Tuesday, March 08, 2011

no data on Ludmilla (Pontypool)

Good data was not collected on the Ludmilla occultation. I actually don't think I was on the correct star. But the video quality was so poor, it would have been difficult or impossible to conclusively report the occultation.


Uve picked me up from my home at a little after 7:00 PM. He reported, during his drive from Scarborough, that he could see some clouds in the west. This discouraged the both of us. But he said he would follow my lead. I didn't wanna go if we were going to get clouded out! We hatched a plan to pop in to the RASC City Observing Session at Bayview Village Park to assess the skies. If it looked bad, we could do stay put, some quick observing and save the time and gas.

I scanned the western horizon as we drove up the DVP. I could see Jupiter just above the city skyline. That was a good sign.

From the park, while hanging with Stu, Bill, David, Ed, and crew, we noted the skies looked very good. Decent transparency. This improved our mood.

Uve asked if I thought his binoculars were OK despite a scratch on one objective. I thought the views satisfactory.

We enjoyed views on the Moon, the Orion Nebula, and the Trapezium (along with the E star) in Stu's 85mm refractor and Bill's 9.25" SCT. Seeing the shuttle and ISS flyover (at 8:32) gave us a big shot in the arm.

We departed BVP for Long Sault, happy to warm up in the car (forgot to note the temperatures during the evening but I seem to recall Environment Canada predicting a low of -7°C). Grabbed some coffee at Tim's in Bowmanville and continued north. We found Steve set up and waiting in the parking lot. He had started to worry we weren't going to show. He had sent me an email at 9:35.

After we assessed the views and sight lines, the guys helped me complete the regular setup of the Celestron 8" SCT right at the east edge of the parking lot. Connected the dew heating equipment and motor drive to the custom dual CLA power outlet on one deep discharge battery (leaving the other isolated battery for the occulation rig). I bolted up Williams Optics mirror and 2" baader eyepiece to do some quick observing. It also gave me a chance to demonstrate to Uve how the Bahtinov focusing mask worked.

Then I setup the occultation gear including Vixen flip mirror. Before it ducked behind the trees, I used M42 to show how one could draw out details of nebula using the integration settings. It looked like I was pretty well ready to go. We headed to one of the cars to warm up. The north wind was bracing. It was around 11:00 PM.

At about 11:30 PM I returned to the 'scope to finalise the occultation recording gear setup and find the target star.

The power cable from the StellaCam3 slid out at one point as I was moving around the telescope and getting cables settled. I was not surprised when the cord decoupled. The A/V-power cable is not well designed. The way the cable feeds into the camera puts tension on the power cable. It really needs to be looped around something or secured to eliminate the chance of this happening. I reconnected the power cable, noting the typical blue-white spark.

Looked at the monitor display. Nothing... It was then I noticed that only two of the three CLA plugs were showing their red LEDs. Fuse! I blew the fuse. When I reconnected the camera power it overloaded the circuit. I knew I had not seen an extra fuses in Denis's kit. But before I could panic, I remembered that I had all my dew heating gear here including 12 volt hair dryer and the 12 volt coffee cup warmer (as impromptu finder scope warmer). In fact, the cup warmer cable was close at hand as I did not have a plug for it to attach to.

I slowly unscrewed the end of the plug, warning the guys that they were often spring-loaded, recounting tales at Mew Lake. I carefully removed the glass fuse. When I heard something small fall to the ground and bounce off Uve's boot! Oops. It took us a couple of minutes to locate the centre metal button for the CLA plug. Sheesh.

I put the good fuse in the camera power cable and I was back in business, red LED aglow, camera fan cooling.

It was around this time that Lewis arrived with coffee, tea, and Timbits! I energised two of the sodium handwarmers. Uve was very impressed. Put on my custom deep red flashlight with headband.

I had SkyTools3 configured and activated its telescope view. I reached the view as shown in the finder scope but then struggled with the eyepiece view. Asked Steve to check. But, in the end, I was not convinced I was at the correct location. The eyepiece orientation was throwing me off too. I was not sure which way to rotate the field of view. But with time winding down and I had to move on.

I activated the flip mirror and checked the view on the Oslon monitor. And couldn't see anything. I knew the focus was off. We spent a couple of minutes searching. "No wait," Steve said. "I see a star!" Indeed there was one star on the monitor. But only one. It was barely detectable, flickering and shimmering in its low altitude.

I double-checked all the camera settings on the control pad. Tried the gamma at all three settings: off, low, high. Cranked the gain to maximum. Stars appeared with the low integration settings but I reminded the guys that this couldn't be used. It looked like there was something wrong with the camera or the telescope. I checked the corrector plate. No dew. It didn't make sense. I had see dozens of stars in the finder and many stars in the 26mm eyepiece.

It just didn't make sense. Was it the elevation of the star (now around 20°) and the related atmospheric extinction? Was there cloud there, that we couldn't see, but the camera was detecting? Was it stray light from Toronto given that I was aiming west? Was it light pollution and cloud together? The focal reducer was installed so my Celestron 8" SCT was not acting like a f/10 but rather an f/5. My expletives were recording on the audio portion...

I didn't see much point but I connected the camcorder and recorded the field for a few minutes. Recorded the mystery star from 12:10 to 12:15. No change.

Frustrating. So close and yet... Steve kept laughing, "All that... All that!" Lewis asked me if I wanted my ice coffee.

Removed the camera and inspected the glass of the focal reducer and camera. All clear. No dew.

Wound down showing Lewis some double stars. He had a hard time splitting Castor at 77x (or was it 55?); it was easy at 222x. As I was doing this, I noticed the finder scope was not in-line. Oh oh. It proved to be out by about 1/4 or 1/3 of the field. And that would equate to more than 1 degree. Which might explain why the FOV in the eyepiece didn't seem right...

1:26 AM. Sent Guy a text message to ask how he did. I probably woke him up...


Lessons learned:
  • Have at least 1 spare fuse for each device.
  • Realign the finder scope after any rotation.
  • Avoid distractions.
  • Give yourself (even) more time to prepare.
  • Don't phone or text other team members during or after. They may have been clouded out, gone home early, and may be sleeping.
Things I forgot to do:
  • Take location weather reading with pocket sensor.
  • Record longer than you think necessary, i.e. 5 minutes before and after.
  • Tune the eyepiece so to be parfocal with camera.
  • Reset Kiwi at end of recording to verify time synch and to capture date and elevation.
  • Netbook red film and keyboard light.
  • Astronomy box α with red film (for Oslon monitor), lanyards, towel.

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