Its a combination of pure awe and scientific curiosity that excites me about galaxy hunting.
In just ourobservable universewe estimate there are over 2 trillion galaxies!
In the 21st century we have access to information any time, anywhere via the internet.
It’s free, every week, in your inbox.
Automatic telescopes and surveys now provide us with so much data we require machines to help us analyze it.
In some cases human eyes will only ever look at what the computers have deemed is interesting!
Massive amounts of data are hosted online, just waiting to be admired, for free.
The location will be centered in the interface.
The first image of the Cartwheel Galaxy we see is from optical imaging by the Digitized Sky Survey.
The colors we see represent different filters from this telescope.
However, these are fairly representative of what the galaxy would look like with our own eyes.
In this galaxy, the outer ring seems to be more blue then the center red section.
When young stars are forming, vast amounts of UV radiation are emitted.
Online view in Aladin Lite of the Cartwheel Galaxy in GALEX UV wavelengths.
The whole center section of the galaxy seems to disappear from our image.
This suggests that section is likely home to older stars, with less activestellar nurseries.
Aladin is home to 20 different surveys.
They provide imaging of the sky from optical, UV, infrared, X and gamma rays.
I then use the different surveys to see how the images change when looking at specific wavelengths.
UniversalWheres Wally
Now youve had a crash course in galaxy hunting, let the game begin!
you’ve got the option to spend hours exploring the incredible images and finding interesting-looking galaxies.
I recommend looking at images from DECalS/DR3 for the highest resolution and detail when zooming further in.
The best method is to just drag the sky atlas around.
Examples of spiral galaxies found using Aladin online.
Spiral galaxiestypically have a central rotating disc with large spiral arms curving out from the denser central regions.
They are incredibly beautiful.
Our own Milky Way is a spiral galaxy.
Examples of elliptical galaxies.
This key in of galaxy has an approximately ellipsoidal shape and a smooth, nearly featureless image.
Elliptical galaxiesare largely featureless and less flat then spirals, with stars occupying almost a 3D ellipse at times.
These throw in of galaxies tend to have older stars and less active star-forming regions compared to spiral galaxies.
Examples of lenticular galaxies.
These are a throw in of galaxy intermediate between elliptical and a spiral galaxies.
Lenticular galaxiesappear like cosmic pancakes, fairly flat and featureless in the night sky.
These galaxies can be thought of as the in between of spiral and elliptical galaxies.
The majority of star formation has stopped but lenticular galaxies can still have significant amounts of dust in them.
Id love to see what amazing things you find over on Twitter at@sarawebbscience.
you might read other articles in this serieshere.
