Friday, October 4
Saturday, October 5
Sunday, October 6
Monday, October 7
Tuesday, October 8
Wednesday, October 9
Thursday, October 10
Friday, October 11
Saturday, October 12
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.
This is an outdoor nature hobby. 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 guide to 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 once you know your way around, the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.
You'll also want a good deep-sky guidebook, such as Sue French's 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 beloved if dated Burnham's Celestial Handbook.
Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability, which means heavy and expensive). As Terence Dickinson and Alan Dyer say in their invaluable 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."
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Mercury (magnitude –0.1) remains deep in the glow of sunset. About 30 minutes after sunset, use binoculars to look for it 20° lower right of Venus. Saturn (magnitude +0.7) glows 6° above Mercury early in the week, and a similar distance upper right of it by week's end.
Venus (magnitude –4.3) shines brightly in the southwest during dusk, gradually moving higher week by week. In a telescope it's still gibbous (60% sunlit) and 19 arcseconds tall.
Mars (magnitude 1.6, in Leo) rises around 3 a.m. It glows in the east in early dawn with Regulus below it. Compare their colors! The gap between them shrinks from 6° on the morning of October 5th to 2° on the morning of the 12th. They'll pass a bit less than 1° apart on the morning of the 15th.
In a telescope, Mars is still just a tiny blob 4.5 arcseconds wide.
Jupiter (magnitude –2.2, in Gemini) rises in the east-northeast around midnight. It blazes high in the southeast by early dawn. About 8° left of it are Castor and Pollux.
Uranus (magnitude 5.7, in Pisces) and Neptune (magnitude 7.8, in Aquarius) are high in the southeast and south, respectively, by 10 p.m. Finder charts for Uranus and Neptune. See also the October Sky & Telescope, page 50.
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 Daylight Time (EDT) equals Universal Time (also known as UT, UTC, or GMT) minus 4 hours.
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