Pelican (head and shoulders)

[alan4908]

Inspired by the recent Pelican image by  @steppenwolf I decided to have a go myself. Since it was near full moon, I decided to use only Ha and checked via CCDNavigator that the object was a sufficient angular distance to allow imaging (for those that might be interested I use the so called Lorentzian "moon avoid" technique developed by the Berkeley Astronomical Department). 

I was quite impressed by the image details. 

Alan

LIGHTS: 8 x 1800s Ha; DARKS: 30, FLATS:40, BIAS:100 all at -20C.

[Astroboy239]

Great image nice detail. Which ota and camera did you use? 

[alan4908]

23 minutes ago, Astroboy239 said:

Great image nice detail. Which ota and camera did you use? 

Thanks for the comment. It was captured with my Skywatcher ED 80 DS Pro (with a x0.85 FF/FR) and a Trius 814 camera.

Alan

[laudropb]

Very nice image.

[steppenwolf]

Very nice indeed and some great detail in the 'pillars'.

[Stub Mandrel]

3 hours ago, alan4908 said:

Lorentzian "moon avoid" technique developed by the Berkeley Astronomical Department). 

Google is no help - can you give more information?

[toxic]

very nice indeed 

 

[Mr Spock]

Really good image with lots of detail. Nice one

[alan4908]

Thanks for all your comments. 

On the subject of the Moon Avoid technique:

1 hour ago, Stub Mandrel said:

Google is no help - can you give more information?

Both ACP Expert and CCDNavigator implement the Lorentzian algorithm so with a few clicks of a button and for a particular object, you can see if it is OK to image or not.  If you want more details then I suggest you download the trial versions and go to the help section and search for moon avoid. I'd recommend both of these software packages, particularly if you'd like an easy life when imaging  

For those interested in a bit more detail,  the ACP implementation takes two parameters: the minimum angular distance you can be from the full moon (call this Min Distance) and the so called "width" of the Lorzentian function call this WIDTH. So, with an image credit to Bob Denny and Dick Berg you can visualize how this works by looking at the following graph of the Lorentzian function that is plotted for a MINIMUM = 60 degrees and three WIDTHS of 5 (blue), 10 (red) and 15(green). Here, a full moon occurs at 15 days and a new moon at 0 and 30 days.

 

To take an example:   say, you had set your system up so that when using an Ha filter you had set a width of 10 (red curve) and a minimum distance of 60 degrees.  On a particular night,  say the moon age is 5 days, if you look at the graph (red curve)  this means that the object you wish to image must be more than 30 degrees away from the moon. 

I currently have ACP configured for my Ha, OIII and SII filters to 60, 120 and 60 minimum separation, respectively,  together with a width of 14. These are the ACP defaults.  So, I'm basically following close to the green curve for my Ha and SII filters. 

The idea is that you can fine tune the minimum distance and width parameters to your particular system and your imaging objective  (deep space, supernova search etc).  I haven't tried this yet, mainly because of the lack of clear nights in the UK !

Alan

 

[aparker]

Beautiful image.  Love the tight stars and super-crisp detail.  Really well executed.

[alan4908]

6 hours ago, aparker said:

Beautiful image.  Love the tight stars and super-crisp detail.  Really well executed.

Thanks - the recent adjustments that I made to my telescope's separation spacing between the FF/FR and CCD seem to have improved the consistency of my star aspect ratios (according to CCDInspector) 

Alan