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| If you have trouble viewing this newsletter, click here. Welcome again to our monthly newsletter with features on exciting celestial events, product reviews, tips & tricks, and a monthly sky calendar. We hope you enjoy it!
Highlights of the test report include: What We Like
"The freedom from worry over tangled or twisted wires is a real pleasure." "Operating a telescope with planetarium software on a computer, rather than the telescope's hand controller, gives you more information. You typically see a star chart showing where in the sky your scope is pointed and what other objects of interest might be nearby. Click on an object anywhere on the star chart, and off the scope goes to find it. And now, thanks to the BlueStar, this can happen without any worry of a connecting cable wrapping around the spinning scope. Hooray!" "[T]he BlueStar is a welcome turnkey solution to wireless control with laptop computers. It makes controlling the scope that much easier, with no intervening wires to trip over or tangle in the dark. Once you use the BlueStar you won't go back to wired astronomy again." Alan Dyer tested BluteStar with planetarium software other than Starry Night. BlueStar also works with Equinox version 6.1.2 and SkyChart III version 3.6.4 on the Mac. On Windows, it works with Cartes du Ciel version 2.7.6, Earth Centered Universe version 5.0, MaxIm DL version 4.53, MegaStar version 5.0.12, SkyMap Pro version 10, and TheSky Version 6. For the full review, see the March issue of Sky & Telescope on newsstands Feb. 6!
Riding the ecliptic near Regulus, Saturn is now prominent in the eastern evening sky as it heads to opposition February 10th. It will move slowly eastward, remaining the brightest star in Leo for the next two years. My first glimpse of the ringed planet through a friend’s telescope many years ago got me hooked on this hobby. Decades later, an encounter with Saturn on a steady night still takes my breath away. For the astro-photographer, a sharp and detailed image of Saturn is a prized and elusive catch. The ringed planet is a tough subject, revealing its treasures only in good conditions. The delicate disk bands and concentric minima in the B and C rings demand smooth, well-collimated optics and steady seeing. You also need to shoot at high magnification (a long effective focal length.) Saturn is small, spanning 45 arcseconds across the rings with a disk only 20 arcseconds in diameter. The Cassini division, a gap large enough for our moon to pass through, measures a scant arcsecond at best. This represents a speck about half the width of a red blood cell at the focal plane of a 4” f6 telescope! And the holy grail of Saturn imaging, the razor thin Encke gap, is much smaller. Though beyond the theoretical resolution of amateur scopes at a twentieth of an arcsecond, the very best images will show its location in the outer region of the A ring.
Saturn image courtesy Alan Friedman You might want to start by getting to know the seeing patterns from your observing location. Although Saturn will be at its brightest and largest around opposition, my backyard often yields the best images closer to the beginning or end of an apparition, when the planets reach the meridian just before dawn or shortly after dusk. This transitional time can offer brief periods of very steady air. Pre-dawn imaging is my favorite, quiet and peaceful, with plenty of time for the telescope to adapt to ambient temperature. An optical tube shedding heat in falling temperatures will not reach its potential, even if seeing conditions are great. To read the rest of this article, click here.
The poet Walt Whitman said, “I do not want the constellations any nearer, I know they are very well where they are.” But where are they, exactly? Constellations cover the sky. They also look flat - the stars all appear to be at the same distance. Appearances can be deceiving. We often refer to stars that look bright as “big,” and to their fainter companions as “small” stars. Are the bright ones really big? Are the faint ones actually small? Maybe the bright ones are closer and the fainter ones are farther away. Could it possibly be any other way? This is astronomy so the answer is “yes!” The distance to any celestial object is one of the most important things we can know about it. Without that single critical piece of data, everything else is almost meaningless. To understand the structure and organization of things celestial, we must know distances. The Hipparcos satellite has provided us with accurate and precise stellar distances, revolutionizing our picture of the universe. With Starry Night® it’s easy to find distances to individual stars. In doing so, we discover that some nearby stars are dim, and some bright stars are nearby. We also find that some of the brightest stars are very distant. When a distant star is also a bright star, it means the star is highly energetic; shining with hundreds or thousands of times the output of our Sun!
Figure 1—Some stars in the constellation Orion are much further away than others. At this time of year, a prominent constellation is Orion (figure 1). Orion hosts some of the brightest stars in Earth’s sky. Are they near or far? Table 1 tells us Orion’s stars lie at distances ranging from 243 to 1,360 light years. Rigel is brightest with a magnitude of 0.2. (Magnitude describes brightness. The lower the number, the brighter the star.) Rigel is 777 light years away and 51,000 times as bright as the Sun. Bellatrix is closer at 243 light years, fainter at magnitude 1.6, and only (!) 6,000 times as luminous as our Sun. To read the rest of this article, click here.
Very soon after the first telescope was invented, someone got the idea of mounting two telescopes side by side. We are, after all, creatures with two eyes, and tend to see more, and be more comfortable, when using both our eyes. Originally called “field glasses,” because of their military applications, they soon became adopted by nature lovers and amateur astronomers. In the late 19th century opticians started adding prisms to the design, resulting in more compact instruments with wider fields of view, and these instruments became known as “binoculars.”
Although binoculars do impart a mild three-dimensional view to nearby objects, when used for astronomy any such effect is an optical illusion, though sometimes a powerful one. The main advantage for an amateur astronomer in using binoculars, rather than a small handheld telescope, is that they are relatively easy to hold steady, and the images often seem brighter and more detailed because of the image processing which goes on in our brains when presented with two channels of information. Binoculars are extremely easy to use, and make scanning the night sky a pleasant intuitive activity, without the need to fiddle with finders, mounts, and eyepieces. In some ways, binoculars “don’t get no respect.” They’re often looked down on as the astronomical telescope’s poor relation. Yet they are a fine instrument in their own right, capable of observing objects which are simply too big to see properly in a telescope. One of the few astronomers to take binoculars seriously is Phil Harrington, whose book, Touring the Universe through Binoculars (Wiley), is the bible of binocular astronomy. They are also, to serious deep sky observers, an essential accessory in discovering starhopping paths through the stars. Many households already have a pair knocking around, or a reasonably good pair can be found at most sporting goods stores, so they are an inexpensive way to get started in exploring the sky. Numbers and more numbers Binoculars have a numbers game all their own. Different types are described by a pair of numbers with an “x” in between: 7x35, 10x50, 20x80, etc. The first number is the magnification: 7 times, 10 times, 20 times. The second number is the aperture of each half of the binocular in millimeters: 35 mm, 50 mm, 80 mm. They usually will be labeled with a field of view, either in degrees or how many feet they will show at 1000 yards (one of the strangest units I know of!) Another important number is their “eye relief,” which measures how far behind the eyepieces you must put your eyes to catch all the light. If you need to wear glasses while using binoculars, choose a pair with at least 15 mm eye relief. Finally, there is their “exit pupil,” the diameter of the cylinder of light coming out the back of the binoculars. This is calculated by dividing the aperture by the magnification; it’s a very important number, and I’ll say more about it later. To read the rest of this article, click here.
The FREE Starry Night® version 6.0.4 update is now available for download. The 6.0.4 Update includes:
If you already own Starry Night® version 6, it's easy to update to version 6.0.4 You must be connected to the Internet to receive the update. Download the installer by checking for updates.
Run the installer. When you launch Starry Night®, you will have version 6.0.4. Please be patient as there may be a number of people downloading at the same time.
Linda Fung
Last week favorably placed observers viewed a comet so brilliant that it could be seen with the naked eye in broad daylight, if the Sun was hidden behind the side of a house or even an outstretched hand.
Image © Robert McNaught, 2007 Comet McNaught, which was discovered last August by astronomer Robert McNaught at Australia’s Siding Spring Observatory, was one of the greatest comets in recent times. It evolved into a brilliant object as it swept past the Sun on Jan. 12, at a distance of just 15.9 million miles. Joe Rao |  | FEB 2007
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At Mag -1.5, almost everyone knows that Sirius is the brightest star in the night sky. You may notice it driving home from work: visible from early dusk, it sparkles brilliantly above the southern horizon. What many people don't realize is that Sirius is actually a double star. Sirius B is a challenging target, just 5" from Sirius and quite dim at Mag 8.5. It requires excellent optics but, if you can nail it, it's surely a feather in your cap. A little to the west of Sirius is a three star asterism, with the central star, V1, being an easy, pretty double separated by 17". M41 (also known as the Little Beehive) is a fine open cluster lying about 2,000 lightyears from the back of your eyeball. It has about 25 bright stars spattered across a field about the size of a full moon; in reality, they're spread over an area 20 lightyears in width. Bright enough to be sometimes visible to the naked eye (Aristotle is said to have noticed it around 325 B.C.) M41 is a good target for binos or low magnification in your scope. M46 and M47 are two open clusters just over 1° apart, making comparison very easy. Both are about 20 million years old but they're not connected in any way: M46 hangs in space about 5,000 lightyears distant, while M47 is closer at 1,700 lightyears. Of special interest is the planetary nebula that seems to be embedded near M46's center. Although the nebula is probably not actually part of the cluster (it simply lies along the same line of sight), it makes for a good opportunity to see two different types of deep sky object at the same time. In larger scopes, NGC 2360 (a.k.a. Caldwell 58) is a pleasing open cluster almost half way between M46 and Sirius. M93, the winter Butterfly Cluster, is a rich 6th Mag open cluster with about 80 visible stars. It's core resembles an arrowhead. While you're in the area take a look at k Puppis, a nice bright double. NGC 2362, the Mexican Jumping Star (a.k.a. Caldwell 64), and NGC 2354 are another pair of closely placed open clusters worth comparing. Finally, Mag 1.5 Adhara has a Mag 7.5 double just 7.5" due south. Adhara is a main sequence star that shines 9,000 times as brightly as our own sun. Good thing it's 432 lightyears away. Sean O'Dwyer | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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The Rosette Nebula Taken by Phillip Holmes using a STL-11000M camera on a G11 mount and a Televue NP101mm F5.4 telescope from his backyard in Rockhampton Australia.
PRIZES AND RULES: We would like to invite all Starry Night® users to send their quality astronomy photographs to be considered for use in our monthly newsletter.
Please read the following guidelines and see the submission e-mail address below.
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