Obviously they can't give you an exact weight, but with aid of many different cameras on space based and Earth based telescopes, including standard light, infrared, and many other types scientists can quite easily closely estimate the weight of stars and their make up of elements. If
you have the knowledge and know how with mathematics you can get a good estimate on these things. For instance, different gases have different weights and give off different colors of light and different spectral lines, and while these gases are squeazed down so tight in the gravity of pulsar. It gives them a good idea how much that star weighs. Also the reason this star is called a pulsar, is because it sends out a strong concentrated beam of radio waves out of both of its poles. The pulsar has a regular rate of spin as fast as even 100 times per second. The
poles swing toward Earth and satellites and radio telescopes pick of these waves as pulses just like
you'd see from rotating search light or the light from a lighthouse.

My comment was about the same as the previous one. Since no scientist has had the opportuinty to actually have one how can they possibly know what it's weight would be. Next week they will claim it's as light as a feather. All their presumptions make people crazy.They should stick to the hard facts before they announce their findings

How the %^&& do they know this??? Who has been there to weigh them???? It is purely presumptious!!