I moved
to a new spot at the state park – that dirt parking lot out front of the gate on
the road to the observatory. The trees
are kind of high, but it’s much more secluded than my previous spot, and I’m
more comfortable being back there alone.
It’s also closer to the compost toilet, which I finally found a few trips back
(which was open during the winter!).
It was in the lower 40s, but the
trees shielded me from the wind. Putting
the telescope together by myself took a lot longer than I had anticipated, so I
didn’t start getting images until almost 10 PM.
I came up with a clever idea to keep the battery from getting cold – I
wrapped the 8-inch dew heater around it, and covered it in a fleece blanket,
and turned up the heat. The alignment
process worked well and worked the first time, for once. Its initial guesses at the two alignment
stars and the first calibration star were terrible, but it cleaned up pretty
well by the third calibration star. I
used Sirius for the all-star polar alignment.
I started with one more go at the
Orion Nebula, although it’s in the western sky now, toward the city, where
there’s lots of skyglow from the city lights.
There were also some high clouds I could only see in long-exposure
images. So my Orion photos came out
terrible. After about 35 of those, I
slewed to the Cigar Galaxy, M82. It
wasn’t showing up in my photos though, even after fishing around for a bit, so
on a hunch I tested whether it was still aligned – I had it slew to Polaris. It was most definitely not. So, without power-cycling, I re-added the
alignment and calibration stars, and it stuck.
I found M82 with no problem. So I
started that set going, and went and read in the car. I forgot to check what time it crossed the
meridian – I only got about 20 images before it did, and another 20 had massive
star trails since the scope had stopped moving.
So I had it slew to M82 again – and again, it was way super off. So I power-cycled and re-aligned (I didn’t
have to re-polar-align, since I hadn’t moved it), but it wasn’t working; it was
way off on goto. By this point, it was
about 11:45 PM, close to quitting time.
So I gave up and packed up.
The
battery was nice and warm, so I think we can rule out the battery being cold as
a cause for it getting lost. It sounded
again rather terrible when it was slewing, more in declination than right
ascension, though. This is in part
caused by the fact that I balance the telescope with the camera attached, and I
align using the star diagonal and 25mm eyepiece, so it’s not balanced when I’m
doing that, but it sounded worse than it did earlier in the evening when I was
aligning the first time. It really
sounds like it’s not getting enough juice, but I don’t think that that’s the
problem, unless the battery is crapping out on me. My next suspicion is that the grease in the
gears gets too viscous when it’s cold, so it’s working against that as
well. So I’ll have to wait until a
warmer night to go again, I think.
On the bright side, the 20-or-so pictures I got of M82 yielded 18 decent ones (I’m pretty liberal with how much star asymmetry I allow at this point, since I haven’t yet had a good night with a lot of pictures to choose from). Even with only 18x30 sec images, it came out pretty well!
M82 Cigar Galaxy, Nikon D3100 on C11, f/6.3 focal reducer
18x30s, ISO-3200, no flat [I just made the background really dark in post-processing to hid the vignetting]
