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My first imaging attempt


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I've been a bit quiet recently. Been feeling rough, but after a hospital visit, I'm well on the mend. Spent far too long thinking a blood clot in my leg was just a bruise!  :o
Well, I tried a bit of imaging with itelescope. This was all rather different from anything I had done before, but was very enjoyable. I used a Takahashi 150 with a one shot colour 8.3 megapixel SBig on a Paramount GTS in New Mexico! Reserved a slot for 10pm local time (about 5am our time) and programmed what I wanted the imaging rig to do, and went to bed. Got up the next morning fully expecting I had bodged it all up and got nothing. I was pleasantly surprised and rather excited to find it had all worked perfectly. :)
I got ten 3 minute subs. After Damian (Damnuut) had kindly pointed me in the right direction, I managed to stack the images in DSS and play around with the curves in Photoshop. Definitely a new learning curve for me, and I still don't really know what I'm doing. But if I can do this, anyone can.
I chose a two-for-one favourite of mine, and had calculated that it would suit the field of view of the imaging system.


My first attempt is the cluster Messier 46 with planetary nebula NGC2438 in Puppis, which I had previously enjoyed visually many times. Through the eyepiece, the planetary shows as not much more than a smokey fuzz ball about 1.5x the diameter of Jupiter, so I was very pleased to bring out some colour and detail. You can zoom into the cluster quite deep for a closer view.
The cluster is about 5500 light years away and the planetary nebula about 2900 light years, so they are not associated. The nebula is superimposed on the cluster in the same line of sight. M46 is 6th magnitude and the nebula is 11th. M46 forms a nice binocular double cluster with the slightly brighter M47 about 1 degree away and crosses the meridian in the south at 10pm at this time of year at a respectable 22 degrees above the horizon. More like 43 degrees from New Mexico. M46 was discovered by Messier in 1771, but William Herschel was the first to spot the planetary nebula in 1786. This planetary nebula has a central star which is one of the hottest known at 75000 degrees Kelvin on its surface. It is a magnitude 17.7 white dwarf star. All the stars in the cluster are receding from us at 41 km/sec and the planetary nebula is receding at 71 km/sec. The field of view shown by the main image at the distance of the cluster is roughly 40 light years across containing over 500 stars known to be cluster members. There are about 180 stars brighter than 13th magnitude in this  cluster, in a region the size of the moon. So on a clear night, it makes a fine sight in any telescope, especially with the added bonus of a planetary nebula. In smaller scopes the nebula will dissappear into the forest of stars, but it will take higher magnification well and should then be visible at least as an out of focus star.




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Yes, glad you are on the road to recovery.

Also nice image and fascinating narrative too. Thanks. I'll look iut for this.

Do you feel the satisfaction of having captured a great inage, or do you feel some remoteness from it?


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Guest Tweedledum

Hi Pete,


That's looking good,I've been having a play with the data. But in essence its just practice now that you are in go mode. Try just a tad of unsharp mask!.


Glad the leg is getting better, I had visions of andy's mum when you said it was a dvt...Now amassing  some kit so hopefully you can come over to the coffee shop and we can sort some of it out. :D

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Thanks very much for your concern everyone. I had a second ultrasound scan on Friday and things are looking and feeling much better.

Do you feel the satisfaction of having captured a great inage, or do you feel some remoteness from it?


I do feel a lot of satisfaction and also feel very pleased about the remoteness :) When I eventually capture a great image I will feel even more satisfaction :) This remote imaging certainly pushes my buttons.

Remember that I have never done imaging before (strictly visual). So for me, this is all very new and exciting.

I am more than happy to avoid the expense of purchasing AP equipment, the hassle of setting up, polar aligning, guiding, troubleshooting it all and freezing, only to often have to pack away early due to cloud. The processing learning curve part of this is as much as I want to try and tackle.

I'm just thoroughly enjoying having a go at this the easy way. I can select any top spec imaging system from about 15, book a time when it is free maybe a day or two ahead, tell the scope exactly what I want imaging and how I want it done (subs, darks, flats, bias, and filters - once I get to understand it a bit more) and then wake up to my raw data all ready to download. If it is cloudy, or the scope breaks down, I am charged nothing and can reschedule. My thirty minutes on M46 using nearly £20,000 worth of equipment cost me less than a fiver! The bigger more sophisticated setups would charge up to several times that for the same time, but then we are looking at £100,000 setups! The set up time was about 10 minutes on the laptop and the processing took longer since I'm learning how to do it. It is also teaching me a little more about the technicalities you imagers are posting about.

I do have tremendous respect for all you 'proper' dark siders who do it all from scratch and climb the full learning curve to perfect both your own equipment and imaging techniques. That really is awesome stuff :)

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