Table of Contents
What is the mass of a galaxy?
around 1.5 trillion solar masses
Their answer: The galaxy weighs around 1.5 trillion solar masses. This number helps put in perspective how very small we are. Take, for instance, where stars in the Milky Way fit in.
What is the mass of a star?
The masses of stars span the range from 0.08 to 150 (or more) times the mass of the Sun.
What are stars and galaxies made of?
Galaxies are composed of stars, dust and dark matter, all held together by gravity. Astronomers aren’t certain exactly how galaxies formed. After the Big Bang, space was made up almost entirely of hydrogen and helium.
What is the composition of the stars?
It was found that the average star’s atmosphere consists mostly of hydrogen (87\%) and helium (10\%), with all other elements making up about 3\%. Helium was actually first discovered in the Sun’s spectrum.
Do galaxies have mass?
They measured the velocities of hundreds of stars in orbit around the galaxies’ centres, which allowed them to calculate the mass of the galaxies’ cores. Surprisingly, the team found that the galaxies all weigh the same – roughly 10 million times the mass of the Sun.
What determines a stars mass?
A star’s mass is determined by the amount of matter that is available in its nebula, the giant cloud of gas and dust from which it was born. Over time, the hydrogen gas in the nebula is pulled together by gravity and it begins to spin. As the gas spins faster, it heats up and becomes as a protostar.
How do you calculate the mass of a star?
Calculating Mass Once all that information is known, astronomers next do some calculations to determine the masses of the stars. They can use the equation Vorbit = SQRT(GM/R) where SQRT is “square root” a, G is gravity, M is mass, and R is the radius of the object.
What are the components of a galaxy?
A spiral galaxy like the Milky Way has three basic components to its visible matter: the disk (containing the spiral arms), the halo, and the nucleus or central bulge. These components are indicated schematically in the following figure.
Which compositions of stars in percentages of mass are possible?
The chemical composition of the Universe is dominated by the hydrogen and helium produced in the Big Bang. The remaining 90 or so chemical elements are produced in stars and constitute only a few percent of the overall mass….
| Chemical composition of the Sun | |
|---|---|
| Oxygen | 0.80\% |
| Carbon | 0.36\% |
| Iron | 0.16\% |
| Neon | 0.12\% |
How do spectral lines tell us the composition of stars?
The science of spectroscopy is quite sophisticated. From spectral lines astronomers can determine not only the element, but the temperature and density of that element in the star. The spectral line also can tell us about any magnetic field of the star. The width of the line can tell us how fast the material is moving.