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June 28, 2006
ANDOVER, Mass. — John Briggs, a visiting science instructor at Phillips Academy, is hosting several public open houses at the observatory in the school’s Gelb Science Center this summer for anyone interested in gazing at the night time stars. Each of the open houses will revolve around a specific theme, though the sessions will maintain an informal structure, giving attendees a chance to view various objects of interest.
Briggs, who’s an accomplished astronomer and a professional instrumentation engineer who has worked at observatories around the world, says the sessions generally will begin at approximately 9:00 p.m. Those who arrive early will have an opportunity to discuss the inner workings of the telescope as well as view a few bright stars that are visible before sunset. Inclement weather cancellations will be posted on the Web at www.andover.edu/summersession.
Following is a complete schedule for the open houses:
Friday June 30 (starting 8:30 p.m.)
"Saturn Watch"
See Saturn and its several rings before the planet slips low into evening twilight. The mysterious Saturnian moon, Titan, recently explored by visiting robotic spacecraft, will be visible. Weather and air turbulence permitting, our view with the Gelb telescope will show the rings nearly as clearly as this NASA image! (See Photo 1)
Wednesday, July 5 (starting 9:00 p.m.)
"Mars and Moon Watch"
See the gibbous Moon in evening twilight. Its cratered surface is illuminated by grazing sunlight, allowing a near three-dimensional perspective of lunar mountains that is not visible when our satellite appears full. Low in the west, Mars will be seen as a small orange disk. Come see how presently it shows a gibbous phase, just like the Moon.
Friday, July 7 (starting 9:00 p.m.)
"Jupiter Watch"
See our solar system's largest planet, which presently dominates the evening sky. Also visible will be the four moons discovered by Galileo: Io, Europa, Ganymede, and Castillo. At 9:34 PM, we'll see fast-moving Io disappear into alignment with the large, bright disk of Jupiter, and later, a beautiful phenomenon known as a shadow transit.
Wednesday, July 12 (starts 9:00 p.m.)
"Edge-on Galaxies"
Edge-on galaxies are among the most beautiful "cosmic" objects seen in the sky -- shining from distances of millions of light years. Tonight we will use Gelb Observatory's powerful electronic camera to capture images of such objects, which, amazingly, are shown in detail, even in short exposures through Andover's relatively bright suburban sky. Object M104, known as the Sombrero, is about 40 million light years distant. Another featured target (shown in Photo 2 a recent Gelb image) is NCG 4565, about 20 million light years away. (A small companion galaxy, “GSC 1990:788,” shines faintly in the lower right!)
Friday, July 14 (starts 9:00 p.m.)
"Seeing Star Clusters"
Star clusters are common in our Milky Way galaxy, and tonight we'll explore the two types: "open" and "globular." Open clusters are relatively young objects that have formed in the spiral arms of our galaxy. Globular clusters are older and very rare, orbiting beyond the plane of the Milky Way. Tonight we'll view many examples of both cluster types.
Wednesday, July 19 (starts 9:00 p.m.)
"Celestial Smoke Rings: The Planetary Nebulae"
Planetary nebulae are shells of gas blown off by certain stars as they pass through their long "life cycle." The objects thus have nothing to do with planets! But as they appear in the Gelb telescope, they're indeed reminiscent of the distant planets Uranus and Neptune -- looking like mysterious disks of greenish-blue light. Come see the brighter planetary nebulae -- favorite targets of all amateur astronomers -- and understand why they were named as they are, by the old-time astronomers of yesteryear. Seen here is Messier 97, the “Owl Nebula,” as recently imaged with the Gelb Telescope and its CCD digital camera.
Friday, July 21 (starting 9:00 p.m.)
"Colored Double Stars"
Almost 50 percent of the time, stars occur in pairs or clusters, not as isolated individuals like our Sun. We can see thousands of such pairs with the Gelb telescope. But among the most interesting are those pairs which happen to have very different stellar surface temperatures, which results in very different color. The most beautiful pairs shine in an orange-blue combination, the blue being the hotter star, the orange being the cooler. Come see famous examples of these pairs, including Alberio (beta Cygni) and Ras Algethi (alpha Herculis), presently well-placed in our evening sky. See stellar temperature with your own eyes!
Wednesday, July 26 (starts 9:00 p.m.)
"Galaxy Clusters"
Just as stars often form in clusters, so also do the vast stellar swarms we call galaxies. Come see the electronic camera at Gelb Observatory reveal such clusters in surprising detail, each picture taking only a few minutes to expose. The revolution in modern camera technology makes much of today's research possible. But also, it allows us to view cosmic objects from suburban places like Andover in ways unimaginable only a short time ago. (Stephan’s Quintet, shown in Photo 3 in a recent Gelb image, includes members 280 million light years away!)
Friday, July 28 (starts 9:00 p.m.)
"The Heart of the Milky Way"
The constellation Sagittarius lies toward the center of our own Milky Way Galaxy, some 30,000 light years away. Near this line-of-sight are many of the most spectacular celestial objects in the sky, including open and globular clusters, vast star clouds, and bright and dark nebulae, which are great gas clouds (often including star formation). Tonight we'll explore this remarkable region as it rises above our southeastern horizon. (Photo 4 is our recent image of the winter sky’s “Flame Nebula,” typical of many nebulae in the Milky Way.)
Wednesday, August. 2 (starts 9:00 p.m.)
"Barnard's Star and Selected Favorites"
Discovered photographically in 1916 by heroic American astronomer E. E. Barnard, Barnard's Star is a "red dwarf" too faint to see without a telescope. But it is remarkable because of its relative nearness to us (six light years), as well as because of its large apparent annual motion in the sky, relative to other stars. The only stars closer to us (besides the Sun) are those of the triple system alpha Centauri, which is in the southern sky and, thus, not visible from Andover's latitude. After seeing Barnard's Star tonight, we'll return to favorite targets of the summer.
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