High up in the northern sky, an ancient star cluster almost twice as old as planet Earth twinkles in the distance with a beckoning glow. Known as Messier 3, or M3, this is one of the most captivating globular star clusters discovered so far.
“Globular clusters are inherently beautiful objects,” states NASA, “but Messier 3 is commonly acknowledged to be one of the most beautiful of them all.”
As The Inquisitr previously reported, globular clusters are spherical bundles of stars closely-knit together by gravity. These star clusters are among the oldest stellar formations in the universe, many of them dating back to just a few hundred million years after the Big Bang.
Formed from the same molecular cloud, the stars within globular clusters are all of roughly the same age but boast different masses. This makes some of them shine brighter than others, in a kaleidoscope of colors and lusters.
Nestled deep within the constellation of Canes Venatici (“The Hunting Dogs”), Messier 3 lies about 33,900 light-years from Earth and is estimated to be 8 billion years old. The globular star cluster is home to a staggering 500,000 stars of incredible variety, all shining in different colors within the confines of this sparkling cosmic bauble.
Famous for being one of the largest and brightest globular star clusters known to date, Messier 3 is even visible from Earth. Stargazers casting their inquisitive eyes upon the northern sky are often able to spot its faint glimmer so long as they grab onto their binoculars. But to truly appreciate the beauty of this magnificent structure, one must venture further into the cosmos and gaze at Messier 3 through the lens of a space telescope.
Luckily, Hubble has been keeping a close eye on the distant globular cluster. The space telescope has recently spied on its flickering stars, capturing their colorful glimmer in a breathtaking photo.
The glorious snapshot was unveiled yesterday by NASA as part of the space agency’s #HubbleFriday segment on Twitter. The image was also published by the European Space Agency (ESA), which operates the Hubble Space Telescope together with NASA.
The stunning Hubble view of Messier 3 gives a very detailed look into the inner workings of this fascinating star cluster. Unlike most similar stellar formations, this particular globular cluster boasts an unusually large population of variable stars — a type of stars of fluctuating brightness, which change in luminosity over time, explains NASA.
“New variable stars continue to be discovered in this sparkling stellar nest to this day, but so far we know of 274, the highest number found in any globular cluster by far.”
More than half of these stars – at least 170, to be exact – belong to a special variety called RR Lyrae variables. What makes these stars unique is the fact that they “pulse with a period directly related to their intrinsic brightness,” notes NASA. This allows astronomers to pinpoint their exact distance from Earth by looking at how bright they appear to be from our terrestrial viewpoint in comparison to their known luminosity, as calculated based on their mass.
“For this reason, RR Lyrae stars are known as standard candles — objects of known luminosity whose distance and position can be used to help us understand more about vast celestial distances and the scale of the cosmos.”
Aside from this particular type of stars, Messier 3 also fosters what scientists refer to as blue stragglers — peculiar stars that stand out from the crowd thanks to their blue, incandescent glow, as seen in the new Hubble photo.
These stars have long puzzled astronomers because they appear to be younger than their same-aged siblings. However, their discordantly youthful appearance is due to a difference in mass rather than in age.
“A red, old star can appear bluer when it acquires more mass, for instance by stripping it from a nearby star. The extra mass changes it into a bluer star, which makes us think it is younger than it really is.”
Renowned for being the first Messier object to be discovered by Charles Messier himself, the Messier 3 globular cluster was first spotted more than two-and-a-half centuries ago, on May 3, 1764. This stellar structure is part of Hubble’s Messier catalog, which brings together some of the most fascinating objects that can be observed from Earth’s Northern Hemisphere.