Posts Made By: Steve Mathis

I think! A.K.A. Spined Micrathena. Strange looking little gal! Not a great photo...bad light, strong wind, swinging spider. In the woods in southeast OK.

A year ago I bought a sheet of Baader solar film to make a filter for my C11 for visual use. The size of the sheet would allow me to make a 7.5" diameter filter. I debated whether to make a centered opening, a 7.5" with a 3.5" central obstruction, or make a clear 3.5" off-axis filter. I posed the question here on AM as to which would really be the better route, and got little response. So I went for the 7.5"/3.5" CO. The results were horrible: A fuzzy image with all kinds of scattered light in the field. The much touted "black background" these filter should produce was definitely not present. I decided that this "donut" of a filter, a 2" wide strip surrounding the 3.5" CO, was worthless. So I decided to go the other route, and make a new filter mount with the 3.5" off-axis hole. I would cut the filter out of the original mount, and put it in the new one. When I started cutting the filter, this piece of clear plastic started separating from the metalized mylar. I had installed the filter without remove the clear protective cover! D'OH! Needless to say, the optical quality of said clear plastic was pretty poor, and was responsible for the crummy image. The solar image with the new setup is nice and sharp, and yes, the background is nice and black. Of course now I don't know which arrangement would have been better! Maybe when I have an extra $30 I'll start over with the experiment. I'm guessing there was something in the instructions that mentioned removing the clear plastic...

Another try at this semi-obsession of mine.

A mosaic of 18 images, each a stack of 3, 3min exposures @ ISO 1600, With an old 50 mm (f/4) Nikkor lens on a modified Nikon D50. The stacks were processed in DSS (flats and darks applied) then merged into the mosaic with PS CS3. I shot this from a mountain top that has a well-lit valley to the south, thus the bright lower portion.

I tried to calculate what offsets in RA and Dec to make between each set to keep the Milky Way centered in the mosaic, but I missed it a bit. Anyway, thanks for looking. Comments are welcome!

Steve

Here are four images from last week, all taken through an Orion 8" f/4.9 Newt OTA with a modified Nikon D50 (both purchased here on AM!). These are all full frame, and are thus at the same scale. Stacked in DSS, finished in PS CS3. Thanks for looking, comments are welcome.

I was out last night just before 9:00, waiting to try to catch a glimpse of the ISS through my 10" Dob. My ~70 yr old neighbor came over to chat and wait and watch. Another neighbor, a 20-something woman was out in her yard, so I hollered at her to tell her that the space station was going to be passing overhead in a few minutes. She said "The what???" "The International Space Station", I said, "You know, the big science lab in space". "What is it?", she replied. I explained again, trying unsuccessfully to keep the disbelief out of my voice. She had apparently never heard of it. She did think it was cool after seeing it, and said she "needed to read up on that!" I wonder how many other young people in this country have no idea (or interest) what we are doing in space these days?

I have a ST4 on the way, and plan to use it on my older (non-Gemini) G11. Are there any known problems with that combination? I don't want any of the factory-installed smoke to come out of my G11 electronics! 8)

Thanks in advance for any insight!

Steve

I recently bought a used ST-4 here, and last night tried it with my older, non-Gemini G11 mount. Everything worked as expected through the "find and focus" step. When I tried to calibrate the mount, however, nothing happened. No movement in any direction. I increased the C1 and C2 settings to their max, and still nothing. The up-down, and left-right arrows on the ST-4 did not move the scope either. The mount hand controller works fine, and, yes, I did plug the ST-4 guide cable into the HC/CCD port on the mount! I noticed that the plug that attaches to the RS-232 port on the ST-4 has only two pins in it. I don't understand how two pins (and I suppose the outer housing of the plug) can provide all the guiding info to the mount. Does that sound like the proper plug for a G11 mount? Am I missing something? Any help would be appreciated! Alex, are you out there?

Thanks,

Steve

Particularly colorful ones, at that! Probably not good to eat?

I downloaded a copy of this recently, and have had fun browsing through it. You never know when some of this might come in handy! There are a couple of entries that are a bit off, however, in the section on determining direction:

[COLOR="Blue"]MAKING IMPROVISED COMPASSES
You can construct improvised compasses using a piece of ferrous metal that can be needle shaped or a flat double-edged razor blade and a piece of nonmetallic string or long hair from which to suspend it. You can magnetize or polarize the metal by slowly stroking it in one direction on a piece of silk or carefully through your hair using deliberate strokes.

USING THE MOON
Because the moon has no light of its own, we can only see it when it reflects the sun's light. As it orbits the earth on its 28-day circuit, the shape of the reflected light varies according to its position. We say there is a new moon or no moon when it is on the opposite side of the earth from the sun. Then, as it moves away from the earth's shadow, it begins to reflect light from its right side and waxes to become a full moon before waning, or losing shape, to appear as a sliver on the left side. You can use this information to identify direction.
If the moon rises before the sun has set, the illuminated side will be the west. If the moon rises after midnight, the illuminated side will be the east. This obvious discovery provides us with a rough east-west reference during the night.
[/COLOR]

Whoever wrote this does not understand the phases of the moon, although the "right-side lit = west" works, at least if you know you are in the northern hemisphere!

Magnetizing a needle by rubbing it with a piece of silk? Are they confusing magnetism with static electricity? The manual does go on to say that you can also do this by rubbing the needle with a magnet.

When I was first getting into astronomy as a teenager, I had an uncle tell me that in the army they taught that you could tell which way the wind would blow the next day by which way the Milky Way ran through the sky at night. I didn't try to argue with him.

Check this out if you get a chance!

http://blogs.discovermagazine.com/badastronomy/2009/10/15/martian-swirly/

Amazing photo there of the result of Martian dust-devils.