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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'll need a detailed, large-scale sky atlas (set of charts). The standards are the little Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger and deeper Sky Atlas 2000.0 (stars to magnitude 8.5); and the even larger 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 Sue French's new Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, the bigger Night Sky Observer's Guide by Kepple and Sanner, or the classic if dated Burnham's Celestial Handbook.
Can a computerized telescope replace charts? 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 is hidden in the glare of the Sun.
Venus (magnitude –4.0, in Aquarius) is the brilliant “Evening Star” shining in the southwest during and after dusk. It will continue to move a little higher each week all winter. In a telescope Venus is still a small gibbous disk, 14.5 arcseconds in diameter.
Mars (about magnitude –0.5, at the Leo-Virgo border) rises in the east around 9 p.m., far beneath Regulus and the Sickle of Leo. Mars is brightening rapidly now as it approaches Earth. It shines highest in the south, in best telescopic view, around 3 or 4 a.m. Mars has grown to 11½ arcseconds wide, on its way to 13.9″ when closest to Earth in early March.
Jupiter (magnitude –2.5, still at the Aries-Pisces border) shines highest in the south in early twilight, moves lower toward the southwest as evening advances, and sets in the west around midnight or 1 a.m. In a telescope Jupiter has shrunk to 40 arcseconds wide.
Saturn (magnitude +0.6, in Virgo) rises in the east around midnight and is high in the south in early dawn. Spica, a bit fainter at magnitude +1.0, is 7° to its right or upper right. Saturn's rings are now tilted a generous 15° from our line of sight.
Uranus (magnitude 5.9, near the Circlet of Pisces) is in the southwest right after dark.
Neptune (magnitude 7.9, at the Aquarius-Capricornus border) is disappearing into the glow of 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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