Blog Sunday Feb 5th 2017

 

A clear sky drags me from my warm bed and out to the observatory carrying the obligatory cup of tea. I’m moved by the sky that greets me once outside of the back door; despite the fact I’m not dark adapted the sky is still spectacular. I’m momentary disorientated by an unfamiliar sky as this is a late spring evening sky, not the mid winter one I have become accustomed to! I work from Arcturus locating the constellations until I’m familiar with the scene which takes a few minutes. Jupiter blazing to the south makes the sky look rather odd too.

 

As I enter the observatory I decide that I shall hunt down an Arp galaxy in Bootes for a sketch. Five minutes or so sees the scope slewing to Arcturus and it is soon centred on the monitor. I decide on Arp 43 a short hope from the brilliant yellow star. The goto puts the fuzz of a galaxy just on the edge of the fov with the camera set to a short exposure; I centre the ‘fuzz’ and extend the exposure to 10 then 15 seconds. As the camera settles I given a busy but rather grainy site, clearly a very nice spiral plays the central role with a smaller fuzzy galaxy just off the end of one arm, there are clearly many other faint and tiny galaxies in the field, one revealing itself as an edge on. I fiddle with the monitor and camera settings before deciding ‘this is the best view I will get’ and freezing the frame. It is now 5am and dawn will not be far off, with the frame frozen I can sketch at my leisure with now fear of losing my target. I get the stars draw in Ink and add the galaxies, the very faint stars I add last with gentle dabs of a pencil. Happy I have captured the view I take off the freeze function and the image is refreshed, the image shifts by around 25% but is pretty similar to that I froze 30mins before, then as often happens with Watec video cameras for some unexplained reason on a 15 sec frame refresh the screen goes very bright, normally I ignore this and things settle down on the next refresh. However on this occasion despite the very bright back ground the image of the main galaxy, was far sharper and more defined that before although the fainter outer regions were washed out! Quickly I froze this image and turned the image brightness down on the monitor; to my delight the resulting image was far cleaner and more defined that the previous one, in fact I would go as far as saying that it was way better than the Watec commonly delivers! What is going on I wondered? Not to look a gift horse in the mouth, I got to rework my sketch; I could now see a fork in one arm of NGC 5829 which is the main spiral and the other arm that points towards a close by bright star showed a string of tiny bright knots looking rather like a spine. The cluster of fainer galaxies now showed their true nature, bright cores and diffuse outer halos no longer just non stellar smudges! I would love to know what had happed to the Watec to deliver such an awesome image? After all if it can deliver such as a “glitch” why could it not deliver the same by design?

A 42 with Hickson 73 companions

 

OK enough on that matter, I noted on the Carte du Ciel display that close by was another galaxy, not sure what would show up at 6am, I sent the scope there and was delighted to see a pair of fairly bright galaxies close together. I twiddled the knobs, froze the frame and sketched NGC 5859 & NGC 5857, the former showing quite considerable spiral detail and being the larger of the two. NGC 5857 however had a noticeably brighter core, a very nice pair of, as I found later, non interacting galaxies.

NGC 5859 & NGC 5857

 

With my observations in the bag, I did some research on Arp 42, finding out that the largest of the galaxies after mag 13.9 NGC 5829 was in fact IC 4526 with a mag of 17. I also found that Arp 43 which is made up of these 2 galaxies also forms part of Hickson 73 along with a number of the fainter surrounding galaxies! I had therefore observed and sketched this group a number of years ago as H73! I compared sketches and this is by far the better of the 2, especially when viewed as originally drawn black on white!

 

 

 

Dale