Table of Contents
What keeps a star in place?
The stars in our galaxy are all orbiting in a nearly circular path around the center of the galaxy. They do this because the immense combined mass of the galaxy, most if it near the center, creates immense gravity that pulls all the stars in our galaxy into circular orbits.
What 2 Forces holds a star together?
Gravitational forces act to contract the star. Fusion reactions and heat convection act to expand the star. The two forces are balanced and the star remains stable in size and reactions.
What keeps a star from collapsing?
Stars are fueled by the nuclear fusion of hydrogen to form helium deep in their interiors. The outflow of energy from the central regions of the star provides the pressure necessary to keep the star from collapsing under its own weight, and the energy by which it shines.
Why do the stars stay in the same place?
The stars in a constellation appear to be in the same plane because we are viewing them from very, very, far away. Stars vary greatly in size, distance from Earth, and temperature. Dimmer stars may be smaller, farther away, or cooler than brighter stars.
How do stars move?
These apparent star tracks are in fact not due to the stars moving, but to the rotational motion of the Earth. As the Earth rotates with an axis that is pointed in the direction of the North Star, stars appear to move from east to west in the sky.
What makes a star a sun?
Sun
| False-color image taken in 2010 as seen in ultraviolet light (wavelength of 30.4 nm) | |
| Names | Sun, Sol /ˈsɒl/, Sól, Helios /ˈhiːliəs/ |
| Adjectives | Solar /ˈsoʊlər/ |
| Observation data | |
|---|---|
| Mean distance from Earth | 1 AU ≈ 1.496×108 km 8 min 19 s at light speed |
What forces affect a star?
Pressure and gravity. Pressure due to fusion reactions pushes outwards. Gravity pulls inwards to keep the star in equilibrium.
What two forces keep a star from collapsing or exploding?
While self-gravity pulls the star inward and tries to make it collapse, thermal pressure (heat created by fusion) pushes outward. These two forces cancel each other out in a main sequence star, thus making it stable.
What happens inside a star?
Stars are mainly made of hydrogen and helium gas. In the centre of a star, the temperature and pressure are so high that four protons can fuse to form helium, in a series of steps. This process releases huge amounts of energy and makes the stars shine brightly. At the beginning of their life, stars burn hydrogen.
How fast do stars move?
The speed a star moves is typically about 0.1 arc second per year. This is almost imperceptible, but over the course of 2000 years, for example, a typical star would have moved across the sky by about half a degree, or the width of the Moon in the sky.