Answer:
Of the three stars in the system, the dimmest - called Proxima Centauri - is actually the nearest star to the Sun. The two bright stars, called Alpha Centauri A and B form a close binary system; they are separated by only 23 times the Earth - Sun distance.
Answer: One canister contains 1.03 Kg of fuel,
Explanation:
The density is defined as the relation between the mass and the volume 
First of all you need to have the same units for volume and density, so:
For the volume,

For the density,

From the density equation we have
, so:

The flux will be 4 times stronger ( due to the inverse square law )