Moonlit wanderings

[Davesellars]

For the last couple of days, amazingly the UK seems to be currently bathed in sun during the day and crystal clear during the night...  [i]Even [/i]more amazingly this looks to continue during the entire week (OK, I'll believe it when I've experienced it!!!)

Friday night... cold and dewy.  I was out early before 7pm with the 12" dob as twilight was still evident - mainly to try my luck on splitting Sirius.  Unfortunately, Sirius (or rather the seeing between me and it) wasn't playing nice and a fuzz-ball of fire and colour greeted me.  I think due to the cold and houses in that direction there was most likely significant thermal movement - I could almost see the vapour in the air.    Elsewhere, the seeing looked pretty darned good.  Orion generally suffered from the same thermal movement of air but in moments of calm I could easily discern E & F stars of the trapezium.

By now almost proper darkness but with the Moon already just risen and full, there was now a general lightness to the entire sky.  M42 became an interesting study into how to get the best from the nebula under less than ideal conditions.  Using my normal power with 10mm (150x), while nice lost a considerable amount of nebulosity due to the lack of sky contrast.  Also, the transparency didn't look to be that great.  Though, at 300x with the 5mm Pentax the nebula was a different beast - the contrast now good and the centre of the nebula around the trapezium showing real depth and dimension in its clouds.  I spent a good while taking this in as unfortunately it won't be too long until Orion is lost from the view until next winter.

M36, M37 and M38 were still good viewing in the ever-growing moonlight.  I stopped by the very light open cluster, NGC 1893 which with some averted vision game up considerable fine stars.

Later on, after getting the kids into bed etc and once the Moon had risen properly I went out to the dob again...  everything was now completely wet.  Fortunately I'd covered up front and drapped a cover over the scope to avoid the secondary from dewing up while I was away.  Going straight for 375x with the 4mm eyepiece the seeing was good and the image for the most part was holding still enough to make out 3 craterlets without too much effort in Plato.  I spent a good couple of hours taking in the edges of the Moon which the 12" resolved so spectacularly paricularly on the western edge around Demonax with numerous craters and mountain areas rising from the surface.

Saturday night... A bit more time to take advantage of before the Moonlight really kicked in.  Once again the dob was hauled out and cooled a while before starting around 7:45.  The conditions were very different from Friday night.  The transparency looked very good and it was dry and no trace of humidity in the air like on Friday.

I had a couple of targets in mind...  NGC 2903 (spiral galaxy in Leo) which showed up exceptionally well in the 120ST a little while back on a dark very transparent night - I wanted go back to this and make a deeper observation with the 12" dob - but seeing the sky to where Leo was the upcoming (not quite risen) Moon seemed to already making its presence in that area of the sky.  If I was guessing it probably made the sky more like bortle 6 rather than lower bortle 5 crossing into bortle 4 like I've experienced once most lights have been switched off after midnight + no Moon + great transparency...  It was quite evident when I looked upon the galaxy with the 17.3 Delos that no real meaningful observation was going to take place tonight - however a decent size elongated area with a touch added brightness to the centre appeared - going deeper with the 10mm did not improve anything or make any further detail possible.  It is quite incredible to think that a mere 4.75" scope in much better sky outdoes considerably 12".  That difference from bortle 4/5 to 6 to me is more than 3x worth the aperture.

M1 rather better placed a the time..  higher up and seemingly escaping any real lighting up of the sky at the moment, it surprised me intially with the Delos 17.3 of its sheer size appearing as an amorphous blob reminding me for some reason of an episode of Star Trek.  It had quite reasonable brightness in its entire surface area.  I attempted to pick out any strands of nebulosity within however I was unsuccessful this time.  Strangely, going to 10mm entirely made the nebula disapppear almost altogether like I was suddenly looking through it rather than at it.  Neither UHC nor OIII seemed to help with the UHC actually making things worse and the OIII giving about the same amount as without the filter.  I think maybe on a darker night this may well give up its features.

I repeated the observation of M37 in Auriga comparing from Friday night..  Considerably more contrast to the sky and better definition perhaps but it was not a stark difference to the cluster itself.  M37 such is a great open cluster to view on those Moonlit nights.

The Double cluster as ever was an awesome sight...  By now the scope had fully cooled and brilliant pinpoints of light with various colours filled the entire view.

Almost an hour was up and I had to go in to help put the (very tired) kids to bed... It had been a long day. By the time I came out again and hour and half later with the Moon well up, all the lovely stars had pretty much been lost to the brilliance of the moon-light.  However, I had come out now to observe the Moon for a little while...  This was indeed very short!  I glance with the 10mm EP for only 150x showed a shimmering mess - the seeing was absolutely terrible!  This proving to me that indeed nights of great transparency give rubbish seeing and vice-versa.  I gave up after 5 minutes and packed up to head in and call it a night.

[Paz]

Great report, that's making the most of the weather!

[Davesellars]

Just now, Paz said:

Great report, that's making the most of the weather!

You have to in this country!!!

[Kon]

Very nice report and good targets. We have been spoiled with the nice weather recently and I noticed nights are warmer to be out.