It's been a long time since the last post, mostly because I haven't had much to write about: Let's get right to the excuses:
- It was a terrible year for weather; it seemed as if every imaging opportunity was clouded out
- My transition to computerized imaging that started the winter of 2017-2018 kind of slowed me down
- There was the mini-fiasco of the very late arriving Planewave 12.5" scope for the imaging platform. It didn't arrive until after the Nebraska Star Party and didn't get onto the mount until late August. Basically the delay pushed the timeline back about 6 months
- Unlike a lot of years, this year winter arrived early (November 1) and stayed. There was no pleasant, gradually cooling autumn to image through
So, now that that's out of the way, we can get on to catching up. After such a dismal year what could a person do other than double down on what seems at times to be a frustrating hobby? That's right: I am upgrading things.
A) MOUNT
The old CGEM mount is out, replaced by a Losmandy G11G. In the pantheon of mounts, the CGEM is somewhere around "tier three." The best "lightweight" mounts are made by Astro-Physics (Mach 1GTO) and Software Bisque (MyT). Both of these price in around six to eight thousand dollars when you add the usual bells and whistles. The G11G doesn't quite deliver the superb performance of these two "tier one" mounts, so I'll call it "tier 2," and it's about $4500 fully loaded. I went for the Gemini II version (that's the second 'G' in G-11G) even though it's not necessary for imaging--it's just nice to have in case I decide to return to visual astronomy.
The G-11G is a major upgrade from the CGEM. Let us count some of the ways:
- It's solid. Push on the GGEM head and it wiggles a little, whereas the G11G doesn't budge. There is simply no play in it
- I expect it will track far better than the CGEM. My CGEM had substantial periodic error that I could never really get rid of. The G11G will probably be an order of magnitude better
- It can connect to my laptop by way of an Ethernet cable, not a funky USB-to-RS 232-to-hand control cable.
- It's lighter than the CGEM. The head weighs over 10 pounds less and disassembles into two pieces to become even more portable. On the minus side, the field tripod is large and heavy compared to the CGEM's tripod.
- Its carrying capacity is far greater than the CGEM's. There's no telescope I own or am ever likely to own that will push the G11G to anywhere near its capacity
- There are more differences, but until I can actually begin using it (2018 crumby weather, see above) I'll not comment on them
B) FILTERS
I'm not going to say that my Baader filters are inadequate, but it's become clear that they do have internal reflection issues. And in the case of the narrowband filters their 7nm bandwidth is not as good at rejecting sky brightness as narrower filters. So out they go to be replaced by Astrodons. I plan to purchase new LRGB filters. The H-alpha filter is a needed upgrade; but over the years I've hardly used my S-II narrowband filter, so that won't be replaced. I may not even replace the O-III filter. The size filters to get will depend on part (C)...
C) CAMERA
As I write this, my thought is to continue using my SBIG ST-8300. It will be interesting to see if it still functions after a few years of rest! If I stay with it the above filters would all be the 36mm round unmounted type.
This is kind of wide open-I have the option of upgrading my ST-8300 to an STF-8300 or maybe jumping to CMOS. Cooled CMOS monochrome is an intriguing technology, but I kind of feel it isn't quite mature enough yet. If I go that way or get a different CCD it's possible I'll be able to use 31mm filters and save a little money. I have some research to do!
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I made a rare appearance at last night's monthly club meeting. I was there for two reasons-to take part in the pre-meeting meeting of the Cherry Grove Observatory committee, and to pick up some swag. I did most of the graphics designs for the ALCON 2018 national meeting and had asked for payment in the form of some items my designs appeared on. One of the club officers was kind enough to bring some to the meeting for me.
I mention this because the planned guest speaker was unable to appear at the meeting and was replaced by a video presentation about climate and climate change. I admit at first I was skeptical of what the presenter's agenda was, but it turned out to be excellent.
The speaker, Dan Britt, is a physical geologist who has studied climate change on geological time scales. While he's rather circumspect about stating his conclusions, he clearly lays out the geological evidence that illustrates how anthropogenic carbon dioxide forcing is the driving force (by far) in contemporary climate change; surface temperature is increasing and the seas are rising in his view.
This is a presentation for a non-technical audience, so don't expect to be challenged by esoteric details of the science involved. But what he says is in perfect accord with my understanding of the science.
Highly recommended:
https://www.youtube.com/watch?v=xgNxF2HlN3w
