How would you expect a star that formed recently in the disk of the galaxy to differ from one that formed early in the history of the disk? It should have a higher fraction of elements heavier than hydrogen and helium.
Besides, Why are stars no longer forming in the galactic halo?
Why has star formation ceased in the galactic halo? All of the galaxy’s cool gas settled to the galactic plane long ago. How do we learn about the conditions at the center of our own galaxy, the Milky Way? detected and used to determine the conditions there.
Keeping this in mind, How should we expect that the interstellar medium of the Milky Way will be different in 50 billion years? How should we expect the Milky Way’s interstellar medium to be different in 50 billion years than it is today? The total amount of gas will be much less than it is today. … Suppose you want to observe and study the radiation from gas inside an interstellar bubble created by a supernova.
How do we know that spheroidal stars are older on average than disk stars?
How do we know that spheroidal stars are older, on average, than disk stars? There are no blue spheroidal stars. … Halo stars differ in age and heavy-element content, but these variations do not seem to depend on the stars’ distance from the galactic center.
Where in the galaxy would you expect ongoing star formation?
Spiral galaxies are named by their spiral structures that extend from the center into the galactic disc. The spiral arms are sites of ongoing star formation and are brighter than the surrounding disc because of the young, hot OB stars that inhabit them.
Are stars formed in the halo?
The halo contains very old stars and globular clusters. … Stars form inside relatively dense concentrations of interstellar gas and dust known as molecular clouds.
Why are we unlikely to find Earthlike planets around halo stars in the galaxy?
Why are we unlikely to find Earth-like planets around halo stars in the Galaxy? A) Planets around stars are known to be extremely rare. … Halo stars formed in an environment where there were few heavy elements to create rocky planets. C) Any such planets would have been ejected long ago by galactic mergers.
How were halo stars formed?
Clues come from the Milky Way’s oldest and wisest stars—those in the stellar halo, the galactic component that envelops the bright disk housing the sun. Halo stars stand out because they formed before supernova explosions had scattered a large amount of heavy elements into the galaxy, so halo stars possess little iron.
How does the interstellar medium affect our view of the most of the galaxy?
How does the interstellar medium affect our view of most of the galaxy? It prevents us from seeing most of the galactic disk with visible and ultraviolet light.
What effect does the interstellar medium have on our view of most of the galaxy?
How does the interstellar medium obscure our view of most of the galaxy? It produces so much visible light that it is opaque and blocks our view of anything beyond it. It reflects most light from far distances of the galaxy away from our line of sight. It absorbs visible, ultraviolet, and some infrared light.
How does a lenticular galaxy differ from a normal spiral galaxy?
Lenticular galaxies are sometimes called “armless spiral galaxies.” Lenticular galaxies have a central bulge, but no spiral arms. If the central bulge is not very bright, it can be very difficult to tell the difference between a lenticular galaxy and an E0 galaxy.
How do halo stars differ from disk stars?
Disk stars come in a broad range of masses and colors, while halo stars are mostly of low mass and red. Clusters of young stars are found only in the disk. Stars in the disk all orbit in the same direction and nearly the same plane, while halo stars have more randomly oriented orbits.
What is the evidence that indicates to some astronomers that a supermassive black hole exists at the center of our galaxy?
Direct evidence for a supermassive black hole – a plot of the orbital motion of the star S2 around the centre of the Milky Way. From these observations, astronomers have inferred that a supermassive black hole of about 3 million solar masses lurks at the centre of our galaxy.
What evidence suggests that most of the mass of the Milky Way is in the form of dark matter?
What evidence suggests that most of the mass of the Milky Way is in the form of dark matter? The orbital speeds of stars far from the galactic center are surprisingly high.
Where does most star formation take place in the Milky Way?
Star formation occurs most rapidly in the spiral arms, where the density of interstellar matter is highest. The Galaxy captured (and still is capturing) additional stars and globular clusters from small galaxies that ventured too close to the Milky Way.
Where do stars form?
Star Formation
Stars are born within the clouds of dust and scattered throughout most galaxies. A familiar example of such as a dust cloud is the Orion Nebula. Turbulence deep within these clouds gives rise to knots with sufficient mass that the gas and dust can begin to collapse under its own gravitational attraction.
Which part of a spiral galaxy is most likely to be forming stars?
The arms of a spiral galaxy have lots of gas and dust, and they are often areas where new stars are constantly forming. The bulge of a spiral galaxy is composed primarily of old, red stars. Very little star formation goes on in the bulge.
What are halo stars?
A stellar halo is an essentially spherical population of stars and globular clusters thought to surround most disk galaxies and the cD class of elliptical galaxies. … These ages are similar to those of bulge and globular cluster stars, meaning that stars in the halo were probably among the first Galactic objects to form.
What type of stars are in the halo?
The Milky Way’s stellar halo contains globular clusters, RR Lyrae stars with low metal content, and subdwarfs. Stars in our stellar halo tend to be old (most are greater than 12 billion years old) and metal-poor, but there are also halo star clusters with observed metal content similar to disk stars.
What do halo stars do differently from disk stars?
What do halo stars do differently from disk stars? They orbit the galactic center with many different inclinations, while disk stars all orbit in nearly the same plane. … They have vertical motions out of the plane, making them appear to bob up and down, but they never get “too far” from the disk.
Why do we believe 90 percent of the mass of the Milky Way is in the form of dark matter?
Why do we believe 90 percent of the mass of the Milky Way is in the form of dark matter? the orbital speeds of stars far from the galactic center are surprisingly high, suggesting that these stars are feeling gravitational effects from unseen matter in the halo. What does the universe look like on very large scales?
What objects lie in the halo of our galaxy?
The Milky Way’s stellar halo contains globular clusters, RR Lyrae stars with low metal content, and subdwarfs. Stars in our stellar halo tend to be old (most are greater than 12 billion years old) and metal-poor, but there are also halo star clusters with observed metal content similar to disk stars.
Where are halo stars formed?
Formation of galactic halos
The formation of stellar halos occurs naturally in a cold dark matter model of the universe in which the evolution of systems such as halos occurs from the bottom-up, meaning the large scale structure of galaxies is formed starting with small objects.
Why are stars in the halo old?
These ages are similar to those of bulge and globular cluster stars, meaning that stars in the halo were probably among the first Galactic objects to form. Due to its old age, understanding the processes which led to the formation of the stellar halo is key in unravelling the evolutionary history of the Milky Way.
What are halo stars?
A stellar halo is an essentially spherical population of stars and globular clusters thought to surround most disk galaxies and the cD class of elliptical galaxies. … The halo stars in the Milky Way are generally old, with most having ages greater than 12 billion years.