Friday, August 10, 2018

went moon hunting (Blue Mountains)

Fired up my netbook computer. Set up on one of the west tables in the Geoff Brown Observatory. Installed the red film (temporarily).
Instrument: GSO 16-inch RC
Mount: Paramount ME
Method: Go To
We viewed Mars. The south ice cap was very obvious. Some dark regions were visible. I wondered what features were facing us. Good to see again.

I saw a point of light about 5 or 6 planet diameters away. This seemed to match the view presented by my SkyTools 3 Professional software.

10:41 PM. Started concerted Mars moon hunting...

We used my occulting eyepiece in the GSO 16-inch RC telescope.

Steve thought he saw an even tighter object. Very close. In the diffraction ray.

That seemed too easy, to me.

Deimos was 11.6; Phobos was magnitude 10.5 and very tight to the planet. Mars was -2.6! Bright.

Chris didn't see it. Steve said there were 4 rays. Yeah. Vertical ray. Second ray down. Just below the second ray. Very close to the middle. Steve said there was a faint point 3/4 of the field (from centre). Oh. That's a star.

I couldn't get ST3P to show the field stars in the area. Ensured the time was correct (or current).

Steve saw a good Perseid, along the Milky Way, which left a smoke trail.

Anne was curious about the eyepiece. I explained how it came to be. Occulting eyepieces are useful for bright planets or tight double stars.

It seemed like the field was wrong in the software.

The polar cap was at the 1:00 or 1:30 o'clock position for us.

False alarm. Sorry. My ST3P settings were not right. When I put south pole of the planet at 1:00, the stars weren't right.

Checked the telescope settings. Compared to other reflectors. Inconsistent. Turned off the planet icon in the chart. Asked Chris for the eyepiece focal length.

We discussed telescope types. I argued it was a reflector. After some changes to the presentation settings, I thought I had the field right. Reset the time again.

Chris saw a triangle of stars.

10:50. I was curious the weather conditions. I amped up the humidity setting in ST3P to dim the field.

Schlanger. The view still didn't seem right. It hit me. The RC 'scope had three reflections. Ooh. The kid was right! Using the stock setting for a reflector was not right; the GSO would present a view like an SCT! I reconfigured SkyTools. [ed: The Richey-Chretien is most like a Cassegrain.]

Chris was working on an asterism. I compared the field to his chart view from SkySafari. No... no... the brightnesses were not right.

I suggested to Chris that we move to a known-good to verify the field orientation and presentation. He proposed Saturn. That would work. We programmed TheSky 6 and the Paramount slewed. Oh. It flipped over the meridian. Oh well.

Titan was at 2 o'clock. Two moons at 9 o'clock, faint and close. Rhea and Dione were way off at 8 o'clock. Chris spotted a nearby asterism. I got my software sorted finally. Chris confirmed with his app. Mimas was mag 13.2. Iapetus was 11.4. We talked about flipping options in software. OK!

We headed back to Mars.

I saw the ice cap was at 1:30. A bright field star...

11:20. Chris thought he got it. Showed Steve. One ray, a strong one, went straight out to the right. He saw a point touching the top edge of the ray, about 25% of the way out. They thought it was Deimos. Phobos was now behind the planet... Steve saw it for a second. They worked some other field stars. Chris didn't think the stars were good in SS. And it only went to mag 13.

As I returned from the house I noted all the planets: Venus, Jupiter, Saturn, and Mars. Out of the corner of my eye, I kept thinking that Mars was an Iridium flare.

I confirmed a pair of stars. The field of view looked right, at last. Continued checking.

11:29. Sat down. Moved the computer nearby. So to do a deep star field comparison. I had to put the chair very close to the pier. It's a bit trickier now with the GSO as it is more forward in the cradle... Deimos should have been at the 4 o'clock position.

Denis popped in for a bit. He was imaging and happy that everything was working for him.

Saw a mag 12 star. I kept concentrating on the field. No... Not seeing it. The diffraction spikes were not in the ideal location... There were 8 diffraction spikes from Mars...


Midnight. Done chasing...

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