Are there any neutron stars near enough for astronomers to get a good size-estimate, based on direct observation? I know that there are many theories regarding what happens inside neutron stars, but I want to know if there are any direct observations of nearby neutron stars which give us a clue as to their actual size and density. Other answers have not helped me, because they were based on THEORY, not DIRECT OBSERVATION !!
I think if there is a binary system of stars then the size of neutron stars can be estimated. This method i would call direction estimation because even for most direct observations various theories are always involved.
When the neutron star passes over the burning star its intensity is dimmed. How much it is dimmed depends on the size ratio of visible and neutron star, how long it remain dimmed will depend on the velocity of the neutron star (or star binary) and diameter of the visible star.
The binary star rotates about its center of mass with some speed and that can be estimated from Doppler shift.
Combining these factors can give you the size of neutron star.
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