Dog Days And Southern Crowns

Hello, astro-nuts!

The sunny summer weather is going to continue across central PA for the next several days. While that means my garden is going to be quite thirsty, it means that, for the most part, night skies will be clear for observing! I hope you all have a wonderful and safe 4th of July weekend; don't forget that fireworks aren't the only "oooh....ahhh"-worthy things in the night sky this weekend. The astronomy video has more details, and some ideas of what to look for before and after the fireworks on the 4th! Today I have several interesting tidbits to share with you!

Check This Out!

Don't forget about what will be in the night sky this Independence Day as you prepare for the fireworks shows, cookouts, or whatever else you have planned! Just before dawn on the 4th, look for Jupiter; it will look great this month through a telescope, and if you have binoculars you can find sideways planet Uranus nearby simply by placing Jupiter in the left side of your binocular view. On the right side you should see a pair of 6th-magnitude objects. The nearer one is a star while the other is Uranus. As it grows dark before the fireworks that evening, look for bright Venus in the west near Regulus in Leo, while Saturn and Mars will be nearby. The four were in a nearly perfect line two nights ago and not much will change by the evening of the 4th.

Solar Observers! Keep your solar scopes focused on sunspot 1084 which continues to hold its own as it continues to grow (now about twice the diameter of Earth!). Its magnetic fields are (for now) pretty sturdy so no flares are expected from it just yet, but this could change! In the mean time, SDO has captured some interesting Ultraviolet imagery of the quiet sunspot.

The Wide Field Imager at ESO's La Silla Observatory in Chile recently captured some stunning imagery of the star R Coronae Australis and the beautiful bluish nebula surrounding it. The star lies within one of the closest and impressive stellar nursery regions in the sky. The nebula is roughly 420 light-years away in the constellation Corona Australis (southern crown). R Coronae Australis is one of several young stars in the region that is still surrounded by the gas and dust from which it was formed. When the radiation is given off by this and other young stars in teh region, it interacts with the gas around it and is either reflected or re-emitted at various wavelengths, producing impressive colors and textures. The star and nebula are not naked-eye visible, but if you've got southern sky views and have a telescope, you can find its home constellation fairly near Sagittarius.

As I mentioned a few days ago, NASA has made the announcement of the newly revised dates for the final two shuttle launches. Discovery is now scheduled to launch at 4:33pm EDT on November 1st, while Endeavour's flight and the final shuttle flight in general will be February 26, 2011 at 4:19pm EDT. These adjustments were made, according to NASA, because important payload hardware would not be prepared in time for the previously planned September launch, and because that had to get moved to November (previous timeframe for Endeavour), the final launch had to be moved as well. Other launches and positioning of the sun made it necessary to push back to February. Keep in mind, these dates could change yet again!

Speaking of shuttle launches, a special ceremony is being held at the Lockheed Martin Space Systems Michoud Assembly Facility in New Orleans to celebrate thirty seven years of external tank deliveries, and of course the rollout of the the external tank for the final shuttle mission. The ceremony will be broadcast live on NASA TV on Thursday July 8th beginning at 8:45am eastern time. ET-138 was completed on June 25th and will be accompanied by a brass band and handkerchief-waving employees on its one-mile journey to the Michoud barge dock. After that comes the 900-mile trip to Kennedy Space Center.

And finally, you may start hearing that the "Dog Days of Summer" are starting soon--some of the hottest, driest days of the summer for the northern hemisphere. According to the Old Farmer's Almanac, they run from July 3rd to August 11th, while in Ancient Rome, these days were from July 24 through August 24. While there are many definitions or descriptions of what the Dog Days are, they actually have historical and astronomical significance. To the ancient Romans, the Dog Days were so called because back in their time, Sirius, the brightest night sky star, was rising at pretty much exactly same time as the sun this time of year, so it was thought that the bright dog star was somehow contributing to the period of hot, dry weather. Because of the gradual shift in the orientation of Earth's axis of rotation over time (precession of the equinoxes--the same reason that Polaris is now the north star, but in several thousand years, it will not be), we know that Sirius rises close to the same time as the sun this time of year, but the two are not nearly as close as they were in Ancient Roman times.

Keep your eyes to the sky and enjoy the view! ~Lisa C.

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