Alrighty ... in the spirit of this wonderful image created by Tragoolchitr Jittasaiyapan which feat. the 25 brightest stars in the galaxy, I thought I would add to this gorgeous library by doing something similar ....

The 25 brightest galaxies in Optical light!

#Galaxies https://twitter.com/CosmicRami/status/1139677482536144896

So here is the image I created, and i'll explain / provide credits in the next few tweets in this thread.

(also - forgive my photoshopping skills)

#Galaxies #Astronomy #Space

So firstly, I got the order of the galaxies from the Sky Guide app - which lists galaxies in order of brightness OR alphabetically OR by visibility.

It is a very good app.

#Galaxies

Then I went to the @CSIRO_ATNF Data Portal and used the CASDA Skymap Search. CASDA stands for: CSIRO #ASKAP Data Archive.

It is an excellent free resource and you should all use it: https://data.csiro.au/dap/specificSearch

#Galaxies

Once I was in CASDA, I used the burger menu to change the filter to "DSS Coloured"

This stands for "Digital Sky Survey" and all the images are credit of this survey (I obviously didn't take them - just collated them into one image)

#Galaxies

For identification, I used the Messier catalogue number where possible, then the NGC number. In one case, only the IC number is available.

The order of images should be reviewed like reading a book - start at top line, work left to right, then go to next line etc.

#Galaxies

But there are some galaxies you might notice by other more common names:

1 - LMC
2 - SMC
3 - Andromeda
5 - Centaurus A
10 - Pinwheel
11 - Sombrero
20 - Whirlpool
23 - Fornax A

#Galaxies

Obviously, at this scale some look brighter than the ordering, but that is simply due to the image capture.

Distance, angular diameter, exposure times etc. are not factored for in this ordering. Only their magnitude is.

#Galaxies

What I find really beautiful is all the shapes, colours and orientations (to our view) that these top 25 galaxies come in!

Some have spirals, some have dust rings, some are side-on, others face on - it's literally a galaxy zoo out there!

#Galaxies

BTW - this is something that anyone can do, all you need is a bit if curiosity and be willing to click a few different filters on the @CSIRO_ATNF CASDA portal.
https://data.csiro.au/dap/public/casda/casdaSkymapSearch.zul

Everything you don't understand (like acronyms) just Google them!

#Galaxies

I'll be putting out 5 x galaxies a day threads on Instagram ( @CosmicRami), with a small blurb about each galaxy starting from tomorrow if you want to learn / read more about these beautiful Island Universes!

Hope you like the pic!

/thread

#Galaxies