Early summer evenings don’t offer much in terms of pristine, dark skies. The late sunsets, long twilights, and hungry mosquitoes scheme to prevent us from having a relaxing evening underneath the stars.
However, these few weeks offer an excellent opportunity to observe the marvels present in our own neighborhood. So grab the bug spray, a lawn chair, and your telescope (or decent pair of binoculars), and spend the month getting re-acquainted with your neighbors in the solar-system.
What’s New
The Moon puts on a grand show this month. The first week of July, you’ll be able to see the crescent Moon right after sunset in the southwestern sky. To the left of the moon, two bright objects will dominate the twilight sky – the planet Jupiter and the brilliant star Spica. Jupiter is the brighter of the two, and even a modest pair of binoculars will show the four brightest moons scattered around the planet’s disk.
Time-lapse movie of Jupiter and its four bright moons on the night of 2-3 July, 2006
Early morning on the 20th, the Moon will pass in front of the Pleiades star cluster (M-45). Stars will wink out as the Moon passes in front of them, then suddenly re-appear as the Moon moves away minutes or hours later. Eastern North America is in the best position to see this event
The most exciting event this month occurs on the night of July 2-3, when asteroid 2004XP14 will fly by the Earth. If you observe from the eastern US and have a six-inch or larger telescope, you will be able to see this mountain-sized rock as it moves through the northeastern sky. S&T has posted three star charts to help you locate the asteroid: Chart A (190 KB PDF), Chart B (170 KB PDF), and Chart C (140 KB PDF).
What’s Old
July is a month full of globular cluster opportunities that are available within an hour of the meridian at local midnight. Starting in Hercules, there is one of the most beautiful sights in the heavens, the famous globular M-13 - along with too often overlooked M-92.
The great globular cluster in Hercules, M-13. Click to embiggenate.
Stargazers also often forget to nudge their scopes slightly to the northeast when observing M-13 to see the faint spiral galaxy NGC-6207. Both can be seen in this image, which is simlar to the field of view in an eyepiece that gives a true field of about 45 arcminutes.
Moving south into Ophiuchus, you can observe an abundance of globulars: M-12, -10, -14, -107, -9, -19, and -62. In the NGC catalog, there are NGC-6235, -6287, -6304, -6316, -6342, -6355, -6401, and -6426. Near M-9, there is also the small, bright globular NGC-6356. There is yet another in Libra, M-80, and about 1.5 degrees away from Antares in Scorpius is the glorious loose globular M-4.
Also in Scorpius are open clusters M-6 and M-7. Sagittarius offers M-23, another open cluster. These three are far enough south to require a darker southern horizon, something for which those living north of 40 degrees latitude often miss out. If you are one of those northerners, then make sure to take advantage of your slightly darker northern sky and inspect the famous Cat’s Eye planetary nebula (NGC-6543) in Draco. Also, while in Draco, take a glance at the carbon star UX Draconis, one of the reddest stars in the heavens.
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I truly appreciate these monthly “newsletters” Whats up! I have always been enthralled with the sky and what bright star is what! But never have the time to study any of it. (don’t think I’m intelligent enough to remember the terms)
Our skys are so clear! Being able to look up and see Jupiter has been exciting! With the binoculars I have I could see the moons of Jupiter! Awe inspiring!
Looking forward to the 20th! and “WHATS UP” in August.
You should experience the Northern lights up here!
Thanks, WSW. I’ll bet those cold, crystal-clear Wisconsin nights are great for northern lights!
Use those binoculars to scan the Milky Way, too. You’ll see tons of star clusters, rivers of nebulae, and even some brighter galaxies.
Happy skywatching!