Hubble views an old and mysterious cluster

November 14, 2013
This cluster of stars is known as Messier 15, and is located some 35 000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters known, with an age of around 12 billion years. Both very hot blue stars and cooler golden stars can be seen swarming together in the image, becoming more concentrated towards the cluster's bright centre. Messier 15 is one of the densest globular clusters known, with most of its mass concentrated at its core. As well as stars, Messier 15 was the first cluster known to host a planetary nebula, and it has been found to have a rare type of black hole at its centre. This new image is made up of observations from Hubble's Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared, and optical parts of the spectrum. Credit: NASA, ESA

The NASA/ESA Hubble Space Telescope has captured the best ever image of the globular cluster Messier 15, a gathering of very old stars that orbits the centre of the Milky Way. This glittering cluster contains over 100 000 stars, and could also hide a rare type of black hole at its centre.

This multi-coloured firework display is a cluster of stars known as Messier 15, located some 35 000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters known, with an age of around 12 billion years.

Very hot blue stars and cooler golden stars are seen swarming together in this image, becoming more concentrated towards the cluster's bright centre. Messier 15 is one of the densest known, with most of its mass concentrated at its core.

However, this sparkling bauble has hidden secrets. Astronomers studying the cluster with Hubble in 2002 found there to be something dark and mysterious lurking at its heart. It could either be a collection of dark neutron stars, or an intermediate-mass black hole. Of the two possibilities it is more likely that Messier 15 harbours a black hole at its centre, as does the massive globular cluster Mayall II.

Intermediate-mass black holes are thought to form either from the merging of several smaller, stellar-mass black holes, or as a result of a collision between massive in dense clusters. A third possibility is that they were formed during the Big Bang. In terms of mass they lie between the more commonly found stellar-mass and supermassive types of black hole, and could tell us about how grow and evolve within clusters like Messier 15, and within galaxies.

This video is not supported by your browser at this time.
This is an animation of a rare and exotic intermediate-mass black hole at the centre of a star cluster, similar to the one thought to be at the centre of globular cluster Messier 15. Studying these unusual black holes could tell us about how such objects grow and evolve within both star clusters and galaxies. Credit: NASA, ESA, and M. Kornmesser

As well as this black hole, Messier 15 is known to house a planetary nebula, Pease 1—and it was the first globular known to contain one of these objects. This nebula is visible as the bright blue object just to the left of the 's centre.

This new image is made up of observations from Hubble's Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared and optical parts of the spectrum.

Explore further: Glittering jewels of Messier 9

Related Stories

Glittering jewels of Messier 9

March 16, 2012

(PhysOrg.com) -- The NASA/ESA Hubble Space Telescope has produced the most detailed image so far of Messier 9, a globular star cluster located close to the center of the galaxy. This ball of stars is too faint to see with ...

Hubble sees Messier 70: Tight and bright

April 13, 2012

(Phys.org) -- In this image, the NASA/ESA Hubble Space Telescope has captured the brilliance of the compact center of Messier 70, a globular cluster. Quarters are always tight in globular clusters, where the mutual hold of ...

Hubble captures a collection of ancient stars

August 27, 2012

(Phys.org)—The NASA/ESA Hubble Space Telescope has produced this beautiful image of the globular cluster Messier 56 (also known as M 56 or NGC 6779), which is located about 33,000 light years away from the Earth in the ...

Runaway binary stars

October 7, 2013

CfA astronomers made a remarkable and fortuitous discovery in 2005: an extremely fast moving star, clocked going over three million kilometers an hour. It appears to have been ejected from the vicinity of the galactic center's ...

Recommended for you

'Bathtub rings' suggest Titan's dynamic seas

July 28, 2015

Saturn's moon, Titan, is the only object in the Solar System other than Earth known to have liquid on its surface. While most of the lakes are found around the poles, the dry regions near the equator contain signs of evaporated ...

Born-again planetary nebula

July 28, 2015

Beneath the vivid hues of this eye-shaped cloud, named Abell 78, a tale of stellar life and death is unfolding. At the centre of the nebula, a dying star – not unlike our Sun – which shed its outer layers on its way to ...

5 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Tuxford
1 / 5 (16) Nov 14, 2013
Ah, and the merger mania continues in the fanciful minds of modern astronomers….who just love mysteries. No mention of the old mixed with the new near the core of the very old structure?

No mystery if examined with LaViolette's model. If the shoe fits….

My early explanation here (of the old and new in harmony):

http://phys.org/n...ter.html

Or maybe you prefer an Agatha Christie tale?

Fleetfoot
5 / 5 (4) Nov 16, 2013
No mention of the old mixed with the new near the core of the very old structure?


That's because there are no new stars observed. The blue ones are "blue stragglers", merged old stars. They are blue because they are hot due to their higher mass but their chemistry confirms they are generally the same age as the rest of the stars in the host cluster.
Fleetfoot
4.2 / 5 (5) Nov 17, 2013
In dense aether model the galaxies are condensing and evaporating from dark matter like the giant density fluctuations of dense gas. And the black holes formed during it are condensing and evaporating too. It means that the Messier 15 can be a remnant of ancient galaxy with its central black hole nearly evaporated.


Complete garbage, there is no such thing as "AWT" but if you want to post about ancient aether theories, at least find out what they would actually have predicted instead of just spouting the first clueless drivel that appears in your mind.
cantdrive85
1 / 5 (11) Nov 17, 2013
No mention of the old mixed with the new near the core of the very old structure?


That's because there are no new stars observed. The blue ones are "blue stragglers", merged old stars. They are blue because they are hot due to their higher mass but their chemistry confirms they are generally the same age as the rest of the stars in the host cluster.

Ah yes, the typical ad hoc explanation of an anomaly that doesn't match the theory. This is the M.O. of the "standard" theorist.
Fleetfoot
5 / 5 (2) Nov 20, 2013
The blue ones are "blue stragglers", merged old stars. They are blue because they are hot due to their higher mass but their chemistry confirms they are generally the same age as the rest of the stars in the host cluster.

Ah yes, the typical ad hoc explanation of an anomaly that doesn't match the theory. This is the M.O. of the "standard" theorist.


Nothing "ad hoc" about it, you just check the spectrum and measure the abundances. As stars age, they build up heavier elements.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.