If you have ever used a star map or application, you would have seen many many objects listed as "NGC(some number)" . But what does that mean?
NGC is short for New General Catalogue - or, more properly, "The New General Catalogue of Nebulae and Clusters of Stars". It is a catalogue compiled by John Dreyer in 1888 (yes, "new" is relative), and contains about 7800 objects.
You may have also encountered objects listed with an "IC" prefix. These are also part of the New General Catalogue - or more precisely the follow-up supplements called "Index Catalogues" - adding another 5400 objects.
The NGC (and ICs) are sufficienty important that they have been updated, most recently in 2019, and it now contains nearly 14000 objects.
Last night, I imaged one of the IC objects - the Rho Ophiuchi cloud complex, centering on IC4604.
This is an amazing and beautiful nebula complex, but it took some post processing to really bring it to life.
I thought I'd do something a little different with the #Moon tonight.
This is a composite of composites. The pinkish tones come from the second shot with the #DwarfII 's #InfraRed filter removed.
So what we have is:
1/160s50@gain 30 with the IR filter active
and
1/320s50@gain 0 with the IR filter removed.
I then stacked the two stacked images in #snapseed in "overlay" mode, and tweeked the opacity.
The result shows regions with differing IR and Visible light reflectivity, indicating differing compositions.
This evening I got out my little 70mm backpack refractor, and tried to get the #digiscope adaptor working with my mobile. And I got it all aligned! My attempts at Jupiter were not so memorable, but I am really happy with my #moon shot.
20mm eye piece, Saxon Traveller 70mm refractor. #Pixel6a in Night Vison mode. Post processed in #snapseed . #astronomy#astrophotography