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The Griffith Public Star Party of August 30th, 2014

A report by

David Nakamoto

The temperature was warm all night. Clouds covered over part of the sky to the north and threatened to invade the rest, but stayed away from the southern sky. Thanks to a poor attempt at alignment and computer initialization, both tracking and slewing were off by a considerable degree, affecting how well the computer/mount combination could center objects. Also, it didn’t help that I was picking targets in widely scattered portions of the sky. There was some light haze, and a thin crescent moon, but nothing too serious. So around 7:20PM I started setting up my 10-inch aperture f/4.5 Newtonian and Orion G3 camera for a night of deep sky objects. Since this is the only way to actually see more than a faint fuzzy patch of light, I dedicated myself to those rather than give views of the Moon and planets. People of all ages appreciated and liked my efforts, and had many good questions about just about everything. But the crowd this night seemed to be less than usual, especially for the last weekend of summer. Perhaps a large attendance at the Greek theater, perhaps many people left town?

At around 8:00PM or so my first target was the Lagoon nebula M8, but for some reason I couldn’t see anything on the 1-second 2x2 binned search images, even after I had synced the computer’s position with lambda Sagittarii.   Same with the Trifid nebula, M20, so I went to an old friend, M-22. Tracking problems limited the exposure to 10 seconds, but the final processed image isn’t too bad. I was surprised that there wasn’t more glow in the image due to the lights of the observatory. What I like are the star colors, which are pastels as usual except for the rare intensely red carbon stars.

 image001

 

At 8:35 PM my next target was Pluto, which was 4° northeast of M22. Since I knew it was going to look like any other 14th magnitude star, I needed the help of Starry Night Pro to identify its exact location relative to the fixed stars. I noticed a curve of six stars in the shape of a snake just east of Pluto, then there were two stars below Pluto west of that. Then I noticed a faint but clearly discernible star above that pair in my image . . . and realized I was looking at Pluto ! This was another 10-second exposure. Pluto is identified by the white arrow. This is the first time I had looked at Pluto.

image002 

I was nice retelling the story of how Clyde Tombaugh recognized the star-like Pluto from the real stars on those photographic plates. As you can see, that is the Big Problem with trying to see Pluto. And to me Pluto is still the last planet discovered. I don’t think astrophysicists should define what a planet it, and then come up with a silly definition that denies calling the hundreds of bodies we’ve discovered around other stars “planets.” That’s one of the plus sides to doing public outreach. J

The next day I verified the shot by going to the STScI image archives. The matchup was precise and perfect !

M-51 the Whirlpool galaxy and M57 the Ring nebula were my targets at 9:20PM and 9:32PM respectively. M51 just did show its spiral arms, but otherwise the image was not a keeper. I do remember being a little amazed that, when slewing to M51’s location, I suddenly saw a fuzzy star, using the 1-second 2x2 binned imaging that I employ to see where the telescope is aiming at. It occurred to me that I was looking at the core of M51, although the location of the point where the telescope was aiming at on Starry Night Pro showed I wasn’t close. I increased the exposure to 10 seconds and saw the characteristic spiral arms ! Not as much drama with M57; even with a 1-second 2x2 binned image it clearly showed its donut shape. And the final image showed too much trailing.

Then around 9:45PM I tried to hunt for Neptune but soon realized that my pointing was so off when I did such large slews that I was hopelessly lost, with no bright stars to help me. And my setup would not allow for enough magnification to show it anyways, so I hunted down the stars around the head of Pegasus and homed in on M15, but I was in for another surprise. Because there, in the 1-second 2x2 binned image, the globular clearly was seen, with its stellar core AND some of its stars were resolved ! It formed a nice contrast with M22. Fortunately I was saving these images for later display so I could just flip back and forth to show the different objects. This is another 10-second exposure.

 image003

I then realized I had imaged pretty much every major class of deep sky object except for open clusters and diffuse nebula. Since it was past 10:00PM and time was running out, I decided to try for one of the finest opens in the sky, M11. It took some doing, including starting the search back to Altair, but after some time I finally got it in my sights. Even with the search mode 1-second 2x2 binned images the clusters stars were apparent, and with a 10 second exposure this showed up:

image004 

Actually, and for the first time, I see a thick-bodied moth here !

So a very successful night ! My first look at Pluto, and only my third look at M15. I don’t think the public misses not looking through a telescope, once you explain how faint and undefined the objects would appear. With every other scope on the field going visual, it’s worthwhile to offer a better view of other, less known objects.

And it’s fun to pretend that this is the way the pros do it . . . which isn’t that far from the truth.

Happy Observing !

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