Thursday, 11 January 2018

Capturing a Pinwheel and a Monkey in tonight's sky

Of course I will start this post with usual heading....

It's been quite some time since we've had any clear night skies to image under. Looking at my computer when starting up the observatory tonight (7 Jan 17) I noticed the last time I had used it appears to have been the 16th of November. Depressing.

Here's a screenshot from my favourite planetarium software - Starry Night Pro 7 - of what the sky above the observatory was populated with tonight.

Courtesy of Starry Night Pro 7

I tried to make the most of tonight by imaging two objects.

The first was the was a spiral galaxy in the constellation Triangulum called the Pinwheel Galaxy or referred to by it's Messier catalogue name - M33. The constellation can be seen in the shot above in the upper right.

I've always found this object difficult to image. Previously I'd attempted it with my one shot colour ccd camera - and frankly I got better results than my effort tonight :-) (see the deepsky gallery under astrophotography on my website @

However, I learned a bit more about LRGB imaging attempting this object tonight. I really didn't have enough time to capture the data I needed on it before it moved out of range of the observatory though so results are poor at best.

Messier 33 - the Pinwheel Galaxy in Trangulum

Although I considered getting another one shot colour ccd (namely the ASI1600 MC) I think it will be worth persevering with mono LRGB as better results can be obtained with patience.

Here's the capture profile for the image above

Disappointment over I moved on to the highlight of the evening. Narrow band imaging is always my favourite now as the detail that can be captured is amazing.

Tonight's object was NGC 2174 - the Monkey Head Nebula in Orion. I've never imaged this before so I was really looking forward to it.

Again - not really enough time on this to make it useful (see stats below) but it was fun capturing what I did and processing it afterwards - always an learning experience using Pixinsight - every time! :-)

As ever it's worth clicking on the image to see the full resolution results

Sii, Ha, Oiii (SHO or Hubble Palette)



H-Alpha and Oxygen iii

H-Alpha and Oxygen iii

I will of course image this monkey again and hopefully add to the data I've captured (always tricky to get it lined up the same way on multiple sessions)

I have an all sky camera that I use to keep an eye on the weather while I'm in the house. It captured this shot while I was imaging the monkey and it's full of interesting objects (if a little out of focus :-)

Thursday, 16 November 2017

A shot at the Heart and Soul....nebulae

Tonight’s target has a few different common names besides the usual “Heart and Soul”. “Valentine Nebula”, “The Running Dog Nebula” and the ever catchy “AFGL Cloud” are some that refer specifically to the Heart element of this structure.

Of course, galactic catalogue names are the easiest way to find these objects on star charts and computer based planetariums.

Where the Heart and Soul nebulae are concerned the catalogue designations refer to both the nebulae and the star clusters they contain.

Heart Nebula: IC 1805
Soul Nebula: IC 1848

As these nebulae contain star clusters their distance from us is known to good deal of certainty. Located in the Perseus Arm of our galaxy they appear to be around 6000 light years away or around 1,850 parsecs (one parsec is the distance a star shifts in arcseconds when viewed from opposite sides of our orbit around the Sun.)

I am using my Teleskop Service 65mm astrograph with a ZWO ASI1600MM camera. With this configuration, although widefield for my observatory, I will have to shoot each object separately and then create a mosaic. This is something I’ve never attempted and give that the weather will prevent me shooting both objects on the same night, I can see this project may take a number of years. This also means that I’ll have to be a little more disciplined in naming the sub frames so that I can process more data into them at a later date.

2000hrs 16/11/17

Well, the skies of course didn't clear....

But I used the time to check a few things and practice framing this object on the sensor and found it really difficult with all the high cloud around.

First I wanted to see if the Ha, Oiii and Sii filter were parfocal. I'd heard that these ZWO filters were but never checked.

Here's the results with a Bhatinov mask as a focusing aid




I think that focus is close enough for my work with these filters. Technically I should slew away from the object to a bright star, refocus on each filter change then command the scope to return - but my fear is that it won't quite frame up right again - so this level of focusing accuracy will have to do.

Another issue I have to investigate is the blobs of frost forming on the camera sensor as it cools down to -30c

The dissipate after about an hour and appear to be forming on what I think are dust motes on the sensor. 

I have to figure out whether I should take the camera out of its air tight container and get it on cooling immediately or let it reach the outside ambient temperature and then start cooling. 

I think its the former as I tried the latter tonight and it didn't seem to work - although I'm not sure it reached ambient temperature either.....

As you can see in the image above I barely got any nebulosity on the picture after a 10 minute exposure using the Luminance filter. Not sure if that was due to clouds or this object is just that faint? The image is useful for helping me frame next time as I've got a better idea of where the star cluster and bright area of nebulosity at the bottom of the picture should be....I need to move both to the left in the image - almost to the top.

So not a complete waste of an evening, the weather could've been to forecast but that rarely happens.


Saturday, 4 November 2017

October Andromeda Galaxy Processing (Cont'd)

A really difficult thing about the long hiatus of imaging during the summer is that when I am able to start again in the Fall I haven't got a clue what I'm doing when it comes to processing the data.

I seem to have re-learn everything - although I do have procedures written down that I follow.

And so it was with my 4.75 hours of data captured on the Andromeda Galaxy. 

I've been through 3 full day long processing sessions on this to get it where it is...and I'm still not completely happy that I've done my best.

Thanks to the guidance from my friend Nick and the members of Stargazer's Lounge that critiqued my work, I do think this version is not to bad now.

Here's the specs on the data capture

Object name
Andromeda Galaxy
Object ID
11, 12 and 15 October 2017
Altair 115mm
89 x 1 min = 89 min
16 x 2 min = 32 min
24 x 2 min = 48 min
28 x 2 min = 56 min
30 x 2 min = 60 min
Total time
4.75 hrs
PixInsight / Bias, Flats, Darks / no noise reduction / no masked stretch (manual)

I used Pixinsight to process this an found PixelMath invaluable in combining the Ha and luminance.

I didn't use Linear Fit as I thought (wrongly as it turned out) that it was killing colour in the images)

I did use BackgroundExtraction, DBE, MorphologicalTransformation, HDMultiscaleTransform, PixelMath for the Ha effort on red channel

Here is the LRGB version (Luminance, Red, Green and Blue channels)
Be sure to click on these and open them in a new window to see it in full resolution

and here, disappointingly, because I don't think I got the H-alpha channel processed correctly, is the HaLRGB version. This is meant to highlight the regions of H2 in the galaxy arms where star birth is taking place. It achieves that but there is the mirky smear of gunk across the rest of the galaxy. I will no doubt need to try again :-)

I've thoroughly enjoyed trying to process this data and feel that I've got back in the swing of it for the coming season. At 4.75 hours I think that's quite enough time on M31 with the 115mm scope, now to point the 65mm wide-field scope at it ....if the weather permits before Andromeda disappears into the West as winter approaches.

Saturday, 21 October 2017

IC 1396 Elephant Trunk Nebula - Unprocessed data discovered

I used my new ASI1600MM mono camera for the first time back in November of 2016.

The whole point of moving from my QHY8 colour camera to the mono was so that I could do narrow band imaging.

IC 1396, the Elephant trunk nebula was a perfect first target and remains the best astro image I've taken to date.

Here's the Hubble palette version followed by the Ha image I captured on my first outing with this great new CMOS camera

After processing my data from my imaging session on M31 recently I found a folder of LRGB data on IC 1396 that I shot a couple of days before I received my narrow band filters.

It seems that in the excitement of attempting my first nb image I completely forgot about the LRGB data I had captured.

Today I processed that data and, while it doesn't compare in the slightest with the quality of the nb results, it did highlight a few things.

Here's the result of the LRGB 4 hrs of data.

Now, compare this to my best effort on the QHY8 colour image (I know others probably could've done better, this isn't a contest between the two camera's, it's a contest between my imaging expertise)

My first reaction was I like the colour of the QHY8 image more - but - the only reason it's that colour is because, if  you look closely at all the orange stars etc., it is clear I hammered the red channel to make it look that way - so I effectively "painted" the image - which is not good.....

Here they are side by side and scaled

Open that image up and have a good look at the one on the right - the QHY8 example - it's almost comical how much I pushed the red channel to make it look red...whereas the one on the left has a more "natural" feel to it with actual white stars haha.

The other message I took home from this is that there are objects in the deep sky that are more suited to narrow band imaging - I could capture LRGB for weeks and not match the nb results on this object.

So although the forgotten data has been processed, and I believe it's better than the QHY8 effort, it seems that the reason it was unprocessed is that I saw the results from nb and canned the LRGB lol! 

Nothing lost today, as Captain Mainwaring said when asked why he learned to play the bagpipes on his honeymoon in Scotland, " was cold...dark, there was nothing better to do..." LOLOL!

Saturday, 14 October 2017

M31 - The Andromeda Galaxy

This imaging session, occurring over 2 nights was not without its mistakes and confusion! 

Setting up the first night I seemed to spend most my time trying to remember how to configure the capture software correctly.

The second night I decided not to connect the guide camera to the PhD Guiding 2 correctly and spent 30 minutes establishing that fact.

However, out of the jaws of chaos (which extended to the processing of the image) came one of my better efforts on this object. It’s also the largest amount of data I’ve collected with almost 5hrs going into the can for processing.

I’m having fun zooming in to the different parts of the galaxy to view the H2 regions (star forming) that I was quite surprised to have caught in such numbers. These regions, swimming amongst the sea of big, hot blue stars destined to burn out quickly, are similar to our own Orion Nebula. Moving to the core of the galaxy and it super massive black hole the cooler, longer lived red stars dominate.

Up to the left M110, another galaxy bound to Andromeda has resolved quite well – it can off look very pixelated – and nearby the big blue star who’s name I cannot find 

This galaxy is 220,000 light years across and contains a trillion stars which is twice as many as in our Milky Way galaxy.

I think I need to capture a lot more colour data but this is a good start.

Tuesday, 12 September 2017

The Pelican Nebula Project - Part II

See the previous post about the Pelican Nebula

I managed to subtract -24 degree dark frames from the sub-frames used in that image and the difference is really rewarding.

The glowing edges are gone and I managed to pull more detail out.

Now on to Part III where I'll add Sii and Oiii to the Ha seen below.


Tuesday, 29 August 2017

The Pelican Nebula - IC 5070

The nights are getting dark just early enough to be able to get some imaging done between 10pm and 1am.

I managed to image the Pelican Nebula in the constellation Cygnus last night.

It was a very warm night so the camera didn't get down to ideal cooling temperatures (only about -26c) but it had been a very warm day so that was expected.

This is just a start of a narrow band project (Ha, Sii and Oiii) that I'll be working on over the coming years. And it will take years with the weather we've been having.

I was really pleased with the results of 11 x 5min sub frames. I've used flats but not darks on this so far - I need to create some darks around -26 degrees as I didn't have time on the night.

I've created two cropped images of the main one as they show some of the intricate detail waiting to be captured in this object.

As ever its worth opening these to view in full resolution