Want to Explore the Universe From Home? Here’s How

Want to explore the universe from home? here’s how

My favorite part of my job as an astronomer is those rare moments when I can see beautiful distant galaxies, whose light left them millions, even billions of years ago. It’s a combination of sheer wonder and scientific curiosity that excites me about ‘galaxy hunting’.

In astronomy today, much of our job involves managing huge amounts of data by writing and running programs to work with images of the sky. A downside to this is that we don’t always have that “hands-on” experience of looking at every square inch of the universe as we study it. I will show you, however, how I get my dose of wonder from gazing at galaxies that only a select few will have ever seen, until now.

In just our observable universe we estimate that there are more than 2 trillion galaxies!

Galaxies at your fingertips

Only a few decades ago, astronomers had to tediously examine photographic plates after a long, cold and lonely night of observation. In the 21st century, we have access to information anytime, anywhere via the Internet.

Telescopes and automatic soundings now give us so much data that we need machines to help us analyze it. In some cases, human eyes will only look at what computers have found interesting! Massive amounts of data are housed online, just waiting to be admired, for free.

Go online for an atlas of the universe

Aladdin Lite is one of the best online tools available for viewing our universe through the eyes of many different telescopes. Here we can scan the entire sky for hidden galaxies, and even decipher information about their stellar populations and evolution.

Let’s start our Universal Tour by looking for one of the most visually stunning galaxies, the Cartwheel Galaxy. In Aladdin’s interface, you can search for both the popular name of an object (like “cartwheel galaxy”) or known coordinates. The location will be centered in the interface.

The first image of the Cartwheel galaxy that we see comes from optical imagery from the Digitized Sky Survey. The colors we see represent different filters of this telescope. However, these are fairly representative of what the galaxy would look like to our own eyes.

A general rule as an astronomer is that “color” differences within galaxies are due to physically different environments. It’s important to note that things that look blue (shorter wavelengths) are generally hotter than things that look red (longer wavelengths).

In this galaxy, the outer ring appears to be bluer than the red central section. This could allude to star formation and stellar activity occurring in the outer ring, but less in the center.

To confirm our suspicions of star formation, we can choose to look at data from different surveys, in different wavelengths. When young stars form, large amounts of UV radiation are emitted. By changing the survey to GALEXGR6/AIS, we are now only looking at UV wavelengths, and what a difference that makes!

The whole central part of the galaxy seems to “disappear” from our image. This suggests that this section probably harbors older stars, with fewer assets stellar nativity scenes.

Aladdin is home to 20 different investigations. They provide an image of the sky from optical, UV, infrared, X and gamma rays.

When I wander the universe looking for interesting galaxies here, I usually start with optics and find the ones that look interesting to me. I then use the different surveys to see how the images change when looking at specific wavelengths.

Universal Where’s Wally

Now that you’ve had a crash course in galaxy hunting, let the fun begin! You can spend hours exploring the incredible images and finding interesting galaxies. I recommend looking at DECalS/DR3 images for the highest resolution and detail when zoomed in.

The best method is to simply drag the sky atlas. If you find something interesting, you can find all the information we have about it by selecting the target icon and clicking on the object.

To help you on your galactic expedition, here are my favorite finds of the different types of objects you might see.

Spiral galaxies usually have a central rotating disc with large spiral “arms” curving from the denser central regions. They are incredibly beautiful. Our own Milky Way is a spiral galaxy.

Elliptical galaxies are largely featureless and less “flat” than spirals, with the stars sometimes occupying almost a 3D ellipse. These types of galaxies tend to have older stars and less active star forming regions than spiral galaxies.

lenticular galaxies appear like cosmic pancakes, quite flat and featureless in the night sky. These galaxies can be considered as the “in-between” spiral and elliptical galaxies. Most star formation has stopped, but lenticular galaxies can still hold significant amounts of dust.

There are also other amazing types of galaxies, including mergers and lentils, which are waiting for you to find them. I would love to see the amazing things you find on Twitter at @sarawebbscience.


Sara Webbpostdoctoral researcher, Center for Astrophysics and Intensive Computing, Swinburne University of Technology

This article is republished from The conversation under Creative Commons license. Read it original article. This article has been updated since it was first published.

#explore #universe #home #heres

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