Globular Star Cluster Tucanae 47 In Great Detail

There are over 150 globular clusters in the Milky way galaxy. The most massive globular star cluster is Omega Centauri. The second most massive is 47 Tucanae.

Star clusters are a group of stars that are held together by their own gravity. Because of their strong gravitational attraction, they form a spherical shape. These spheres contains millions of stars and they get more densely packed as one gets nearer its center.

Inside 47 Tucanae are 23 known millisecond pulsars that are highly magnetized, rotating stellar remnants that emit bursts of radiation as they spin. 47 Tucanae has the most number of these pulsars in observed globular clusters. Pulsars are short for "pulsating stars". These are neutron stars that were formed when a star explodes into a super nova.

Stars in Star Clusters Observed To Age At Varying Rates

Astronomers at the ESO, ESA, and NASA have observed that some stars in star clusters appear young looking than other stars. This is despite the fact that most of the stars in a cluster were formed at the same time and are roughly the same age. This observation was arrived at upon studying bright blue stars called blue stragglers which appear younger than other stars in the cluster.

Star clusters, as the name suggests, are groups of stars that are grouped together. These stars are bound together by their respective gravitational fields.

There are two kinds of clusters; open star clusters and globular star clusters. Open star clusters are a loosely group of hundreds of young stars. Their gravitational attraction is not strong enough to form a tight bond.

A globular star cluster is made up of hundreds and thousands of very old stars whose gravitational attraction to each other is strong enough that they form a very tight spherical shape. As one goes closer to the center, the number of stars get denser.

These clusters orbit a galaxy or the galactic core as one unit much like a satellite would.

The Milky Way galaxy is known to host around 150 star clusters but many more are believed to be undiscovered. The closest galaxy to the Milky Way, the Andromeda galaxy, has 500 clusters while Galaxy M87 has 13,000 globular clusters.

The image above shows the globular cluster NGC 6388 observed by the European Southern Observatory.

Globular Star Cluster NGC 6362 Shown To Have Young Stars As Well As Ancient Ones

The European Southern Observatory's Wide Field Imager telescope at the La Silla Observatory in Chile captures an amazing detailed image of the globular star cluster NGC 6362 showing stars both ancient and young within the cluster.

There are groups of stars bound together by gravity called globular star clusters. Because of the pull of gravity on each other, these globular clusters form tightly bound spheres with high densities of stars going towards the center of it.

A globular star cluster can contain thousands of stars and have been existing longer than some lesser dense galaxies in the universe. In the Milky Way alone, there are around 160 identified globular star clusters with more waiting to be discovered. The Andromeda galaxy is known to have 500 while galaxy M87 has 13,000 globular clusters.

VISTA Telescope Captures Globular Cluster Messier 55 In Rich Detail

A new image of Messier 55 from ESO's VISTA infrared survey telescope shows tens of thousands of stars crowded together like a swarm of bees. Besides being packed into a relatively small space, these stars are also among the oldest in the Universe. Astronomers study Messier 55 and other ancient objects like it, called globular clusters, to learn how galaxies evolve and stars age.

A Globular Cluster is a collection of stars that are shaped into a sphere. They are bound by gravity so tight that they form a sphere. These clusters orbit a galactic core as a satellite and have high stellar densities going toward the center of the sphere.

Globular clusters are found in the halo of a galaxy and has more stars and are older than less dense galaxies and open clusters that are found in the disk. In the Milky Way, there are 160 known globular clusters with more likely to be discovered. Other bigger galaxies, like Andromeda, has 500 while M87 has 13,000 globular clusters.

The first globular cluster discovered was M22 in the constellation Sagittarius by Abraham Ihle in 1665.

VISTA views a vast ball of stars

Globular clusters are held together in a tight spherical shape by gravity. In Messier 55, the stars certainly do keep close company: approximately one hundred thousand stars are packed within a sphere with a diameter of only about 25 times the distance between the Sun and the nearest star system, Alpha Centauri.

About 160 globular clusters have been spotted encircling our galaxy, the Milky Way, mostly toward its bulging centre. The two latest discoveries, made using VISTA, were recently announced. The largest galaxies can have thousands of these rich collections of stars in orbit around them.