Tuesday, July 6, 2010

Pluto is in Sagittarius

This week Spaceweather.com posted this Event: Pluto is transiting Barnard 92, an inky black cloud of dust in the constellation Sagittarius. "Pluto was faint but very obvious against the dark background: image." I might get a chance to set up and observe while the dwarf planet is in Sagittarius. If I'm lucky, some time this week between the clouds.

Astronomy Magazine describes observing this area of the sky:
On warm summer nights, it's irresistible to gaze toward the center of our galaxy within the great constellation Sagittarius the Archer. Loaded with star clouds, clusters, and bright and dark nebulae, the constellation could easily keep a telescopic observer busy for an entire observing season. Before diving in with the telescope, though, it's worth spending some time discussing what Sagittarius offers unaided eyes. The most prominent pattern in the constellation is the Teapot, an asterism of eight 2nd- and 3rd-magnitude stars that resembles its namesake. The Teapot's stars range in distance from 80 to 300 light-years. At the top of the Teapot is Lambda (λ) Sagittarii, the asterism's closest star, while Delta (δ) Sagittarii is its most distant and nearly 20 times as luminous as Lambda. It's easy to think of the Teapot as occupying most of the constellation's area, but in fact, Sagittarius is several times larger.

The Tea pot (asterisim) is a sign post to the center of the galaxy.
A spectacular view in binoculars is the Sagittarius Star Clouds - The part of the Milky Way near the constellation Sagittarius ("the Teapot") reveals the richest detail in the night sky. It teems with interesting objects, including the Lagoon, Swan, and Eagle Nebulas, the M24 Star Cloud, and a wealth of open clusters. Use a star chart to help identify them.

Sagittarius is the Center for Summer Observing
If you are in a dark sky location, you can also identify it easily in binoculars by starting at the M24 "Star Cloud" north of Lambda Sagittari (the teapot lid star) and simply scan north. This nebula is bright enough to even cut through moderately light polluted skies with ease, but don't expect to see it when the Moon is nearby. You'll enjoy the rich star fields combined with an interesting nebula in binoculars, while telescopes will easily begin resolution of interior stars.

There is lots to see, I can make it a longer night [if the clouds break] and observe all the following in the telescope: NGC 6445, M23 (NGC 6494), M20 (NGC 6514), Barnard 86, NGC 6520, NGC 6522, M8 (NGC 6523), M21 (NGC 6531), NGC 6563, M24 (IC 4715), M18 (NGC 6613), M17 (NGC 6618), M28 (NGC 6626), M69 (NGC 6637), M25 (IC 4725), NGC 6645, M22 (NGC 6656), M70 (NGC 6681), M54 (NGC 6715), NGC 6723, M55 (NGC 6809), NGC 6818, NGC 6822, M75 (NGC 6864)

Tonight, The Earth is at aphelion. Aphelion is the point in the Earth's orbit when it's farthest from the Sun. Today Earth is 1.017 A.U. or 94.5 million miles from the Sun. The Tilt of the home planet brings our Northern Hemisphere these hot summer days.

Thursday night, Draw a line from bright Arcturus high in the southwest to bright Vega high in the east. A third of the way along this line is dim Corona Borealis, the Northern Crown, with its one moderately bright star, Alphecca, sometimes also called Gemma. Two thirds of the way along the line is the dim Keystone of Hercules.

Friday, Regulus is about 1° lower left of brilliant Venus in the west as twilight fades. Look carefully; Venus is 150 times brighter!

News from the Net:
All-Sky Stunner from Planck
New Satellite for Monitoring Space Debris To Launch

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