Answer:
The angular diameter in arc seconds is 2.06 * 10^5 arc seconds.
Step-by-step explanation:
To calculate the angular diameter of the neutron star as seen from Earth, we can use the small-angle formula:
Angular Diameter (in radians) = Linear Diameter / Distance
Given the hint that 2.06 * 10^5 arc seconds correspond to the linear diameter-distance ratio, we can set up the equation as:
Angular Diameter (in radians) = (2.06 * 10^5 arc seconds) * (Linear Diameter) / (Linear Diameter)
Since the linear diameter of the neutron star is given as 12 km, we can plug in this value:
Angular Diameter (in radians) = (2.06 * 10^5 arc seconds) * (12 km) / (12 km)
Angular Diameter (in radians) = 2.06 * 10^5 arc seconds
The angular diameter in arc seconds is 2.06 * 10^5 arc seconds.