Getting focused

Here's something interesting... just read about a "Bahtinov mask"

It is placed in front of the primary mirror (not sure if that has to be right in front of, or up at the aperture is OK) and the offset grids create diffraction spikes in the image of a bright object than you can then line up to ensure perfect focus.

I wonder if I can make one? Hmm...

Eta Carina

Tonight is a full moon, or nearly, and finally a clear night after a few warm evenings that were still clouded over.  I was curious how clear the Carina Nebula would be when the moon was so bright, and it would also be good practice to try to locate it again in more difficult circumstances.

It did take a while to find again, even though I had a fairly good idea of where to start.  I initially tried to start with the star at the bottom (or right when it is rotated) of the False Cross asterism that makes the end of Carina and then move down from there.  I did get a small distraction from NGC xxxx which is a nice open cluster, and then I moved down from there but I started to feel lost, as it proved to be a long way down.  I then tried jumping to where I thought I remembered it being but ended up in a relatively featureless bit of sky - or so I thought until I stumbled across what I think was the centre of a tight globular cluster that showed as a very interesting small blurry patch.  I'll have to look that up on Stellarium.  Unfortunately, I knocked the scope when changing an eye piece and lost track of the object before I could even try to memorise where on the sky I was looking.

I then noticed that my averted vision was picking up some faint spots halfway between Crux and the False Cross that looked intruiging, so I swung the scope around to the best of those and immediately landed on NGC xxxx, which is another open cluster.  Recognising that from last time, I was then able to track the scope a bit higher, and finally landed on the Carina Nebula with Eta Carina shining bright orange in the middle of it.  The nebula was almost impossible to see, and without the memory of last evening observing it I would have had a hard time identifying it.  The nebulosity was very faint, and I could only just make out the structure of the lobes and the dust lanes across the middle of it.

I spent most of my time here switching between my 30mm looking at the big picture, and then zooming in with my 13mm and 6mm and then added the Barlow for 2x magnification.  I think the best results this evening were with the 13mm plus the Barlow, which allowed very nice viewing of the faint nebula and Eta Carina in the middle, with the lobes of its nova event just discernable.  I also spent a lot of time just staring at the sky and double checking through the finder-scope the location of th the nebula, so I will be able to find it much easier next time.  

The evening closed after midnight with some faint whispy clouds moving in from the South West, so it was time to pack it in.

Getting familiar with Carina

This year, as part of my constellation upgrade process I'm planning to pay more attention to a single constellation each time I go out to observe.  That way I can get familiar with it before I then move on.

I started last night with Carina, which is a pretty big constellation, so I think it will take a couple of evenings to cover fully

Starting at Canopus, I then hopped up to Avoir and underneath that found the open cluster NGC2516. From there I hopped across to Aspidiske and worked my way down the open clusters NGC3144, NGC3293, NGC3532, and NGC3766 that wrap around the asterism 'the false cross' and down to the real cross Crux. (and a quick diversion into splitting the binary stars in Acrux)

The find of the night was stumbling across a nebula with a orange star in it. I'm sure I should know it, so I'm going to research and put my findings here...

(some research later...)
OK - wow.  I guess this is the result of mostly observing in city skies and usually with some moon interfering as well, but last night the quarter moon had already set - leaving the sky dark enough to make finding NGC 3372 easy.  Otherwise known as the Carina Nebula, the Grand Nebula or maybe the Eta Carina Nebula!  Returning to this object is going to be a regular challenge now as I continue to add hits to my NebulosCity roster.  It is a beautiful structure, showing three lobes, divided by a distinct dust lane down the middle.  I'm looking forward to looking at it more closely under better conditions and seeing even more details.
Its interesting that I haven't identified this nebula before especially since I went looking for Eta Carina some time ago, and found it.  The night must have been too bright to make out the nebula around it.  I've got this one dialed in now, so I'll be returning to it as frequently as I return to Orion.

Then I finished up the evening looking for a planetary nebula above Carina - but I was getting tired and packed it in before succeeding, those can be for another evening.