[OU.03] What is the best method to increase the accuracy of the parallax measurement of star distances?

Trigonometric or Stellar Parallax

Explanation:

Whenever a star is too far away to measure its parallax, astronomers do match its color and spectrum to one of the standard candles and determine its intrinsic brightness.

Comparing this to its apparent brightness, they can get a good measure of its distance by applying the 1/r^2 rule.

Astronomers estimate the distance  of nearby objects in space by using a method called stellar parallax, or trigonometric parallax. They measure a star's apparent movement against the background of more distant stars as Earth revolves around the sun.

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.