A Night in the Life of Welford Observatory

Having received gifts for my interest in astrophotography this Christmas I was sure it would be cloudy for at least a week - giving no opportunity to use them as that is what usually happens in this hobby.

I thought I'd record an entire imaging session as it looks like I'll have an entire night of data to work with tomorrow when I can record the process for anyone just starting out in astrophotography. Be warned...I may get it wrong, but its a reference point.

I was surprised to see it would be clear tonight and have set up to image.

Here's the gift I received



It's a bahtinov mask that aids in focussing the telescope with the camera attached. I had been using one that I wasn't sure was designed correctly for my scope aperture - it appears it was close but the difference wouldn't have meant blurred images.


With the mask attached you move focus in and out to centre the spike in the middle. This give a really good (not perfect) focus. There are programs you can use to get focus even better but I've never had any problems using the bahtinov mask - you can read more about it here.

Next it was time to get the scope guiding on the first imaging target for the night - the Wizard Nebula in Cepheus. The orange square represents the field of view covered with my scope/camera combination.


Image courtesy of Starry Night Pro 7

Checklists should be an important part of an imaging session. I intend to make a few as I started an imaging run in H-alpha only to notice that I hadn't calibrated the guiding?! Luckily I noticed almost immediately and set it on its run.


26/12/16 1952hrs

I've been imaging for about 2 hrs now and have captured 12x5min subframes in H-alpha and 12x5min in Sulfur II. I'll finish with an hour in Oxygen III and then move on to the next target.

Image courtesy of Starry Night Pro 7

26/12/16 2129 hrs

I've chosen my next target.

NGC 1499 is known as the California Nebula and is found in the Perseus constellation. This emission nebula is caused by xi Persie which is also known as Menkib.

I've imaged this object quite often with my "one shot colour" camera (QHY8) and was fascinated by the billowing nebulosity found in it. Having only imaged it in RGB I've been looking forward to capturing the H-alpha that is abundant in this region. Early indications are I won't be disappointed, the image below is a single 5 minute exposure in Ha - which is pretty impressive...take my word for it lol.


I'll concentrate on Ha tonight as I'm not sure how much Oiii and Sii will add to this object.

The camera attached to the back of the telescope is doing a great job of letting me know when it's time to spin the roof to move the opening along as the stars pass overhead.


I used to simply time it but that was a bit hit and miss but as it give me a view "right down the snorter" of the scope I can't go wrong now :-)

As the object moves eastwards its coming closer to the increased light pollution on the horizon. You can see the light pollution in the image below.






WOBSCAM (as I've christened my scope monitoring camera :-) ...is also capturing Messier 45, the Pleiades which is kind of cool. It's surprising how bright they are in relation to the other stars in the neighbourhood.

You'll notice the aperture the scope is looking through has increased. I took the front hatch cover off so the scope can track lower to the East.

26/12/16 2354hrs
On to another object. Can't believe my luck!

Image courtesy of Starry Night Pro 7

The Flame and Horsehead nebula in Orion are very popular objects at this time of year. Its a favourite image of mine that I captured with my QHY8. It's great to be able to try out the new mono camera on it.

Here's a short 5 minute capture taken while I was framing the shot.


This shot was taken with the Luminance filter, the Ha filter is reveals far less detail at these settings.

After getting the scope going again I had a look at WOBSCAM and noticed that Orion was quite clear in the view. The area I'm imaging is just by the left most star in Orion's belt. You can also make out the Orion Nebula (Messier 42). I hope to image that soon as well.


The light pollution is quite bad in the South here (the town of Wantage) but this object is sitting just above it I and I've managed to image this object before successfully.


27/12/16 0954hrs Update 

I finally got to bed at 0300hrs having imaged 3 objects in one night (not all the data I need for two of them but a very good start.

The great thing about my new camera is that I can leave it hooked up to the scope in the observatory without fear of condensation building up in it. My last one was awful for that and great care had to be taken.

This means I could take my flat field images in the morning. The image below shows a flat for Ha. This image will be subtracted from all the subs I captured last night - removing "dust bunnies" and other errors.




I take 50 for each filter (last nights consisted of Ha, Oiii and Sii)

One issue I've been trying to deal with appears in the image below. I took the flats for the three narrow band filters without the banding shown. 



They've suddenly appeared on the Luminance flats (taking them now for convenience even though I don't need them etc.)

When I turn off the dew heaters for the telescopes they go away (see below)



Its fairly simple to establish that as the dew heaters are running off the same supply as the camera it could be causing this interference. However, it doesn't happen all the time so I'll have to do some more troubleshooting. For now I'll just turn the dewheaters off and hope the scope doesn't mist up.

The next step will be processing - but that will have to wait until I have got to the gym to restart my system following all the food I've eaten during the holiday season LOL!

27 Dec 16 - 2128hrs

I've spent most of the day processing the results from the Wizard Nebula taken over two nights (30 Nov and 26 Dec)

I learned quite a bit about how to process data from different nights but it took a looong time :-)

First I pre-processed the Ha, Oiii and Sii channels producing 3 "light" frames to combine.

The initially start out black and white as below, with varying levels of detail dependent on the wavelengths present in the object being imaged.

This first light frame is the Sii channel - not a lot going on here 



Next is the Oiii channel ...little more detail in this one



And finally the Ha channel where all the detail has been hiding :-)




These three images are combined in PixInsight using PixelMath where you put varying weights for each channel in the R, G and B channels creating a false colour image.

I used the following weights which were suggested to me by Patrick Gilliland on the Stargazers Lounge forum. 

(MASTER_Sii_161226_r*.90)+(MASTER_Ha_161226_r*.10)

(MASTER_Ha_161226_r*.85)+(MASTER_Sii_161226_r*.15)


MASTER_Oiii_161226_r

I had absolutely no idea how to apply the weights so this was a huge help to get started.

...and here's the final result.



Like you I'm not crazy about it either :-) I assume I simply need to get more data on it but to be honest I find this object pretty boring for some reason....after capturing and processing the Elephant Trunk Nebula with such great results, and knowing that I've got tons of data on the California Nebula to process, I'm going to leave this object for a while and concentrate on others.

Any advice on how I might improve this image would be really useful.

Now I can finally  get some sleep :-)