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I decided to take this image of the open star cluster NGC884 with the goal of practicing my star field processing technique Basically, I think my star field images can be improved mainly in the sense of getting better colour into the core of the stars.
For this image I tried several different approaches before settling on a DDP stretch of the Lum and RGB data which I then blended via PS Screen with some slightly stretched linear RGB data to get colour into the star cores.
I set the exposure at 120s which gave a result such that the pixel level was just below my cameras non-linear region for the bright stars.
LIGHTS: R:20,G:20;B:12 x 120s, FLATS:30, BIAS:100, DARKS:40 all at -20C.
I find star fields quite challenging to process, so I decided more practice. My attempt on the open cluster NGC884 is shown below. Since the object has some quite bright stars I went for a 2min sub exposure to ensure that I was below the non-linear region on my camera. I decided to go for a LRGB approach with a synthetic luminescence. The image represents just below 2 hours integration time.
I'd appreciate any constructive comments.
LIGHTS: R:20,G:20;B:12 x 120s, FLATS:30, BIAS:100, DARKS:40 all at -20C.
I took these images on Sat 25th Nov from here in W Oxfordshire. I've got the widefield setup running now using a RPi3 running KStars and Ekos. This controls a modded, uncooled 350d (with Baader filter) and a serial shutter cable, an Arduino motor focuser (as a Moonlite compatible focuser) and the Losmandy GM8 it all sits on.
Images were taken through a Canon 85mm f1.8 EF lens at f4.5, exposures were 45 x 300sec (3h45m total) at ISO400 through an IDAS P2 filter. The field is a whisker over 15x10 degrees. Processing was in PixInsight and a bit of work in Photoshop to reduce a bit of amp glow that didn't calibrate out fully.
Fairly pleased with this (though the Heart and Soul have come out maybe a little red - the colour calibration uses PI's PCC tool, and the IDAS filter might throw it a bit), but there's some other areas of interest coming through in the image. Annotated image attached but there are a few other bits that PI doesn't grab - there's a small area of reflection nebula (LBN 142.14+01.97) to the left of Sh2-202 that's just coming through. Also, unlabelled are Stock 2 (between the Heart and the Double Cluster) and for the interested clouded out astronomer, galaxies Maffei 1 and 2 are visible in frame just below the Heart (labelled as Sh2-191 and Sh2-197).
Thanks for taking a look!
Astronomical twilight ends 6:18pm
Transparency: 4/5 to 3/5 (above average to average)
Seeing: 3/5 (average)
Location: Fort Collins, CO
Elevation: 4997 ft. (1523 m.)
Bortle 6 to 7 skies depending upon which direction you're looking.
The Double Cluster is pretty clear tonight. I can see it in my binoculars as well.
M31 is very clear, and in the Binoculars as well.
I then try and catch M8 which is just barely above the building down the hill from me. The time is 5:40pm MST. M8 gives up it’s nebulosity only using the LP filter I use. Orion UltraBlock Narrowband LP filter.
I find M20, M21, M23, M10, M24 with my telescope (8SE) and then:
At 6:15 pm, I go for M22, this is a new object for me. M22 is nice and clear, with good granularity, and some individual stars using the 17mm which gives me 119x. This is usually the best globular cluster eyepiece so i leave it in there for the next object. But before I do that, I decide I’m going to find M22 with the 10x50’s using my red dot star pointer. Note: The nice 9x50 RACI finder scope I’m thinking about will not be usable in this way like the crappy little star pointer does. A telrad would be nice I suppose and certainly it's clear why people like them. I'm just looking into making my 8SE non-GOTO (because I'm clearly a star hopper at heart and really want a 16 inch minimum travel dob from Hubble Optics). We shall see if i really even need to do that since I'm actually successfully using the 8SE to teach me the sky. Since I'm taking notes and all.
I actually am able to find M22 with my cheap 10x50 bino’s. Fuzzy little ball but definitely there and visible to my binoculars.
Next up: M55. It’s roughly 6:27pm MST and I continued through my list. M55 is a nice bright glob tonight. I get down and peer through the star pointer and gauge which section of sky I’m looking for and stand up, put the bino’s to my eyes and with very little searching I found M55!
Next was M25, not sure I found that with my binos really.
Then I was at M18, M17, M16 all three were lovely. It was roughly 6:48pm by then. Because I was mainly looking for nebulosity I didn’t try these three with the 10x50’s. I’m sure i should have.
I catch a glimpse of M76 when I thought I was slewing to M16 in the prior group. I thought, what a waste of battery power. I looked at it briefly, and slewed back to the object on the list, M16.
Next was M11 which I then found with my 10x50’s. A nice little dusting of stars in the binoculars!
Following that was M13 which gave a particularly clear view this evening. I have been looking at star charts for quite a while now, and I have something of a photographic memory (comes in handy during band practice!). So I used the star pointer to give me the section of sky. This section of sky is really hard to look at and not loose your dark adaptation. I use an eyepatch and a black t-shirt pulled over my head backwards as a hood to keep stray ground light out. But trying to find something in the sky and star hop to M13 seems really not doable to me. However, the star pointer does show me where M13 is and I find it easily between Eta and Zeta Herculis. Just southwest? Of Eta Herculis.
Now, this is the cool part. Because I’ve looked so often at the Hercules constellation, I had a good idea that you just went back to Eta and then you could find M92 between Eta and Iota Herculis. Slightly more than halfway.
And there it is, a short star hop after finding M13, I find M92 without the telescope helping me. From a star chart in my memory. Awesome.
Emboldened by this additional object added to my list of things I’ve seen with my 10x50 binos, I went back to Cassiopeia and hunted around there using the 10x50's to look for NGC 663 and NGC 7789. I definitely see NGC 663. I find M45, Hyades, Aldebaran, I use Delta and Gamma Cas to point me towards NGC 884 and NGC 869 aka the Double Cluster. As always, it is beautiful to see. I really like the 10x50’s. Really looking forward to the 20x80’s I’m getting next.
Next I aimed my 8SE towards M57. I tried to see that with my 10x50’s but couldn’t. I thought I did but couldn’t confirm it.
About 7:30pm MST I slewed over to M56. This is a nice Globular. Bright, granularity, some individual stars. Very nice. I go for this one in the bino’s and there it is!
At 7:39 or so, M27 was up in the 8SE and i tried for that with the 10x50’s and I do believe I found that as well!
M71 right after that, and yes, I did in fact use the 10x50’s on this object and found it as well. From M71 I found the Coathanger Cluster. So there are a couple new, easy to find (i think) objects M27 and M71 between Deneb and Altair just south of the coathanger cluster. I’m sure I can do better at star hopping but this is a lot of fun making my 8SE actually teach me something.
M29, the cooling tower, very nice in the scope, very not found in the bino’s. I’ve been looking for this object in the binos for a while. It’s pretty easy to know where it is, there all close to Deneb and all. It being just south and above of Gamma Cygni. But seeing the cooling tower in the 10x50’s might be impossible. Maybe the 20x80’s.
I went on to M15 around 7:43 pm MST. Very bright! Wow, this is amazingly bright! I handily found this in my binos as well!.
M2, M73, M72 all found first by the 8SE and then by star pointer to my binos.
Right at 8:00 pm MST I saw M30 on the list. I know this is a new object. So my crazy memory tells me. So i slew to M30 and gaze upon its beauty for many minutes in the 8SE. I find it easily in my binos with the help of my telescope.
Last couple objects on the list:
M77 - 8:09 pm MST this is only visible by slewing the telescope and introducing motion. I did not find it with the 10x50’s.
M76, which was given a glimpse earlier was not findable by my lazy, about to call it a night, eye.
The temperature was 36 degrees and my hands were beginning to hurt from the cold a bit. The thought of going inside and playing guitar instead of freezing in the somewhat stout wind (6 or 7 miles per hour) is probably why I couldn’t find the little dumbbell nebula.
I see one object on my list from that night I skipped. M34. It keeps getting on the list then falling off at the last minute… it’s still early in the season for that object though. Although I didn’t even stay out long enough to see Orion coming up (over the tree).
I thought to myself, as I packed things up around 8:20pm MST, that was a pretty short session. But it was action packed with lots of new bino objects found!
Tonight (11-14-17) the transparency is “transparent” it is supposed to be cloud free but the seeing is bad (1/5) to poor (2/5) and 20 mile an hour winds. So no star gazing with anything but Binoculars in a parka on a zero gravity chair for me tonight.
I'll let you know how many of those new targets I can see tonight. Pretty sure I’ll be able to find M13 and M92. M27 and M71 will be trickier But I think I can find M30 again.
I'm going outside to try in a few minutes here after I post this.
This started on 10/31/17
I had set my 8SE up at around 7:00 pm
Transparency: above average 4/5
Seeing: average 3/5
I viewed a number of objects with my 8SE:
M110 was not able to see.
M57, M27 are always available.
M13, M92 sitting very pretty in a clearer patch of sky than usual to the west.
I was early enough to catch some favorites, M8, M16, M17, M20, M21, M22, M23, and M24
I then took a break and when I came back I grabbed my binoculars, 10x50's.
First I viewed Pleiades, then Hyades, then over to Mirach, Nu, Mu, and above that to M31. I couldn't see M110 or M32 in binos.
I've been searching for Kembles Cascade with binoculars, which I've found with the 8SE, though you can only see two stars at a time at that magnification and narrower FOV.
So I'm looking around the general vicinity below Cassiopeia, in Camelopardalis and eventually wander into Perseus and find:
The Double Cluster with my binos.
I slewed the 8SE over to NGC 884, and NGC 869 to confirmed that I had in fact found the double cluster in my 10x50's
I finished my bino tour of the sky on the Coathanger Cluster.
I have never viewed the Coathanger cluster through my telescope. Well, maybe once just like M45 and Hyades. I always use binoculars to look at these objects now.
I finished the evening on M42 which I end up looking at for nearly an hour through both the binoculars and my 8SE