StarWatch: Moravian College Astronomy

AUGUST 2010

AUGUST STAR MAP | STARWATCH INDEX | MOON PHASE CALENDAR

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Venus, Mars, and Saturn (right to left) join in saying hello on the evening of July 26. A 15 second guided image was taken at 9:47 p.m. EDT with a Canon 40D camera and 24-70mm zoom lens at an EFL of 56mm, F/4.0. A second image with the drive stopped was then snapped to capture the moonlit foreground. The two frames were combined into a single image using Paint Shop Pro. Gary A. Becker photography near Coopersburg, PA, Schantzenbach field...

Venus (right and brightest), Saturn (above) and Mars (below Saturn) played a game of hide and seek on July 30 as clouds moved into the scene from the NE. Even Spica got into the act (upper left). Here they cooperated for the last time in this 15 second exposure, F/4.0, ASA 400, 56mm EFL image. Don’t think those rosy clouds are part of a summer’s sunset. That’s Allentown, PA spilling its sodium light into my Coopersburg sky. Still the effect was not objectionable. Gary A. Becker photography, Schantzenbach field...

Venus (below and brightest), Saturn (above) and Mars (left and faintest) form a tight triangle on August 7 at 9:20 p.m. in the western sky. Haze near the horizon made it difficult to see Saturn and Mars with the unaided eye. A light pollution filter was used to dampen the sky glow from Allentown, PA in this 25 second, EFL 112mm, F/4.0, ASA 640, equatorially driven image taken with a Canon 40D camera. A photo of the horizon with the drive disengaged was superimposed over the driven picture to keep the horizon sharp. Gary A. Becker photography near Coopersburg, PA, Schantzenbach field...

Venus and Mars leave Saturn in their dust. Venus (below and brightest), Mars (above Venus), and Saturn (right) form a skinny triangle low to the horizon in the western sky on August 19 at 9:01 p.m. Both Saturn and Mars were not visible to the unaided eye. The sky was imaged with a Canon 40D camera at 25 seconds, EFL 112mm, F/4.0, ASA 400, on an equatorially driven mount. To capture the foreground in focus, a 45 second photo of the horizon with the drive disengaged was superimposed over the driven picture. A bright (81 percent lit) waxing gibbous moon was near the meridian in the south. The bright, bluish star to the far left is Spica, the alpha star of Virgo the Virgin. Gary A. Becker photography near Coopersburg, PA, Schantzenbach field...

One of the ugliest days imaginable turned into the clearest summer sunset of the season. Hoping that I’d get one last chance to photograph the Venus, Mars, Saturn grouping, I headed up to Schantzenbach’s field, west of Coopersburg, PA where I have been given permission to photograph. I was not disappointed. Venus is the brightest object in the frame, while Mars is above and to Venus’ right. Saturn hangs low, just above the tree line to the right of center. The picture was a composite of a 25 second equatorially driven image taken at F/4, ASA 400 and a 45 second picture with the drive off to capture the moonlit field. The EFL was 56mm. Gary A. Becker photography…

728 AUGUST 1, 2010: Ready, Set, Go Perseids!: As we enter August, the moon is waning and will be at last quarter early on Tuesday morning. This is good if you are an aficionado of viewing meteors because August is the month of one of the most reliable showers, the Perseids. The US is not in the sweet spot this year, but that may also have its advantages. While we will miss the highest meteor rates, we are presented with two mornings, August 12 and the 13, where observations should produce good activity. Meteor rates pick up after midnight and are usually highest at dawn. During this time the Earth rotates into the particles from Comet Swift-Tuttle’s tail, and we face into the debris in a similar fashion that the front windshield of a moving car gets splattered by more raindrops than the rear window. When a piece of fluffy cometary dust, smaller than a sand grain, slams into the Earth’s atmosphere about 70 miles up, a column of air about a half mile wide is made to fluoresce (glow), causing the meteor phenomenon. Brighter meteors may descend to an altitude of 50 miles or lower before they are completely abraded. Perseid meteors will not be hard to spot. These shooting stars are fast, often leaving a trail of glowing atmosphere behind them called a wake or a train. Perseids will look as if they are diverging from a location near the head of the constellation of Perseus the Hero. This is attributed to perspective. Straight sections of road or railroad tracks will appear to have a vanishing point in the distance, even though the sides of the roadway and tracks are parallel to each other. Likewise, the meteoroids in space are traveling parallel to one another in their individual orbits around the sun, and as they approach an observer, they will appear to diverge or radiate away from a vanishing point. All of these attributes will make it easy to identify Perseids against the background of other meteor activity. More next week...

729 AUGUST 8, 2010: Perseids Always Please: Late summer is typically known as the time to see meteors, and August’s Perseid Meteor Shower, which never seems to disappoint, is scheduled for its next major debut on the mornings of Thursday, August 12 and Friday the 13. The nighttime temperatures will be tolerable; it’s vacation time, and unlike last year when the bright gibbous moon hid many of the fainter meteors, it will not even be a consideration in 2010. An extremely thin crescent moon sets about 8:45 p.m. on August 11 and 9:15 p.m. on the 12, several hours before serious observations should commence. If you’ve never witnessed a meteor shower like the Perseids, then you are in for a real treat. It is analogous to fireworks, only of the celestial variety. Streaks of light caused by the dross from a comet’s tail will dash across the inky sky, with an occasional brilliant fireball burning its impressions into your mind as well as on your retina. As quickly as they are there, making the air glow, 70 miles or so above the Earth’s surface, they are gone. A night with Perseid meteors is always a night well spent; but don’t forget to dress warmly, snuggle within the confines of a light sleeping bag, carry a thermos with a caffeinated warm drink, and place plastic ground tarps under and over your sleeping gear to keep it safe from the dew. If you start observing around midnight, face northeast and view overhead, usually the darkest part of the sky. Perseid meteors will appear to fan away from an area of the sky near the border between Perseus and Cassiopeia. Many Perseids leave residual wakes and trains of glowing air after the initial meteor phenomenon ends, some persisting for as long as 10 to 20 seconds or more. The farther away you are from the detriments of light pollution, the more meteors you will see, but 30 to 60 meteors per hour from a rural locale represent realistic rates. Much success!

730 AUGUST 15, 2010: "Gate To Nowhere" Going Somewhere: There is a picture that has received wide attention on the internet and has been sent to me on several occasions for my analysis. It is titled “Sunset at the North Pole” and features a low orangey sun glinting lazily off calm waters in the foreground. The sun is centered above a distant mountainous landscape. Above the sun there is a huge waxing crescent moon, also reflecting off the water. The image is so mesmerizing that the first time I saw it I wondered how it could have been captured with such a dynamic range of lighting. I remembered shaking my head back into reality, recalling that the sun and the moon are almost exactly the same angular size in the sky and unlike Antarctica, there is no landmass at the North Pole. The moon’s orbital path would have placed Luna nearly parallel to the horizon, so it should have been seen either to the right or left of the sun. The picture was a fake, albeit beautiful. It had appeared as the frontispiece of a 2009 calendar published by Zazzle—http://www.zazzle.com/ inganielsen/—featuring the digital artwork of 27 year old Hamburg, Germany native, Inga Nielsen. Her scenes are highlighted on her “Gate to Nowhere” homepage, http://www.gatetonowhere.de/, which I strongly recommend visiting, and where through Zazzle, many other products featuring her artwork can be found. Although Ms. Nielsen’s tastes tend toward the fanciful, her images have a quality of reality that stirs the emotions and beckons the viewer to want to step into the scene. In addition, the astronomy which appears throughout many of her works is correctly portrayed and undoubtedly can be attributable to her pursuit of a degree in astrophysics and geophysics. Inga Nielsen’s art is fully downloadable, just don’t be like the fool who turned a beautiful image called “Hideaway” into “Sunset at the North Pole” and tried to mislead millions of internet viewers.

731 AUGUST 22, 2010: Webb to Replace Hubble: It has now been 20 years since the Hubble Space Telescope went into operation. Its hobbled start with its nearsighted optics, and then its spectacular fix showed the worst and the best of the US space program. Hubble discovered an accelerating universe composed mostly of things that don’t interact with what we see, called dark energy and dark matter. They were not even considerations of the scientific think tanks that envisioned Hubble’s legacy. Now as Hubble’s useful life ebbs to an end, a new space telescope, scheduled for launch in 2014, is taking shape. The James Webb Space Telescope is not only big, 259 inches across (Hubble mirror is 94.5 inches in diameter), but it will be placed 932,000 miles from Earth, where the combined pull of the sun’s and the Earth’s gravity will drag Webb along with an orbital period the same as the Earth. Unlike Hubble, there will be no room for error. If the telescope fails to deploy properly or its optics are defective, there will be no deep space rescue to resolve the crisis. Everything must work the first time and every time. The pictures returned by Webb will be different too. Instead of looking at the visible and the near infrared parts of the electromagnetic (light) spectrum, Webb will have the capability of seeing deeply into the heat sensing infrared. This is because the universe is expanding, and the farther we peer into space, the faster the universe is rushing away from us. This shifts the light from objects seen normally in the visible and the ultraviolet parts of the spectrum into the infrared. Webb will gaze into the Dark Ages of the universe, when the first stars were being born. Astronomers are confident that because of Webb’s 18 giant segmented gold mirrors, a sunshade the size of a tennis court to keep the telescope in the deep freeze, and the pristine environment of outer space, they will be able to realize their dream.

732 AUGUST 29, 2010: September Perseids: Will They Surprise?: It was September 13, 1969 and my friends and I were pulling an all-nighter watching meteors at Pulpit Rock, a 1500 foot ridge 20 miles to the WSW of Allentown, PA. It was the macro sky and meteors that had accelerated my interest in astronomy years earlier. I had first observed the August Perseid Meteor Shower with my cousin John back in 1964. Now it was mid-September on a radiantly clear, fall-like night. We normally observed from dusk to dawn, some of us falling asleep along the way, but it was great fun, especially when the unexpected occurred, like the appearance of a brilliant fireball, scorching itself against the starry vault. After midnight it became quite obvious to me that something odd was happening in the sky. My companions, Mark Adams and Kenneth Fite, were already feeling the crush of the previous day’s activities, but pretty soon they were fully awake too! There were meteors radiating from the constellation of Perseus the Hero, but they were southeast of the August radiant. There weren’t many at first, because trees blocked our view of the star pattern, but it was obvious that organized meteor activity was taking place. As the hours ticked away and Perseus rose higher into the heavens, meteor numbers increased. Between 2-3:00 a.m. we counted 10 related events. We had rediscovered the September Perseids, a little known and studied minor shower that had no cometary association, but occasionally acted up producing a dozen or more meteors per hour. In 2008 the September Perseids surprised astronomers again, producing 25 meteors equal to or brighter than Jupiter in a four hour period. Now that I’m newly retired with a little more time, I’m hoping to repeat a four decade-old memory and see them again on maximum morning, Thursday, September 9. I am also hoping, maybe even praying, that my summons to jury duty on September 7 won’t interfere.