The M55 globular star cluster is a fascinating astronomical object located in the constellation Sagittarius, about 17,600 light-years away from Earth. It was discovered by the French astronomer Nicolas Louis de Lacaille in 1752 and is one of the largest and brightest globular clusters in our Milky Way galaxy.
M55 is estimated to contain hundreds of thousands of stars, tightly bound together by gravity. The stars in the cluster are relatively old, with an age estimated to be around 13 billion years. They are also relatively metal-poor, which is typical of globular clusters, as they are thought to have formed early in the history of the universe.
Hubble sheds light on M55
The good old Hubble Space Telescope, which is owned by NASA, has done it again! A fresh new photo coming from the telescope has been published, and it shows the M55 globular star cluster in all its glory.
This newly released Hubble image shows M55 – a loosely concentrated globular star cluster about 20,000 light-years away.
Only a portion of M55 is seen here, but the whole cluster stretches about 100 light-years in diameter! Read more: https://t.co/Pl9JmN0F16 pic.twitter.com/wAqZS6dZQc
— Hubble (@NASAHubble) March 17, 2023
But don’t let that distance fool you, because the M55 cluster is actually pretty popular in the astronomy world. It’s a bit like the cool kid’s party that everyone wants to go to. The cluster has been studied extensively by astronomers because it’s a great example of a globular star cluster, which is like a fancy way of saying it’s a bunch of stars that are all besties with each other.
What makes the M55 cluster even more interesting is that it’s home to a bunch of variable stars, which are basically stars that like to change things up every now and then, just to keep everyone on their toes. Some of these stars pulsate, while others like to randomly brighten or dim. It’s like they’re trying to play a cosmic game of hide and seek.
One amazing fact about the Hubble Space Telescope is that it has traveled over 5 billion kilometers since its launch in 1990. Despite being in low Earth orbit, Hubble has traveled a distance that’s roughly equivalent to going to Pluto and back again! This is because the telescope orbits the Earth at an altitude of about 550 kilometers, completing a full orbit every 97 minutes.
