Brief OR: Driveway test (more of an ATM report?)

[Akarsh Simha]

Lots of changes to my telescope. My new round ground board that I cut on the CNC router at our local makerspace needed to be tested out. I’d also messed around with the positions of the altitude roller bearings to attempt to better make them true. 

With the teflon pads (thank you Mark W.) placed a bit further out than the previous ground board, the friction is expected to increase, but I also placed a central teflon pad to help some.  Kriege explains in his book that if one is using a central teflon pad, the ground board has to be extra thick to ensure it doesn’t simply bend away under the weight — well, mine isn’t. So I didn’t know if the friction would turn out to be usable at reasonable power for deep-sky hunting and tracking.

After fifteen years doing apartment astronomy in this country, I’m finally renting a place with a driveway, so I set the scope up in the driveway for the first time. The altitude felt fine, but the azimuth was a bit stiffer than before if I recall correctly. However I was able to comfortably maneuver it.

You can’t observe much from the city, especially from a heavily obstructed driveway. I started on Jupiter which reminded me I hadn’t collimated the scope and looked mush. Anyway I got first confirmation that the movement at high power is smooth enough! Going up to Pleiades, I naïvely attempted Barnard’s Merope Nebula — its high surface brightness right? Nope, negative. I couldn’t even see the reference stars.

I was still hanging outside in the cold for my housemates to come by as they hadn’t seen through the telescope. My neighbor came by and I showed her Jupiter and Orion Nebula. Incidentally, I see the reddish and greenish hues in Orion Nebula much better in the city - this is the second time. I think the light pollution has the same impact of suppressing the overwhelming signal from the cones as the “flashlight method” does, except it’s clearly safer.

I was still waiting for my housemates to return so they could look through the scope. In the meantime I asked ChatGPT to search the internet and find me the all the NGC/IC-listed planetary nebulae in Auriga and Perseus. Amongst the ones it found, I had seen all except NGC 2242, so I gave it a shot. City observing is frustrating but not impossible; so many stray reflections everywhere. I got the right field and thought I saw it, but it did not respond to a nebula filter. Then I looked at its magnitude — mag 15. Again, so naïve of me. Nope.

With nothing else visible in the sky I took a brief look at Mesarthim, one of my favorite double stars. Then headed over to Mirach to see if I could pick out NGC 404 without knowing exactly where to look. What a surprise, it was there pretty easily visible despite the light pollution.

My housemates arrived and I showed them Mesarthim, Almach and the Double Cluster — everything else of interest was obstructed. Double cluster actually looked pretty swell for being in a Bay Area driveway. Then I tore down the telescope.

Of course the next question was given the larger ground board, if it would fit into my truck smoothly. No troubles loading it.

All in all a success. As a bonus, I found out it took about 60 Nm of torque to break my azimuth stiction and about 40 Nm to break the altitude.

Looks like I’m ready for the weekend. The forecast for Saturday is marginally better now, and Friday is better than Sunday but I may still pick Sunday.

Clear Skies

Akarsh