Friday, April 22
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Friday, April 29
Saturday, April 30
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, Venus, Mars, and Jupiter are deep in the bright glow of dawn. Venus is the least low and by far the brightest. Use binoculars 20 or 30 minutes before sunrise to look lower left of Venus for Mercury, which is fading daily. Farther lower left is tiny Mars, even fainter. And farther lower left still is Jupiter. Jupiter becomes a little higher and less difficult each morning; it will pass Mars on May 1st.Saturn (magnitude +0.5, in Virgo) is the only planet anywhere in good view now. Look for it glowing in the southeast as the stars come out, with Spica down below it and bright Arcturus far to its left. Saturn rises higher in the southeast after dark and shines highest in the south around 11 or midnight daylight saving time.
In a telescope, Saturn's rings have narrowed slightly in the last few months to 8° from edge on. See how many of Saturn's satellites you can identify in your scope using our Saturn's Moons tracker. Saturn's months-old northern-hemisphere white spot has spread into a faded, double light band all the way around the planet.
Only about 2° from Saturn is fainter Gamma Virginis (Porrima), a fine, close telescopic binary star with a current separation of 1.7 arcseconds. Use high power, and hope for good seeing. See article in the April Sky & Telescope, page 56.
Uranus is deep in the dawn, in the background of Venus but too faint to see.
Neptune (magnitude 7.9, in Aquarius) is low in the east-southeast just before dawn's first light.
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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