Thor's Helmet 14 min snapshot with a 79" RC scope

[gorann]

On the 24th of January 2017, some user of the Liverpool Telescope decided to spend a few frames on Thor's Helmet. This is the only data on this object in the LT database and it consists of seven 120 s exposures, 3 with a Ha filter and two exposures of each of Bessell V (green) and Bessell B (blue). That is not much data but also not much work to stack, so I had a go at it. So this is a 14 min HaGB image. Thus, I put the Ha data in the red channel (since there were no red filter data), which probably explains the slightly unusual colours. All done in PS CS5.

This is of course a rather noisy image (pixel peepers should stay away) compared to the Little Dumbbell that I recently posted with 3.6 h of LT data. Still, I am slightly amazed what a big scope can collect in 14 minutes.

The scope is a 2 m RC f/10 (so 20 m focal length!) equipped with a 6 x 6 cm (15 µm pixels) 18 Mpix CCD camera (normally run at 2x2 bin) of the brand e2v, which I think is chilled to -100°C.

 

 

 

[bottletopburly]

Looks superb to me 

 

[wimvb]

Great result with limited data.

The background looks a tad green on my huawei screen. Maybe a dose of hlvg will cure that.

[gorann]

6 hours ago, wimvb said:

Great result with limited data.

The background looks a tad green on my huawei screen. Maybe a dose of hlvg will cure that.

On mine too after I uploaded it, so now I used curves on the green histogram to bring down the green tint a bit (hlvg does not work on Mac) and edited the image in the post. Thanks by the way!

6 hours ago, bottletopburly said:

Looks superb to me 

 

Thanks !

[Rodd]

What is there to say--a 79" scope!  Perhaps a tad too much noise control?  If you did not use any, then it must be something else I see.

Rodd

[gorann]

Just now, Rodd said:

What is there to say--a 79" scope!  Perhaps a tad too much noise control?  If you did not use any, then it must be something else I see.

Rodd

Yes Rodd, I have to admit I used a bit of noise reduction to make it presentable. With only two subs on two out of three channels the S/N ratio suffer. The LT data on objects with more data can be amazing and not in need of noise reduction (like in my Little Dumbbell post), and I am not going to bother processing any more such short LT exposures - this was just an experiment