Multiple One-click Observations Question

[Todd Tucker]

I see where there were several recent sessions for NGC253.  I grabbed the first one and processed it (one hour).  In theory, could I grab the other two sessions and now have 3 hours of data vs the one?  It was taken with the same telescope and filters.  Can I also assume the framing is the same for all three?  Thanks

[ERNESTO GUIDO]

Hello Todd, thanks for your message. 

Yes, that is correct. We image the same target many times with the same telescope (and with same framing) so to have more SNR. The single dataset is OK to produce a nice colour image, but of course more data is better.

 

Clear Skies,

Ernesto

[Todd Tucker]

Thanks!!!!!

[Astro Newbie]

Hi Todd,  

A way to confirm that newly acquired data can be combined, either across a recent short period of time but sometimes and unknown to you from a much earlier time, is to use 'Observation bundles'. As Ernesto said, images are captured using the same coordinates to allow combining of datasets to improve SNR.

In the case of NGC253 (Sculptor galaxy) using Observation bundles you will see that there are in fact 12 datasets available where the CHI-1-CMOS setup was used, totalling 15 hours! I don't know if you have a certain level of membership, but as a Gold member I can get a nice discount on the bundle. You'll note that other bundles using other setups are also shown, but as separate ones will not match any of the others. There have to be at least 5 ungrabbed datasets left to get a discount. 

When viewing 'All observations' typing in the Object name will display all the datasets,and typing in the Telescope name will show just those ones. Any you have already grabbed will be shown as grabbed. Without receiving any discount, you can select any number of the ungrabbed ones and have them downloaded in one set. 

If I have anything wrong perhaps someone will post a correction. 

Cheers and CS,

Ray (Still learning more about Telescope live myself)