Monday, January 31, 2005

21-March-2002: Home@Walnut (M41 in the urban sky)

I'm living near where the spot lights are flooding in the sky recently.

Yesterday night, after searching the comet I-Z (failed), I begin to find a DSO which came near my window.

I used my 70mm refractor to find it, and after looking at the star chart, I found it. It's easy in dark sky but it's not so easy to find it in the urban area. The first time my FoV covered that area which I felt confident in, but there seems nothing there.

I remembered that I read an article from a famous amateur in sci.astro.amateur saying that some objects will not be visible in the eyepiece if you just sweep across the field.

So, I stopped for a while, spend some time to look at the area which I felt confident.

After 2 or 3 seconds, the open cluster revealed itself from invisibility! I called my wife in and showed it to her, she could see if after a while too.

Then, I setup the 200mm and tried to catch it again.

The starting point was Sirius. At 62x, the sky was dark and the Sirius looked real good. I called my wife in and she said it looked like a big diamond. She told me that there's a dark thing in the center of the star, it's an indicator of two things: good collimation, focus was bad. I asked her to focus it again, and the black spot disappeared.

I then searched for M41 again. With the experience just gained with the 70mm, M41 was found much quicker. The number of stars in the open cluster was much more than with the 70mm, and I could see it immediately. Again, I asked my wife in and shared the view with her. She said there were so many stars, with different colors.

Personally, I found the view of M41 superior in a dark sky with my 70mm than the view of it at the urban center with the 200mm. Aperture is not everything, darker sky somehow and sometimes can play a more important role.

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