November 13, 2012

Star Hopping

Though temperatures are now dipping toward the wintery end of the scale, this past Saturday was as lovely a late fall day as you could imagine. The sun (which has mostly been in hiding these days), was out in full splendor, and warmed things up from the low-40s, to a downright balmy 70 degrees. Though I'd seen this optimistic forecast, when I left the house that morning to head in to my job at the post office, I was decked out in a fleecy jacket over the top of a long black turtle-neck sweater. A few minutes into my route I was a lot more than just comfortably toasty in the LLV, and wished I'd worn a short-sleeve shirt underneath. Even with the heat off and the windows down, I was sweating enough to ruin the gas receipt I had put in my back pants pocket...much to the chagrin of the postmaster. Still, I earned some brownie points by completing my delivery in 10 hours: just 1 hour over the route's official evaluation. For a newbie such as myself, that is not so bad. Right now, as I'm learning the ins and outs of casing and delivering the route, I'm paid by the hour, but in a month this grace period will end and I'll be paid for the evaluated 9 hours, whether the route takes me 6 or...heaven forbid...16. It's to my benefit to learn quickly and work efficiently.

The warm clear day turned into a relatively warm clear night: perfect for dragging out binoculars (which we won in a recent BRAS raffle), and a new (borrowed) Dobsonian telescope for some exploring. We brought everything onto the front porch, which offers a nice tree-framed view of the eastern sky, and immediately set our sights on the night's dominant attraction.

Jupiter was perfectly situated above the trees and far outshone it's Tauran neighbors. In a good pair of binoculars, the giant planet and its moons (three of which were visible that night), are a wondrous sight. I should've had no trouble homing in on the celestial beacon with my scope, but unfortunately this particular piece of equipment isn't equipped with a telrad or even a finder. My only option was to sight down the tube and hope to get close enough that slight searching movements while looking through eyepiece would be necessary to locate my target. It took me a couple tries...and a little help with a laser pointer...but was well worth the effort. With an increase in magnification, I was able to pick out three distinct bands of red belting the planet's tangerine disc--the most I'd seen previously had been two.

Later, we took turns checking out a few open star clusters through the binocs. Open clusters often cover a wide enough swath of sky that they are most beautiful under minimal magnification, and with binoculars, you get the added bonus of being able to look at objects with both eyes, which makes them appear all the more dimensional.

The Pleiades were, of course, spectacular. After seeing this cluster for the first time from the back seat of my parent's car while on our way to visit my grandparents in North Dakota, my young imagination labeled it "the itsy-bitsy-teeny-weenie-yellow-polka-dot-bikini dipper." If you look closely, you'll probably agree that it does look like a bite-sized version of the other two utensil-themed asterisms. Before I knew the rudiments of star gazing...even before I learned it was possible to see the planets without a telescope the size of a skyscraper...the Pleiades became my favorite thing to watch for in the night-sky.  From then until now, all the photos I see of this famous cluster show the stars wrapped in gauzy sheets of blue nebulae. I was a bit disappointed when I learned that this is not visible without long-exposure photography, but even minus its provocative veil, the collection of stars glimmers like a cornucopia of diamonds.

Next up, was the Hyades: a striking V-shaped downstairs neighbor to the Pleiades, and home to the beautiful red giant Aldebaran. This cluster, which constitutes the head of Taurus the bull, is too spread out for a single view in binoculars, but it's fun to sweep back and forth over the region and marvel at how many stars pop into view.

The double cluster in the constellation Perseus was our final stop on the night's cluster tour. With averted vision, this starry region is ever-so-faintly visible, and Rob's trusty laser pointer made it even easier to locate in the binocs.

Now for the challenging stuff.

While looking at Jupiter earlier in the evening, we were only able to see three of the Galilean moons. I couldn't tell whether the 4th was hiding behind the planet, or (what I hoped) if it was passing in front and would be casting a shadow on Jupiter's colorful face (one of my favorite sights). I couldn't see a shadow, but just to make sure, I pulled out my laptop and consulted Stellarium. Unfortunately, the moon turned out to be behind Jupiter, but my interest was piqued when I noticed that Vesta, one of the largest and most massive asteroids in the asteroid belt (and recently visited by NASA's Dawn spacecraft), was cruising nearby. After a few back-and-forth recons between the binocs and my laptop, I decided it would be worthwhile to try to locate the speck of light reflecting off this "little" hunk of rock, and set about devising a route by which I could star hop to my chosen target.

Because I was without any sort of finder, I decided to start with something bright. I initially settled on the star at the tip of Taurus' lower horn, but finding this little point turned out to be a lot harder than I had anticipated. After a few failed attempts, I humbled myself, backed up to Aldebaran and followed the fuzzy green line cast by Rob's laser pointer down to the horn's tip.


One challenge I've had with star hopping is overcoming the urge to judge direction by what I see in the eyepiece. With a reflecting telescope, like the one I've been using, images appear upside down. When I move the telescope down, my brain "wants" to see the stars in the eyepiece move up (just like you'd see if you moved binoculars down), but instead the stars also move down. It's disorienting--a bit like trying to coordinate actions in a mirror--and going against hard-wired visual instincts takes some real mental determination.

Ok, so somehow I needed to get from the star on the upper left of this image, down to the asteroid in the lower right. I wanted to believe I could cover the distance in one fell swoop...or maybe two: stopping to check out that bright orange star about 2/3s of the way...but with every smidge of movement in the telescope making me seasick, I knew I'd have to take a more "scenic" route.


One thing I could already see in the field of view was a pretty little "string of beads" just above (or below, as it appeared in the eyepiece) the "tip-of-the-horn" star on which I'd situated. I decided to use this as a pointer to the next brightish star in the region, pictured on the far right of the image below...


 ...not so bad. Next, I noticed a similar, but much smaller, string of beads a ways below the bright star at which I'd just arrived (which, in the next image, is situated in the upper left). I couldn't see the new string in the eyepiece, but if I moved the scope slowly I hoped the little pattern would pop out of the starscape and bring me that much closer to the bright orange gem I'd been shooting for to begin with.


Made it!

From here it was an easy jog over to 119 Tau, and wow, what a beautiful red star it turned out to be. Rich and ruddy, it proved a great destination on its own...but I was after an asteroid...so, onward.

At least now I was in the neighborhood. Off to the lower right of 119 Tau's triangle, was a nearly straight line of stars capped on one end by a...well, to my mind, another "dipper" (they're everywhere it seems). The middle star of the dipper's handle (which looked like it was even a nice double), would be an ideal final jumping-off point for Vesta.


I got a little turned around here for some reason (just not used to the idea of working upside down I guess), and had to double back to 119 Tau a couple times before finally making it to my dipper, but the final hop was easy--as predicted.

When I sat down and studied the tiny speck that Stellarium was telling me was an asteroid, it was so unremarkable I had to go back and confirm the find a few times. Yup...it was Vesta alright. Just a tiny pinprick among more tiny pinpricks (and incidentally some impressively close double stars), I suppose the only way I'd really be able to feel satisfied about my find would be to track it over multiple nights and observe its movement with respect to the background. Alas, the following nights turned out to be cloudy, and though last night was finally clear again, temperatures had plunged into the 30s and I couldn't quite convince myself to head back out for a frigid observing session (what a wimp!).

Below is one of the many up-close images of Vesta taken by the Dawn spacecraft...much more impressive here!


1 comment:

  1. Methinks the lady's scope deserves a finder scope. :)

    Patrick

    ReplyDelete