Hubble Variable 1: The Star That Changed the Universe

Today we know that the Universe is filled with billions upon billions of galaxies, but in the early 1900s, it was widely accepted that the Milky Way was a single collection of stars with nothing beyond it. Andromeda, and other galaxies, were believed to just be ‘spiral nebulae’ lying within the Milky Way. However, there were telltale clues that astronomers could use to determine the distance between Andromeda and Earth, one of which is Cepheid variable stars. Stars of this type have very predictable patterns of brightness, which we can derive a light curve from -- thus making variable stars reliable distance markers.

This gave way to the discovery of many of the most fundamental concepts in modern astronomy.

Learn about how one star was able to revolutionize how we saw the universe, at
http://www.fromquarkstoquasars.com/hubble-variable-1-the-star-that-changed-the-universe/

Image Credit: S. Beckwith & the HUDF Working Group (STScI), HST, ESA, NASA

IC 1101 - The Largest Galaxy Ever Found

Galaxies. The Universe is littered with them. They have speckled the vast darkness of intergalactic space with points of light for 13-billion years now, giving birth to numerous twinkly stars and fleeting planets along the way.

Galaxies come in all shapes and sizes. Some are large, some are small, some are inconceivably bright, while others fade into the background.

But one galaxy stands apart from the pack: IC 1101

Find out more about the largest galaxy in the universe, here: http://www.fromquarkstoquasars.com/ic-1101-the-largest-galaxy-ever-found/

Image Credit: NASA

One of the Largest Structures in the Universe:

Astronomers recently discovered a group of active galactic cores that stretch more than 4 billion light-years end to end. The structure is a large quasar group (LQG). And it is simply massive.



For comparison, the Milky Way is about 100,000 light-years across. Our closest neighboring galaxy (Andromeda) is some 2.5 million light-years distant, and it is more than twice the size of the Milky Way (about 260,000 light-years). Which means that this LQG could easily swallow Andromeda, the Milky Way, and all the space in between.

Learn more about this amazing structure and how is impacts the cosmological principle at:
http://www.fromquarkstoquasars.com/largest-structure-in-the-universe-discovered/

Image source:
NARO