This Week's Sky at a Glance...........from Sky & Telescope Magazine

Friday, August 22
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  • How dark, or how light-polluted, is your sky? What's your naked-eye limiting magnitude for stars overhead? Find out using the Head of Draco or the Little Dipper map with Fred Schaaf's article in the August Sky & Telescope, page 48.

     

    Saturday, August 23

     

  • Last-quarter Moon (exact at 7:50 p.m. Eastern Daylight Time).
  • Jupiter's moon Io reappears out of eclipse from Jupiter's shadow around 9:18 p.m. EDT, just east of the planet. With a telescope, watch it gradually swell into view. For a listing of all events among Jupiter's moons this month, visible worldwide, see the August Sky & Telescope, page 58.
  • Jupiter's Great Red Spot should cross Jupiter's central meridian (the imaginary line down the center of the planet's disk from pole to pole) around 10:52 p.m. Pacific Daylight Time. The "red" spot appears very pale orange-tan. It should be visible for at least 50 minutes before and after in a good 4-inch telescope if the atmospheric seeing is sharp and steady, which it usually isn't. A light blue or green filter helps. For all Red Spot transit times, good worldwide, see our listing or applet online.

     

    Sunday, August 24

     

  • Jupiter's Red Spot transits around 9:43 p.m. Eastern Standard Time.

     

    Monday, August 25

     

  • Europa, the smallest of Jupiter's four Galilean moons, casts its tiny black shadow onto Jupiter from 8:13 to 10:58 p.m. EDT. Europa itself, meanwhile, departs from Jupiter's face at 8:56 p.m. EDT.

     

    Tuesday, August 26

     

  • With summer growing late, the Great Square of Pegasus is already up in the east after dark. Look for it balancing on one corner. It's a bit bigger than your fist held at arm's length.

     

    Wednesday, August 27

     

  • If you're up before the crack of dawn Thursday morning, take a look at the thin crescent Moon with binoculars. Can you spot the Beehive Cluster nearby? (As seen from the Americas.)

     

    Thursday, August 28

     

  • The red long-period variable star RT Sagittarii should be at maximum light (7th magnitude) this week.

     

    Friday, August 29

     

  • Vega is the bright summer star overhead soon after dark this week. Arcturus is the equally bright star in the west. A third of the way down from Vega to Arcturus is where you'll find the dim Keystone of Hercules. Two-thirds of the way down is the dim semicircle of Corona Borealis, with its one brighter star, Alphecca or Gemma.

     

    Saturday, August 30

     

  • New Moon (exact at 3:58 p.m. Eastern Daylight Time).
  • Jupiter's moon Io reappears out of eclipse from Jupiter's shadow around 11:13 p.m. EDT. In a telescope, watch it gradually swell into view just to Jupiter's east.