Hubble views an old and mysterious cluster

Nov 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.

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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: Physicists find black holes in globular star clusters, upsetting 40 years of theory

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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 (1) 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.