Friday, June 19, 2020

imaged Vulpecula doubles (Bradford)

Quick report: will be replaced with detailed log entry later...

Wow. Just wow. Weather reports were lookin' a little sketchy but a trip out in the early evening was surprising, with clear skies, despite the cloud blob blowing up from New York state and over the lake. And when I headed out with all the gear at 11:30, it was still looking rather good.

No major telescope problems. I did have a collision in RA but that was because I had wound the clutch lever too far. Happily, a restart corrected it. And at some stage, I hit a button with a menu open and the mount started slewing fast and I saw a screen that said to power off. Amazingly, I was able to recover without having to redo the alignment. The pointing was still off and I had to sync but during the imaging run, I don't think it was an issue.

The main goal was to do some image gathering for double star measurements. I had seen a ton of doubles in Vulpecula and my checks into the Washington Double Star database did not yield and hits. So I think I've found a dozen uncatalogue objects. This will be fun reducing all the data.

It will be perfect if I can image the same area tomorrow.

I noted clouds as I exited the backyard. Good timing.

How many nights has this been now? What an amazing run.


Fancied doing some "work."

11:43 PM, Thursday 18 June 2020. Camera gear back out. Found kickstand for voice recorder. Tent was open.
Instrument: Celestron 8-inch SCT
Mount: Vixen Super Polaris
Method: slewing and tracking with IDEA GoToStar
Powered the mount. Checked the date and time in the GoToStar hand controller—fine. Performed two-star alignment. Prompted for Albireo again. The first star was in the finder FOV. [ed: Or did I do the wake-from-park-resumption trick?]

11:48 PM. Off to the second alignment star: Arcturus.

Something weird happened. The mount rebooted... I hoped that wasn't a sign... Did I bonk a power cord? Oops. A collision. It was the RA lever hitting the motor cover. I had tightened the lever so much it interferred with the box over the motor. Retightened but not too much; checked clearance. Here we go again. Restarted. Now Albireo was not in the finder. To star two. Mount seemed OK.

Frickin' mosquitoes harangued me.

Report: 1" lower and 22" east. Wow.

Almost midnight. Connected computer. Readied to slew to a star... Miss-hit a key on the paddle. Some message out of the corner of my eye about powering down. Oh no. What happened?! Trouble! Fartknocker! Hit Back again... Was it OK? Wanted Vega; selected the Double Double.

12:04 AM, Friday 19 June 2020. Spotted a wispy cloud. First I had seen in days.

The slew completed. All seemed OK. Wanted Vega, still, for focusing.

Hooked up all the gear equipment and software. Closed unnecessary apps on the old netbook. 

Spotted more wispy clouds to the south-west.

Didn't have my phone so loaded the Good To Stargaze page for the local weather. Switched to my WLAN.

Started Frame and Focus. Panned slowly with the hand controller to centre the star, or rather, that diffraction pattern. Fine-tuned with the loaner Bahtinov mask. Good.

12:23. Test shot with Vega. 5 seconds, ISO 1600.

More clouds.

Air temp: 19; humidity: 67. Applied those numbers to the wx text file for BYE.

12:28. Shot Vega again.

Oooh. Forgot about the 2x. Oh. Thought about it for a minute. Decided to leave it out. Berko had told me I had to get the focal length over 3 metres. Sorry. Going with 2 metres.

Slewed into Vulpecula.

Took two test shots, 5 seconds each. Caught STF 2515 and WSI 22.

Rhonda popped out for a bit. Showed her the current image: lots of doubles. Shared my discovery about the Atmosphere store. Pussy willow hunters completely deflated her. Sorry to hear that. Talked about the feral cat. And the crazy change in temperature.

Altair looked to be the closest bright star.

12:40. Started drift test shots... 60 seconds. Off by more than 45 degrees. Turned the camera. 90 seconds. Still 10° off. Oh. Nearly perfect, alignment; but not long enough. Turned back a hair. 120 seconds. 

Slewed to object. Noticed the GoToStar system went back into sidereal mode upon a target slew.

Applied filename "drift." Set to 150 seconds. Camera temperature was 25, 7 above ambient. Dew point was 12.

Considered my routine at the CAO where I programmed the times and just operate the mount inside that framework.

Slewed by to target. A little to the left. Tracking off. 180 seconds. Yes, single lines all the way across. Camera sensor still 25°C. 

I made a short list to only show "reobserved" objects.

The sky looked clear, no clouds anywhere.

Tried to figure out my directions. Hurt by brain in the process. Added HD 183459 to the observing list. Slewed. Filtered the list again. Watched the atlas while the drive was off. Tried to sort the math of it...

1:08. Readied to shoot my series of 10 drift shots. Set a 15 second gap.

Slew. *
Watch for "slew complete" message.
Wait about 5 seconds. *
Turn drive off. *
Shutter close. 

* Steps required a human.

The 15 second gap was good. Didn't have to rush. The drift was the most time-consuming part of this...

Humidity climbed 2 points to 70%.

With the drift images, I knew north was up.

1:20. Watched the hand controller display. Corroborated with SkyTools. Altitude 60°. Good. Airmass 1.2. Really good news.

18°, 70%, dew 12, so about 5 degrees away.

Slewed. Air mass just went down to 1.1. Sweet. I was not seeing any clouds. Bored. I wondered if Sequence Generator Pro could do all this. I spotted Jupiter and Saturn. 

Wanted my comfy chair. Between shots, switched chairs. Oh, much better.

15 minutes to go. Camera was hotter at 29 degrees. No clouds.

I remembered the third star, the 1-2-3 stars, with Altair: Alshain. So Altair, Tarazed, and Alshain. Yes.

If my calculation was right, the target area would reach the meridian at 3, I would have and hour and 15 to image doubles in Vulpecula.

Spotted clouds in the south. No wind. Humidity went to 71. Heard an animal.

Camera temp still 29. 

drifting stars to alignment camera

Worked last shot. Considered returning to the "starting point" and doing a long exposure. Done. Yeh!

Coil still going.

1:45. Camera temp 30. Changed to a single shot from 10. Altered the filename to "vul200618a." Took a long exposure, 25 seconds, ISO 1600. Nice. Interesting doubles... Exciting. Saw slight trailing. Changed to 20 at 3200. Changed the delay between from 5. Motion, ugh. Tried again. Pretty good. These shots include Tycho 1612-753-1.

Started some field identification. Thought about how I needed to proceed. 

1:55. Slewed then shot.

Slewed, panned. Slewed, panned.

2:00. Shot. Included HD 183013.

Programmed 3 shots of each area. Started a routine inspired by a spiral search function, in TheSky software. 

2:06. Found cables getting tangled.

Let go of the hand controller, didn't really need it. And I would avoid snags. Simply commanding slews from the software. Tried to do a bit of overlap. Camera temp was coming down: 25.

Enjoyed all the little doubles.

2:15. Looked for my toque. Or a cap.

Noted a big drift in the image. I wondered what happened. Good on second shot. Weird. Glad I was shooting more than one frame.

More drifting. I realised it was the gears, the slop in the motor system: backlash. I was moving west to east... Continued working across the top row.

2:24. I knew that with these images, I would be able to measure position angle and separation but I wondered how to estimate magnitude. Wait. Do I have to? I'll have to review papers submitted for new discoveries...

More drift, in all three images. Long settle time! Redid the three. 

Computer was still on battery power. Between shots, plugged in the supply to avoid a disaster.

Slewed. Waited a few seconds. Saw it was still drifting. And I noticed the motor note. When really loud, it was free-wheeling. Shot them again. Maybe I have to wait 1 minute...

Slewed. Waited for about a minute. Took the opportunity to close the east door. Heard the motor note change. It worked. Wait... Not long enough. The backslash delay was maybe up to 90 seconds!

2:44. Thank you very much.

Graceful shutdown.

2:45. Checked the Oregon: 51%, 18.6°, steady pressure, rain.

2:49. Parked the 'scope. Again, it landed at 88 degrees and change. Vertical position looked perfect.

Closed the tent. Lights off. Packed up gear, although I left the body in place, so to facilitate a repeat run. Good timing—clouds rolled in. And the mozzie coil just finished. Put the computer into hibernate mode. Spot checked. 

2:56. Exited.

Pretty good session, despite glitches at the beginning. I felt I had captured some good images.


Images uploaded (and briefly analysed) on 22 Jun '20.

Detailed analysis of first image completed on 24 Jun '20...

No comments: