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Cirrus or a Galaxy?


BiggarDigger

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I managed a short session last night (31st August) which reminded me to always keep one eye on the bigger picture.

Out at 9:30pm under veiled skies still brightened by the setting sun.  Still, it allowed the 200p to cool down a bit and my vision to adapt.  It was cold enough to need thermals and my winter coat (we are abut 225m above sea level and the nights here can be quite chilly even in late summer).

Seeing wasn't good with lots of cirrus floating around, but Clear Outside suggested an hour or two of decent seeing so I persevered.  Mars was very bright but shimmering too much at low elevation for a good view.  Jupiter was just setting.  We have good clear views of the horizon from the East all the way round through South to the NorthWest, with one exception: a 10m Sycamore tree just into the farmers field beyond our boundary about 10 degrees west of South.  Unfortunately Sagittarius falls into this "hole in the sky" at this time of year, so I decided not to even try and swung the dob round to the North East to find M31 and its companions.  Visible to the naked eye, I was hopeful of catching a few other much fainter galaxies in Andromeda in the eyepiece, but alas the cirrus was blotting out too much to see anymore than M31, M32 and M110.

Swing down halfway to the horizon to look for M33, which is one of my "calibration" objects: If I can see M33, then I've got a reasonable chance of picking out other difficult objects.  Align on the pointed tip of the Triangulum asterism and begin to star hop up and to the East but the cirrus is getting in the way.

By now it's well past 10pm and the skies are as dark as they are going to be, with the moon not far from the Eastern horizon and the ever increasing threat of cirrus, I'm thinking this might be a bust.  I stood back from the eyepiece to look around and cursed the line of cirrus hanging there from the South round high in the East and heading to the North, just to the North West of where M33 should be.  I decided to wait 5 minutes to let it pass and after a while, I realised it wasn't moving and that it was in fact the MilkyWay!  I think the hedgehog shuffling around in the bush learned a few choice Anglo Saxon words as I went back to the eyepiece, this time, to find a gorgeous M33 fully visible even without averted vision.  Spending time on M33 is really worthwhile as there is so much detail that can be teased out under good conditions, so I let as many photons tickle my retina as I could; just about seeing structure with arms sprawling out from a grainy central fuzzy core.

Having satisfied myself on M33, I swung up towards Cassiopeia in hope of finding some of the much fainter NGC objects in Triangulum and Andromeda, but alas, came up blank.   Down to Perseus and the double cluster is visible to the naked eye as a faint grey smudge and two grey smears in the finder scope.  Lovely view through the dob.

West to look for the Heart and Soul nebulae, but knowing that these will be difficult to find in the scope as they are so diffuse.  Nothing shows and the stars in the MilkyWay are fading.  I looked up and a shelf of cirrostratus was moving in from the west getting thicker the further west I looked.  Ursa Major was gone and within a few minutes Cassiopeia was fading too.

I waited a few more minutes hoping a break might form, but when the moon appeared above the horizon, I knew it was time to call it a night.

Lesson learned: always keep an eye on the sky: that bank of cirrus cloud might just be a galaxy!

(and I must apologise to the Hedge Hog when next I see him)

Richard

 

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Sounds like you have some decently dark skies when the clouds play ball Richard, nice one.

Have you picked out NGC604 in M33? It is a bright Nebula in the spiral arms, I’m sure you will have seen it before, even if not identified specifically.

FF0A16AC-67E9-43DC-BCBA-F7E0E31F1134.png

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1 hour ago, Stu said:

Sounds like you have some decently dark skies when the clouds play ball Richard, nice one.

Have you picked out NGC604 in M33? It is a bright Nebula in the spiral arms, I’m sure you will have seen it before, even if not identified specifically.

 

Yes our skies are really good.  According to Clear Outside, my estimated sky quality is 21.33.  A couple of years ago the Council changed the street lighting in the village to LED, which made a tremendous difference, particularly away from the North.  To be honest though, I haven't calibrated that number as it only takes a neighbour to turn on an outside light or the farmer to be out with a nightsun and I'm dancing around trying to find shadows.  I tend to use feint and tenuous objects such as M1 or M33 through the stock 25mm eyepiece on the 200p as my "calibrator" for what I might observe on any given night.

I've definitely seen several brighter patches in M33 through the eyepiece.  On the best nights, the central part appears to be slightly mottled and the outer structure has brighter blobs of fuzziness.  I can't say for sure if anyone of those is NGC604 or any other active region, or indeed just a greater concentration of stars within the arms, but they don't appear to be local stellar objects, because they don't resolve to a point of light.

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Your skies sound excellent, very jealous! NGC604 is the brightest of the M33 nebulae as far as I'm aware, should be possible to identify it from the others, loosely at the opposite end from mag 8.1 HD9483

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