by Albert Highe
Equipment: 12.5" f/5 ultralight.
Thinking I'd arrive at Dinosaur Point early, I pulled in around 4PM to find the parking lot seemingly full of cars and scopes already set up. The lot was actually mostly empty. It's just that I've come to expect only a few people at this site, and being one of the first to arrive. Its nice to see that Dinosaur Point has been "discovered." I'd estimate that at least 40 scopes showed up. As usual, a few boaters came up the ramp as dusk approached and drove off. The ranger did not come by - no fees collected.
A couple of barbecues were lit and many people ate their dinners at the picnic tables alongside the peaceful lake, a few steps from our scopes. Quite a convenient set-up.
The sky contained a lot of high thin clouds that mostly dissipated after Sundown. However, transparency was poor by Dino's standards. The moisture and high thin haze scattered light, brightening the skies at Dino more than I've seen before. The conditions probably reduced the ability to see faint fuzzies by approximately a magnitude. Still, it was an excellent night and I found approximately 40 new galaxies. Most were in the 11-13 magnitude range, although I did bag one of 14th magnitude.
By 7:00PM, the temperature dropped to 60F with 61% RH. Conditions stayed warm and dry until at least 1:30AM, when I left. The temperature was in the mid-50's for most of the night while the humidity climbed to the low 80's - just low enough to prevent dew from forming. Scope and charts stayed dry. The wind was dead calm most of the time.
With such a large crowd, I spent more time wandering around and sharing views than usual. This activity proved to offer a great reward - Thor's Helmet in a 25". I first observed Thor's Helmet last month. I discovered it by following my usual observing regimen - finding everything in Sky Atlas 2K. NGC2359 and IC468, which are part of Thor's Helmet, are represented by two small adjacent symbols on page 12, lying inconspicuously between M47 and Sirius in Canis Major - easy to overlook. However, by being systematic, I looked at them and found a very interesting region of nebulosity, much brighter than I expected.
After I returned home from observing last month, I looked up these objects on the internet and learned that they form the well-known (well, not to me at the time) Thor's Helmet. I returned to study it again last night at Dino now that I had seen images of this region. Also, I took the time to use my OIII filter. The view, even in the 12.5", is remarkable. This region of nebulosity responds extremely well to the OIII. The improvement with the filter is better than just about any object I've seen.
However, Jon Ruyle had his 25" f/5 set up across from me. I hadn't looked through a giant scope in quite a while and asked him if I could mooch a view. After taking in Orion .... Yeah, I spent a long time there. What a view!
Well, after taking in Orion, we pointed his scope at Thor's Helmet. Without the OIII filter, it wasn't all that impressive. But with the OIII filter at 115X - you've got to see this!!! There is a very large circle of nebulosity that is clearly a large bubble. The outer thin shell is clearly visible along with other fine variations of intensity across its surface. Tangent to, and on either side of this bubble, are two narrow lines of nebulosity. One is much brighter than the other and is the one typically seen without the OIII filter. The filter brings out the second line, and in Jon's 25", a lot of other wisps of nebulosity nearby. Thanks Jon.
The other area of note is in the region of NGC3311. There are seven galaxies in one moderate-power field-of-view.
NGC3307 Mag 14.2, 1.0X0.4, the most difficult member
NGC3308 12.3, 1.8X1.4
NGC3309 11.0, 4.4X3.1, a very close pair with
NGC3311 10.9, 4.0X3.6
NGC3312 11.8, 3.4X1.1
NGC3314 12.8, 1.5X0.8
NGC3316 12.6, 1.4X1.2
And just outside the f.o.v. is NGC3305 at 12.9, 1.1X1.0.
By the time I left at 1:30AM, about half the pack had left. A wonderful night of great food, great views, and swapping equipment - all that one expects from a large star party and what one has come to expect from TAC. It felt like the observing season for 2001 had officially begun.