Friday, August 27, 2010

A Night in the Milky Way, August 26-27, 2010

I have so much to post about last night, and all of a sudden my computer doesn't want to cooperate with me, so I will post the two that I have sort of ready.

I hadn’t had a really nice night for astronomy since the weekend of the Perseids, and hadn’t had a night alone with the cosmos for at least a month. Last night I woke up just before sunset, and went out to see if the sky was clear. I stayed out until just before sunrise.

The sky was clear as the orange glow to the west gradually faded to ever darker shades of blue. Venus wasn’t very high, it’s fat crescent sinking fast. Mars and then Saturn revealed themselves to my observant eyes, teasingly reminding me of their nights of glory, with longer, deeper darkness, and bitterly cold winds to bear. Those two frozen worlds shunned the summer night, and disappeared from sight.

Chilly for August, the mosquitoes stayed away. Not a single buzz in my ear under my hoodie. A few crickets chirping, airplanes descending, and coyotes baying at trains off in the distance were the only sounds I heard.

The Moon was up with the night, then Jupiter and Uranus too. But their westward journey would be many hours, while others would not, so I searched the Scorpion, the Archer, and mighty Hercules for spherical stellar globs, ancient miniature galaxies, yet part of our own. By the hundreds of thousands, starlight filled my eye, well received on it’s journey afar. Among these timeless stars, a Ring was expanding, cast off from an exhausted, far away star.

Four dots with a giant, dancing away, and a storm raging larger than Earth. On our beaten up rock, watch the sunlight retreat as she moves to the east, waning nearly a fortnight. Nearby is Herschel’s grayish-blue disk, two hours sunlight distant.

Dazzling stars, finding their place in the Milky Way. Clustered together, by the dozens and scores, some will last much longer than others.

And here comes the Big Dog, to herald the Sun, my quiet night of observing is done.

It was an awesome night, starting with the planets and the Moon, moving on to a string of Messier globulars, keeping track of the sunset on the Sea of Crises and the Galilean Moons around Jupiter, ending with quite a few open clusters, and of course one last look at the Moon and Jupiter.

For a nearly full Moon, I had quite an observing list, in order observed:

M80- Very bright.
M 4
M13- Better than M22.
M92- First time observed! Bright core.
M 9- First time observed. Kind of washed out by LP.
M 6
M54- Really small, really faint.
Hyades Cluster
Double Cluster
M34- First time observed. Nice!

Jupiter & the Galilean Moons, August 26-27, 2010

When I first started observing telescopically two summers ago, Jupiter was my favorite target. On more than 40 clear nights I tracked the progress of the Galilean Moons by sketching them as many times as I could each night. Eventually I was able to tell them apart by comparing my sketches to their known orbital periods, and could roughly predict where each Moon would be each night.

Since discovering digital technology, I have sadly given up sketching Jupiter (the only thing I ever sketched at the eyepiece). For old time's sake, I sketched out the positions of the Moons last night when I first observed Jupiter, but subsequently switched the digitally capturing them. It may be my loss as an observer, but it also fun to look back through the pictures and video, find the best stuff, and put them all together. This was most of my night observing the Jovian system:

Monday, August 16, 2010

Dual Shadow Transits on Jupiter

Friday morning, August 13, 2010, the shadows of Ganymede and Io were falling on the disk of Jupiter during the morning twilight. From the calculations of Curt Renz, I knew that Io's shadow would appear at 5:09 AM Chicago time. I wanted to view this, and if I could, to get images. I have had a cheap Meade Lunar & Planetary CCD imaging system for awhile now, but have not used it much. I brought it for the Perseid peak to try to capture the dual shadow transits on Jupiter Friday morning. The results are not great, but over the course of nearly four hours I recorded the motions of the Galilean Satellites.