Monday, January 18, 2010

Good things come to those who wait

Two years ago, my astronomy friend, Pierre, and I caught a glimpse of the Large Magellanic Cloud from our roadside astronomy center way at the south end of Bonaire. Pierre had previously seen the LMC while observing in Chile and Namibia, but he'd never spotted it from Bonaire. I had never seen the Large Magellanic Cloud before, period.

The LMC is only visible for a short time, here on Bonaire, because it is in the far southern sky and never gets very high above the horizon. The LMC is a nearby (160,000 light years away) galaxy and appears, here on Bonaire, as a barely detectable, light-ish patch in the sky. Big binoculars reveal some interesting details.

I didn't get to observe the LMC last year, although I watched for it. We never had crystal clear skies down by the horizon during the moonless periods of Jan. and Feb. By March it was too late.
So I've been watching the skies like a hawk this year. Last Wednesday dawned cold and rainy, but cleared nicely in the afternoon. Visiting New Jersey friend, Bill Heatley, and I trekked out to the south end, and lo and behold, the sky was awesome for a couple of hours. With the 20x80 binoculars, I observed things, like the running man nebula and the flame nebula in Orion, that I had only seen in pictures before that night.

The LMC was visible too, and easier to see than it had been two years ago. We could just barely hold it with direct vision, and could pick it out pretty readily with averted vision. As soon as I was able to observe the LMC, I wanted to get a picture of it. But alas, I had left the cameras at home. So we had a wonderful time simply cruising the sky with the binoculars and left with only great memories of a stellar evening.

But, when the evening skies looked pretty clear last night, I zoomed down south with my trusty camera, 85mm lens, and tripod. I shot more than 150 six second long exposures at F1.8 and ISO 1600; and had Deep Sky Stacker combine the best 60% of them. Clouds and haze kept popping up in the individual images, so DSS was the fastest way to select the better ones. I'm happy with the results, but I'll no doubt keep fooling around with the image from time to time.

The LMC isn't centered in this full frame image, but in a way that is good, because it shows that the large diffuse light-ish region surrounding the center of the galaxy is not the result of vignetting in the lens. The LMC is really that big.

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