What defines a globular cluster?
globular cluster, a large group of old stars that are closely packed in a symmetrical, somewhat spherical form. Globular clusters, so called because of their roughly spherical appearance, are the largest and most massive star clusters.
What best describes a globular star cluster?
Which of the following statements best describes globular clusters? They contain from hundreds of thousands to millions of stars and have a typical size of about 50 parsecs.
What is the difference between globular and open clusters?
Globular clusters are old clusters of stars that have remained in a gravitationally bound system. Open clusters are much younger and smaller than globular clusters. They are the recent birthplaces of new stars, which form out of clouds of dust and gas, and contain only hundreds or thousands of stars.
What are the characteristics of globular cluster stars?
Globular star cluster are very symmetrical in shape, and are densest toward their centers. Open star clusters are more irregular in shape. Globular clusters orbit in the halo of our galaxy, centered on the galaxy’s center and expanding above and below the galactic disk. Open star clusters tend to orbit within the disk.
Where are globular clusters found?
the Milky Way
Globular star clusters are known to be located mostly in the great spherical halo of the Milky Way. Spiral galaxies like our Milky Way contain stars, gas and dust, mostly organized into a flat disk containing the spiral arms, but with the addition of a more rounded bulge and halo, centered on the galaxy’s center.
What do you mean by globular?
Definition of globular 1a(1) : having the shape of a globe or globule. (2) : composed of compactly folded polypeptide chains arranged in a spherical form globular proteins. b : global. 2 : having or consisting of globules.
How does a globular cluster form?
Physics. Globular clusters formed from giant molecular clouds, or huge masses of gas that form stars as they collapse. Each globular cluster moves as a whole in its host galaxy, but within the cluster the stars also move individually and randomly – almost like molecules in a gas, Richer said.
How do stars orbit in a globular cluster?
The stars that compose globular clusters and many open clusters all orbit the cluster center, occasionally interacting, gravitationally, with a close-passing star. The orbits of stars around the cluster are typically not as circular as the orbits of planets in our solar system.
How do globular clusters form?
Is a globular cluster bigger than a galaxy cluster?
When comparing the two, a typical globular cluster might contain a mass of 100,000 Suns, whereas the Milky Way has nearly 1 trillion solar masses. In other words, the Milky Way Galaxy contains 10 million times more mass than a typical globular cluster.
What types of stars are in globular clusters?
Globular clusters are generally composed of hundreds of thousands of low-metal, old stars. The stars found in a globular cluster are similar to those in the bulge of a spiral galaxy but confined to a spheroid in which half the light is emitted within a radius of only a few to a few tens of parsecs.
Is a globular cluster bigger than a galaxy?
How are globular star clusters different from open star clusters?
Here are some ways that globular star clusters and open star clusters are different: Globular star cluster are very symmetrical in shape, and are densest toward their centers. Open star clusters are more irregular in shape.
What does the structure in the H-R diagram indicate?
This structure in the H-R diagram indicates a common set of physical processes apply to stars in particular regions of the diagram. Most stars (90%) in the local neighbourhood lie on a sequence from hot, luminous stars to cool, dim ones – the Main Sequence (MS).
What causes stars to move up and down the H-R diagram?
The star thus moves up and to the right on the H-R diagram, climbing the Red Giant Branch (RGB). Helium Flash – At the tip of the RGB the helium rich core ignites and helium fusion begins. This ignition of the core causes the star to move rapidly down the H-R diagram to the Horizontal Branch region.
How do astronomers determine the age of stars in a cluster?
In particular, by plotting a HR diagram for either a globular or open cluster of stars, astronomers can estimate the age of the cluster from where stars appear to turnoff the main sequence (see the entry on main sequence for how this works).