earth. This means that we should pass more centrally through the comet’s debris field—splat, splat, and more SPLATS! Don’t expect a spectacle like the Leonids produced in 2001, but 100 meteors per hour during the several hours before dawn on the morning of August 12 is not out of the question. These rates assume clear, dark, country skies with lots of unobstructed viewing area. Specific observing tips will be discussed in next week’s StarWatch.

415 AUGUST 8, 2004: Perseid Observing Tips: On the morning of August 12, the continuous United States is going to be well positioned for what is predicted to be a much better than average Perseid meteor display. The optimum viewing times will be during the several hours just before dawn when rates of 100 meteors per hours could be realized under clear, rural skies. The Perseids result when the Earth plows through dust particles ejected from Comet Swift-Tuttle as it orbits the sun. Each year, the Earth grazes Swift-Tuttle’s path near mid-August, colliding with this grit that creates the fiery Perseids that appear to radiate from the top of the constellation of Perseus the Hero. In fact, this radiating phenomenon will allow you to distinguish which meteors are indeed Perseids. Observers should dress for cooler fall-like conditions wearing a jacket, hat, thick socks, and even thermal underwear. An air mattress or lounge chair along with a sleeping bag and pillow will add extra comfort and warmth. Also think about dew. You’ll want a plastic painter’s tarp to throw over your bag and gear to help keep them dry throughout the night. A watch, clipboard, paper and pen, a flashlight, and another capped with red cellophane will allow you to navigate by white light and take notes by red. Bring along a warm, caffeinated beverage, but leave the Walkman behind. It will only distract and lower your meteor rates. Record your Perseid counts in 10-minute intervals. Face NE and view towards the zenith, the darkest part of the sky. Meteor rates will vary from under a dozen events per hour before midnight on August 11, but increase dramatically after 2 a.m. By dawn, streaking Perseids will be seen at the rate of 40 to 100 per hour. Although the morning of August 12 is best, Perseids will be visible all week.

416 AUGUST 15, 2004: Star Hill Inn: Sitting in front of a computer at Star Hill Inn near Sapello, New Mexico, with a US weather map in front of me, I can see two large regions where flood watches have been posted. One is centered on eastern PA where I live. The other is the SE quarter of New Mexico, including San Miguel County. You can guess where I’m located? All right, that’s the bad news. The good news is that despite the gloomy skies, I am still having a ball at America’s oldest retreat for urban astronomers. The summer monsoon season, when moist Pacific air is uplifted over the Sangre de Cristo Mountains, can produce quirky weather patterns, to be sure. Often you can hear distant thunder by 11 a.m. as developing storms begin to push slowly over the peaks. Sometimes it can thunder all day without a drop of rain, but somewhere rain is cleansing the air. When a big storm does push through, the mountains reverberate like huge kettledrums echoing the rumbling thunder back and forth, layering the volleys, to create a continuous din of sound. No need for a phone or a satellite dish here. There is plenty of daytime entertainment. But what about the nighttime sky at Star Hill Inn? It often clears between 1-3 a.m., and make no mistake, there are totally cloudless summer nights. The dust-free air, the 7200-foot elevation, and a pungent soughing conifer forest that reflects almost no light back into space make an unbeatable combination for clarity. Fifty minutes after sunset under a vibrant lapis sky, I can see more stars at Star Hill Inn than from my backyard in suburban Coopersburg on the darkest of nights. You can find out more about SHI at www.starhillinn.com. I’ll be writing about some of my celestial experiences here over the next several weeks.

417 AUGUST 22, 2004: Go for the Gusto: I have been shooting digital images of the night sky for over five years, the last two using an Olympus E20N single lens reflex camera. Even through I am now using older technology, I am still astonished by the E20N’s astronomical capabilities. In order to image for longer periods of time, the E20N records a dark frame, a picture with the shutter closed to map the unwanted electronic noise of the chip. This noise is then automatically subtracted from the image in the camera’s buffer while being transferred to storage. Until this spring I had only photographed the night sky with the camera steadied by a tripod, but when Comet NEAT showed up in May, I finally piggybacked the E20N to my telescope so that star images would not be smeared by the Earth’s rotation. The results were pretty much what I expected. My light polluted environs nearly washed out the comet in a one-minute exposure. Using Paint Shop Pro, I was able to massage away the yellowish background glow from the high-pressure sodium vapor streetlamps and create a relatively pleasing picture of NEAT. When I traveled in July to the dark skies of Star Hill Inn, an astronomy retreat near Sapello, New Mexico, I decided to go for the gusto and shoot only digital images. WOW! I was simply blown away by the striking photos of the Milky Way and other star fields that I had captured with the E20N. The colors of the stars were true, and the sky in between had a mostly neutral hue. Several Star Hill Inn photos are posted with this week’s web StarWatch. Even if your digital camera is simply a “point and shoot,” get a small beanbag or tripod for support and try to capture the western horizon colors 20 to 40 minutes after sunset. You’ll truly be amazed by the results. Go for the gusto!

418a AUGUST 29, 2004: Muhlenberg's Robotic Telescope Observatory: It all began because of an act of kindness from a stranger. Friends, John Sefick (NM), Tracy Brockwell (VA), and I were observing with portable equipment at windswept Siding Spring Observatory in New South Wales, Australia in early February 2001. Australia’s National Observatory is located 215 miles to the NW of Sydney in Warrumbungle Nat. Park. It was okay for guys to rough it outside all night, but telescope operator and astronomy enthusiast, John Shobbrook thought otherwise for Tracy. Coincidentally, a roll-off-roof observatory was available with plenty of space to set up our gear, and most importantly, bathroom facilities. Throughout our 21-day stay, John Shobbrook was on hand to smooth out the rough edges, to advise, to give us observatory tours, and also to invite us to his home for casual get-togethers and meals. John and Jan Shobbrook’s Aussie hospitality made a lasting impression on me. Shobbrook was also obsessed with constructing a robotic telescope that could be remotely controlled through the Internet, and we exchanged e-mails about the concept after I returned to the Valley. Then in July of 2001, Muhlenberg College received a NASA grant in part to build a robotic observatory in Germansville, PA. The project would allow for participation by local schools. Yikes… Germansville, I lamented. I connected Dr. Bob Milligan, Physics Dept. Chair, with John Shobbrook, and the telescope site gradually moved Down Under. John came to Allentown last week to celebrate the completion and on-line status of the new Muhlenberg Robotic Telescope, located just below Siding Spring. Life has its twists, but kindness can have its rewards too. Venus meets Saturn tomorrow.

418b AUGUST 30, 2004:   Venus Passes Saturn This Week
In mid-July when I was observing at Star Hill Inn in Sapello, NM, I was hoping to glimpse Saturn during morning twilight. Alas, it was not to be because the Ringed World was only eight degrees from the sun. However, Venus was amazingly vivid, not only lighting up the area of the sky in which it was located, but casting shadows across the observing deck, reflecting the dewdrops that wetted objects in the cool, water-saturated air. Venus was a memorable sight in the bluing sky of morning. Forty-five days later, Saturn and Venus are easy targets in the brightening dawn sky. In fact, this week will be the best time to see both planets because of their nearness to each other. Look due east at 5 a.m., and white Venus will be an absolute knockout. To Venus’s left will be yellowish Saturn, unmistakable because of its brightness and close proximity to the Goddess of Love. The only other celestial competitors will be Sirius, the brightest luminary in the nighttime heavens, about 40 degrees to the right and just rising in the southeast, and the moon in the west. As the week progresses, Venus will inch past Saturn, reaching its closest separation on Tuesday morning when it will be just shy of two degrees or four moon diameters from the Ringed World. The difference in separation on Wednesday morning will be just 1/60th degree less, but Venus’s movement will be very obvious. By Saturday, Venus has pulled away from Saturn to a distance of nearly four degrees. Regardless of which mornings are clear, Venus and Saturn will be stunning. Don’t forget the binoculars or spotting scopes. At 20x, the crescent of Venus and the rings of Saturn will be easily visible in the same field. A photo and a map are posted at web StarWatch at the URL below.

Venus passes Saturn:   Venus is the brightest object in this 5:15 a.m. digital photo taken on September 1 from Coopersburg, PA. Saturn is immediately above and to the left of Venus. The other stars in the photograph are part of winter constellations that will be dominating the sky in February 2005. See the map which can be found below this picture. Gary A. Becker photo…

Venus Reigns:   The bluing towards the bottom left of this six-minute digital image announces the dawning of a new day at Star Hill Inn near Sapello, New Mexico. Venus reigns in the lower right of the picture. Above it is yellowish Aldebaran in Taurus the Bull, and the Pleiades star cluster. The bright star on the left is Capella of Auriga the Charioteer. Gary A. Becker digital photo, July 21, 2004...