Who's good at Science?

Question

1. What the three things that can affect a star's magnitude?
2. Do stars really Twinkles? Why or why not?
3. What is the key word for most of a star's behavior and almost everything that occurs in the Universe? _________

Answer 1

1. Its mass, its age, its energy state

2. The earth's atmosphere makes stars appear to twinkle owing to their vast distances from us. They appear as points of light and so the light rays are bent differently by small ongoing variations in the earths atmosphere and so cause minor movements and fluctuations. However planets are disks rather than points (even though our eyes do not perceive their size). They are large enough to not appear to move like stars do as the position variations caused by bending of light by the atmosphere are 'within' the size of the planetary disk. Also the visible planets are very very bright compared to most visible stars so variations in light intensity are not so obvious.

3. This is a difficult one. For example:

Is it hydrogen, the primordial element of the universe??
Is it energy as energy is what makes it all happen??
Is it gravity as gravity causes clouds of hydrogen to condense into stars??
Is it fusion as without fusion of hydrogen and then other elements nothing works??

No I cannot answer it. I put this one in the "too hard" basket.

Answer 2

1. 3 things? I can think of way more than that! Mass, temperature, radius, composition, distance to Earth, age, dust between us and the star, etc.
2. If you observe a star from above our atmosphere, they do not appear to twinkle.
3. This is a poorly phrased question (worse than the other two, in fact) and subject to opinion, in my opinion. My guess would be gravity, but other legitamate answers could be mass, time, conservation of energy, physics, etc.

Answer 3

1. The magnitude system deals with a star's brightness.
2. check out Cosmic dust
3. ____________
How about you read your textbook or research from sites like this one
http://dmoz.org/Science/Astronomy/Stars/