PIER-01 Two target suggestions for February sky: UFO Galaxy (NGC 2683) and Lowers Nebula (Sh 2-261)

Hello Martin,

Good idea. These 2 Obkjekte I was also just about to suggest. You have my vote👍🏼

CS

Darius

Please go ahead Martin with those. As far as the emission nebula goes there may be some instances where you could get away with 120 seconds on Ha, but the recommendation is to go for either 240 or 300 seconds, with up to double the number of o3 and s2 subs compared to Ha. I'd probably go for 24 Ha and 40 for o3 and s2. You can always put in a second submission if these turn out to be inadequate. Personally I'd only stick to the maximum of 120 seconds [unguided], with broadband filters. Great M45 image btw. There must have been some serious light gradients but no signs of anything in your image.

Regards,  Ray

Good choice of targets! I am however interested in your thoughts about more data per target. It seems to me that most P1 datasets are short on good quality subs and also on the number of subs. To increase SNR, would it note be adequate to go for a) longer exposures, even if this means guiding and b) more subs?

What are your thoughts?

CS

Manuel

Good choice of targets! I am however interested in your thoughts about more data per target. It seems to me that most P1 datasets are short on good quality subs and also on the number of subs. To increase SNR, would it note be adequate to go for a) longer exposures, even if this means guiding and b) more subs?

 

What are your thoughts?

 

CS

Manuel

Hi Manuel,

excellent question, and I guess there´s no right or wrong answer to it. Image processing skills as well as image quality perception are highly subjective measures ;-)

And yes, SNR increases proportional to rootsquare(integration time), so in order to double the (photon limited) SNR you have to invest 4 times more integration time. So where´s the best point to stop, since integration time is a very valuable and limited ressource?

I now put in requests for almost 9h integration time for the UFO-galaxy (LRGB) and a little more than 6h for the lower nebula (Ha SII OIII).

As Ray mentioned - if the data turns out to be insufficient we can allways request additional data...

CS Martin

Hi Manuel,

excellent question, and I guess there´s no right or wrong answer to it. Image processing skills as well as image quality perception are highly subjective measures ;-)

And yes, SNR increases proportional to rootsquare(integration time), so in order to double the (photon limited) SNR you have to invest 4 times more integration time. So where´s the best point to stop, since integration time is a very valuable and limited ressource?

I now put in requests for almost 9h integration time for the UFO-galaxy (LRGB) and a little more than 6h for the lower nebula (Ha SII OIII).

As Ray mentioned - if the data turns out to be insufficient we can allways request additional data...

CS Martin

 

 

Fair point, we can always request more if needed.  

Cheers

Manuel