How can such a mass of inflated hydrogen and helium can be heavier than any 500 kilometer wide, rock solid and compact asteriod? As a comparison, just take a montgolfier full of hot air and compare its weight to that of the earth's atmosphere -- it will fly up in the air and level the individual that holds it by a string. Yet the air in the balloon is not even as light as a mix of hydrogen and helium.
2007-03-12 13:18:59 · 5 answers · asked by Roy Nicolas 5 in Science & Mathematics ➔ Astronomy & Space
1.988 435×10 KG (332,946 Earths)
You've asked about one of the fundamental issues in astronomy, namely determining the mass of objects such as the Sun and other stars. The short answer is that there is no other way to *directly* measure the mass of the Sun or any other star than by observing the gravitational effects of one object on another.
You can estimate the mass of the Sun one of two ways. Both use Newton's Laws of motion. The first way uses Newton's revision of Kepler's third law, which states that the period squared or any body orbiting the Sun is proportional to its average distance from the Sun cubed. Newton generalized this for all gravitating systems.
2007-03-12 17:20:52 · answer #1 · answered by spaceprt 5 · 0⤊ 0⤋
You seem to have mixed up mass, weight and density. You also seem to be mixed up about buoyancy.
A balloon filled with either hydrogen or helium will float. But the reason things float is because they are less dense than the fluid (gas or liquid) that surrounds them.
Imagine pushing a beach ball into a bathtub filled with water. In order to push the beach ball down, the water level must rise. The force you use to push the beach ball down is exactly the force you'd need to use to push that much water up.
Think about it a little and I think you'll see where you are mixed up.
2007-03-12 20:34:32 · answer #2 · answered by 2 meter man 3 · 1⤊ 0⤋
You must understand that the sun is very dense, even though it is a gas. I don't know the figures, but the density of the central parts of the sun is many tons per cubic inch (necessary to support fusion).
As far as WEIGHT goes, the sun, being in free fall (like a satellite of the earth) and despite the almost neglible pulls of the planets, is weightless. It weighs nothing at all! It is however, as others have pointed out, very massive.
2007-03-12 21:27:34 · answer #3 · answered by David A 5 · 0⤊ 0⤋
The weight of an object is defined as the force of gravity on the object and may be calculated as the mass times the acceleration of gravity. In the case of the sun the "acceleration of gravity" acting on it would be the sum of all the objects in the solar system, obviously an extremely complex undertaking to determine. That's why astronomers talk about the mass of the sun, not its weight. Its mass is 2.2^27 tons.
2007-03-12 21:09:54 · answer #4 · answered by Chug-a-Lug 7 · 0⤊ 0⤋
so i guess it's not that heavy after all..
2007-03-12 20:22:15 · answer #5 · answered by Alicia 3 · 0⤊ 0⤋