Globular clusters
What is the difference between the different types of star clusters?
There are three types of star clusters:
globular, open, and associations
. Globular clusters have diameters of 50–450 light-years, contain hundreds of thousands of stars, and are distributed in a halo around the Galaxy. … Associations are found in regions of gas and dust and contain extremely young stars.
What are the main differences between open or galactic star clusters vs globular clusters?
An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud, and are still loosely gravitationally bound to each other. In contrast,
globular clusters are very tightly bound by gravity
.
How are do globular clusters differ from open clusters quizlet?
open clusters contain up to several thousand stars and are found in the disk of the galaxy. Globular clusters contain
thousands of
stars, all closely packed together. They are found mainly in the halo of the galaxy.
What is the difference between an open cluster an association and a globular cluster in which components of the galaxy does each lie?
An open cluster is a
group of up to a few thousand stars
that are roughly the same age and held together by gravitational attraction. … globular clusters contain 100,000 to 1 million tightly packed stars and contain some of the oldest stars.
Why do globular clusters not collapse?
What keeps these clusters from collapsing is
the angular momentum of the stars as they orbit the cluster’s center of mass
. It’s the same physics that keeps the solar system from collapsing.
What are two types of clusters?
The two types are
open (formerly called galactic) clusters and globular clusters
.
What eventually happens to open clusters?
Eventual fate
Many open clusters are
inherently unstable
, with a small enough mass that the escape velocity of the system is lower than the average velocity of the constituent stars. These clusters will rapidly disperse within a few million years.
What do all star clusters have in common?
A star cluster is a group of stars that
share a common origin
and are gravitationally bound for some length of time. They are are particularly useful to astronomers as they provide a way to study and model stellar evolution and ages.
Which of these star clusters is oldest?
A team of astronomers using the Gemini-South telescope has discovered one of the oldest stellar clusters in the Milky Way. The team’s results date the globular cluster, named
HP 1
, at about 12.8 billion years, making its stars among the oldest ever found in our Galaxy.
What does a globular cluster look like?
In a telescope, a globular cluster looks like
a fuzzy ball
, with individual stars at the periphery merging into a solid ball of light towards the center. However, this is simply because the stars are so close together that they can’t be resolved individually telescopically.
Where are globular clusters found?
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 are at least two ways that astronomers can tell how old a globular cluster is?
By placing the stars in a globular cluster on a Hertzprung-Russell diagram, astronomers can determine the cluster’s age by
looking at the main sequence turnoff point and comparing it with models of stellar evolution
. Q: The globular cluster NGC 6397 is 7,800 light-years away.
What if we lived in a globular cluster?
To live on an Earth in a globular cluster would mean that the cluster’s stars (if they were like our Sun)
would combine to create a night sky at around 20 times brighter than Earth’s night sky at full Moon
.
Is the Sun in an open cluster?
Our own Sun was born within such a
cluster 4.6 billion years ago
. Since then, it and its stellar siblings have dispersed throughout the galaxy, but astronomers are keen to hunt those siblings down.
What is an example of an open cluster?
Bottom line: Open clusters are loosely bound gatherings of stars that may be so young that they are still surrounded by the nebulae they were born in.
The Pleiades, Hyades, and Beehive
are well-known examples of open clusters.
