Sometimes, you’ve just got to do it.
This weekend has been the start of a 5 day break of work
for me. So, with bits and bobs planned,
I’ve had the luxury of not really needing to be up and about at any particular
time. Except that is for the Great
British Beer Festival in London Olympia.
But that’s another story. Coming
back from London on the train, I had a quick look at the weather forecast, and
it showed the potential for some scope action overnight. Slightly jaded, and somewhat tired from the
trip to GBBF and a day at the Science Museum, it was going to be touch and go
if I could stay awake long enough.
Coffee was the answer!
Skies were clearer earlier that forecast, so I set the
SBT up around 9.30 ish, checked the collimation and had a quick scan
about. It was still too light to start
any sort of observing, so I left the kit out and returned inside, but by 10pm I
was back outside and ready to go. First
of all, a quick trip around some targets that I have seen before. Doing this, I find it gives me an indication
of how good the conditions are for observing.
I’m able to compare familiar targets to how they appeared on previous occasions. Conditions were good, though not excellent to
start. There was still a high thin layer of cloud just taking the edge of
things, but as the evening progressed and the temperature dropped, conditions
improved.
The first targets for the evening were the Ring Nebula,
the Dumbbell Nebula and the open cluster M52.
When observing the Dumbbell Nebula, I thought it was a good opportunity to
try out one of my filters. I haven’t
used any of my filters with the SBT so thought, again while on a familiar
target, that I could try it out. Without
the aid of a filter, I felt the best view was given by my 25mm eyepiece. The nebula was distinct, with the rough
circular appearance characteristic of it.
However, no sign of the shape which gives it its name that it is often
present in photographs. I chose the OIII
filter and attached it to the same 25mm eyepiece. The difference was certainly notable. Though in practice, any filter reduces the
amount of light entering the eyepiece, different filters will block light of
different wavelength. So, the overall
effect of this particular filter on this target was that the background sky was
darkened significantly, without having the same dimming effect on the rest of
the nebula. With the filter in place, I
was able to see the start of the more traditional shape, now that the
nebulosity was sticking out better against a darker background. This was just the start of my play with
filters for the evening.
In my last post, I referred to the list of the Messier
catalogue object which I made in my notebook that I have left to observe. I again referred back to this list for my
next two targets. The first of these
targets, and the first new tick for the evening was M94, a spiral galaxy in
Canes Venatici. Whether it was the
seeing conditions still hadn’t settled down, or this object is genuinely tricky
to see I don’t know, but I found the target easy to locate, but hard to
define. It’s magnitude of 9 is well
within the capability of the SBT, but I found it hard to not any structure on
it at all. I observed the galaxy at 32mm
and 25 mm and could make out the bright core with ease, but little else.
Undeterred, I moved on to the second new target, M106. This is also a spiral galaxy in the same
constellation as M94. Again, this was
tricky to locate, showing its bright core with ease. However, it didn’t appear as bright as M94,
but oddly, M106 did seem to show slightly more stretched structure. To try and get as much light from these
objects into the eyepiece as possible, I only observed at 32mm.
During my last session, I was really pleased with my
first observations with the Veil Nebula, but noted that I could only see the
Eastern Veil. Tonight though was to be
significantly different. In an ever darkening
sky, I brought the SBT around to the constellation of Cygnus, and the location
of the nebulae that make up the Cygnus Loop.
I easily located the star 52 Cygni again, which I did observe
previously, but reported that I failed to make out any nebulosity. However, this time, I thought I could make
out a slight colour variant stretching through the star and out each side. NGC
6960 goes by a number of names and designations. Notably, the Bridal Veil Nebula, Caldwell 34,
the Western Veil Nebula, and the Witches Broom Nebula. It was time to break out the filters
again. I did a direct comparison at 25mm
with firstly, the OIII filter. I then
switched to the UHC (Ultra High Contrast) filter. Out of the 2 filters, this time, I think the
UHC filter performed the better. These
are the notes I made in my book from the night.
“Fantastic
nebula. Filters do an amazing job, but
UHC better out of the 2 I think. Wide
and well defined, narrowing to star 52 Cygni, then wonderfully thin and
extended.”
The nebular, with the aid of the filters, stepped out of
the darkness brilliantly. Both filters
in their own ways brought the grey wispy nebulosity into sharp definition from
the darkened background of the rest of the night sky.
I felt I was on a bit of a role, and decided to look out
some other objects not on the Messier catalogue, but that I had heard of
previously. So, next, I chose to look
for NGC 4490, the Cocoon galaxy. I
seemed to take a long time to try to locate the galaxy, though looking
seemingly in the right place. According
to the charts and my Telrad rings, I could locate Cor Caroli, following it
along until I come to the galaxy. I
found the galaxy though quite dim, but couldn’t for sure say that this was
correct. The star atlas say that I
should also see NGC 4485, a magnitude 12.5 galaxy in the same vicinity. I think I could make something out the prime
target, but more of the appearance of a lightly smudged star. The two galaxies apparently look like there
are interacting in some way. However,
because of the low elevation of the target in the sky, I expect that conditions
were hampering the quality of the observation.
Nevertheless, I had seen enough to convince myself that I was looking at
the correct galaxy, especially when re-referencing back to my Telard chart and
sky atlas.
Time was now pressing on, the bells in Ross had rung for
midnight some time ago. The temperature
had dropped significantly, and there was a heavy dew on the lawn. I’m pleased to say that this didn’t seem to
effect the performance of the telescope through the evening, but did give an
indication of how much moisture there was in the atmosphere.
I decided to call it an evening around 1am and retire to
bed. Though I hadn’t observed lots of
targets, the ones I did were important.
Put together with the experience of using the filters with the SBT for
the first time, I feel I now have a bit more idea of the circumstances I can
use them. All in all, an excellent night
with some good quality observations.
Cheers!
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