Early Sunday morning the asteroid 38 Leda occults an 8.7-magnitude star at the Virgo-Centaurus border for up to 31 seconds as seen from a track crossing from southern Mexico through Texas to Montana. Path map, finder charts, and other details.
Sky at a Glance is now an iPhone app! Put S&T SkyWeek on your iPhone, iPad, or iPod Touch and get the above listings anytime, anywhere with interactive sky maps! Tap a button to see the scene described, customized for your location worldwide. From there you can scroll the view all around the sky, zoom in or out, change to any time or date, and turn on animation. Now includes This Week's Planet Roundup below.
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Want to become a better amateur astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential magazine of astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).
Once you get a telescope, to put it to good use you must have a detailed, large-scale sky atlas (set of charts). The standards are the Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger Sky Atlas 2000.0 (stars to magnitude 8.5); and the even larger and deeper Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts effectively.
You'll also want a good deep-sky guidebook, such as Sky Atlas 2000.0 Companion by Strong and Sinnott, or the more detailed and descriptive Night Sky Observer's Guide by Kepple and Sanner, or the classic if dated Burnham's Celestial Handbook.
Can a computerized telescope take their place? I don't think so not for beginners, anyway, and especially not on mounts that are less than top-quality mechanically. As Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."
This Week's Planet Roundup
Mercury, Mars, and Neptune are hidden behind the glare of the Sun.
Venus (magnitude 4.2, in Sagittarius) shines as the "Morning Star" in the southeast just before and during dawn.
Jupiter (magnitude 2.1, at the Pisces-Cetus border) shines brightly in the west at dusk and sets roughly an hour after dark now. Get your telescope on it in late twilight while it's still high. Jupiter has shrunk to only 34 arcseconds wide, but try to keep watch on its South Equatorial Belt re-forming as long as you can.
Saturn (magnitude +0.5, in Virgo) rises around 9 p.m., but it's best seen in a telescope at its highest in the south around 2 or 3 a.m. Spica, slightly fainter, shines 9° below Saturn during evening, and left of it at dawn.
In a telescope, Saturn's new white spot has spread into a double streak far around the planet, as seen here. Saturn's rings are 10° from edge on. See how many of Saturn's satellites you can identify in your scope using our Saturn's Moons tracker.
Uranus (magnitude 5.9) is about 7° west (lower right) of Jupiter and disappearing into the evening twilight.
All descriptions that relate to your horizon including the words up, down, right, and left are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America. Eastern Standard Time (EST) equals Universal Time (also known as UT, UTC, or GMT) minus 5 hours.
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