Friday, November 4, 2011

Weekend SkyWatcher's Forecast - November 5-6

Written by Tammy Plotner

Greetings, fellow SkyWatchers! With a lovely gibbous Moon taking over the sky, now is the time to really enjoy some "high power" observations. Are you ready? Then let's take a look at what's happening this weekend...

Saturday, November 5 - Today in 1906, a man named Fred Whipple was born. If that name doesn’t ring a bell for you – it should. Thanks to Dr. Whipple’s work we have a clearer understanding of the orbital mechanics of comets and their relation to meteoroid streams. Not only that, but he founded the SAO observatory in Arizona, discovered six comets, made invaluable contributions to research in the upper atmosphere, and was the first to call a comet a “dirty snowball.” His guess about the outgassing properties of comets was proved true when the first flyby of Comet Halley was made!

To honor Dr. Whipple a bit, let’s have a look at a beautiful optical pair/multiple system as we journey to the southernmost star in the “Circlet” – Kappa Piscium (RA 23 26 55.9553 - Dec +1 15 20.189) - the "k" symbol on our map.

Easily split in even binoculars, this lovely green and violet combination of stars may have once belonged to the Pleiades group. 5th magnitude Kappa is a chromium star – one with unusual spectral iron properties – which rotates completely in around 48 hours. It shows lines of uranium, and the possibility of a very rare element known as holmium. Both the uranium and osmium content could be the result of a supernova explosion in a nearby star. Enjoy this colorful pair tonight!

Now aim binoculars towards Gamma – the “Y” symbol on our chart. Gamma is a yellow-orange giant star located about 130 light years distant. Oddly enough for a giant, it only puts out about 61 times more light than our Sun – but with good reason… it’s currently fusing it’s core to carbon. Right now, it is waiting to become a white dwarf, but that’s not what distinguishes Gamma – it is its speed. Apparently Gamma came from outside our Milky Way Galaxy altogether! According to its low metal content and cyanogen-weak spectral signature, Gamma had to have originated outside the galactic disc and it is still traversing the sky at over three-quarters of a second of arc per year!

Sunday, November 6 - "Now that she's back in the atmosphere, with drops of Jupiter in her hair..." Oh! Hey, there! Come on over and have a seat. Yeah, I really like that "Train" song, too. While the Moon is putting the brakes on deep sky observing, why don't you take a look though the magnificent eye of the 9" TMB refractor of Dietmar Hager and we world-wide friends can spend a little quality time together with Jupiter. (For a 3D impression, just look at the above image and cross your eyes. Focus on the image you'll see in the center... and you'll see 3D!)

Here... You look through the eyepiece of a little telescope for awhile and I'll tell you some of the things we know about this giant planet.

What's that you say? Yes. Jupiter is big... Big enough to hold the mass of 1,000 Earths and about 1/10 the size of our Sun. Its a heavy-weight, too... But, believe it or not, Jupiter's density is only about 1/4 of that of Earth's. Scientists think this means the giant planet consists mostly of hydrogen and helium around a core of heavy elements. That means Jupiter more closely resembles a sun instead of a planet! Yeah... It's hot there, too. As a matter of fact, Jupiter is putting out twice as much heat as it receives from Sol. Near the core temperature may be about 43,000 degrees F (24,000 degrees C)... Even hotter than the surface of the Sun. Hot enough to get a burn? Darn right. Those subtle tones of red and brown are chemical reactions much like what happens when we humans get a sunburn.

I see you smiling in the dark. Are you starting to notice details Jupiter's cloud bands? Even a small telescope shows these areas called "zones". This is where chemicals have formed colorful layers of clouds at different heights. The white belts are made of crystals of frozen ammonia and they are positioned much higher than the dark belts. Of course, you know all about the "Great Red Spot", but sometimes it's pretty hard to see unless you know when to look. Jupiter makes a complete rotation in about 10 hours, so even if you can't see something right now - you can wait awhile and it will come around.

Speaking of coming around, did you notice how close one of Jupiter's moon is getting to the edge of the planet? Then keep watching because we're about to see a transit happen. Jupiter has at least 60 moons, but 4 of them are bright and very easy to see even in binoculars. They were discovered by Galileo, and that's why you'll sometimes hear them called the "galiean moons". When they zip around behind Jupiter in their orbit, it's called a occultation - but when they go in front of the planet from our point of view, it's called a transit. The really fun part is that you can not only see the little moon going across the surface, but a few minutes later? You can see the shadow, too! Here's a little bit of magic from another friend of ours named Sander Klieverik.

Click on image to open a new window and start animation.

Isn't that just the coolest? You're going to be hearing a lot about Sander's work here in the near future. In the meantime, why don't you keep practicing timing galiean events and seeing them? Here's a handy Jupiter Moon Tool, and Sander has also prepared a Jupiter Almanac as well!

"But tell me, did the wind sweep you off your feet? Did you finally get the chance to dance along the light of day... And head back to the Milky Way? And tell me, did Venus blow your mind? Was it everything you wanted to find? And did you miss me while you were looking for yourself out there?"

Now, quit bogarting that eyepiece... It's my turn!

Many thanks to the one and only Dietmar Hager, Jupiter Video courtesy of Northern Galactic and the up and coming Sander Klieverik's "AstronomyLive". Song lyrics - "Drops of Jupiter" are from the artist "Train" and thanks to Universe Today. Let's keep on rockin' the night!

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