What is the angulat diameter of a star like the sun located 5 light years from Earth?

Is the Hubble Space telescope able to detect detail on the surface of such a star?What is the angulat diameter of a star like the sun located 5 light years from Earth?5 light years is about 315,360 times as far as 93 million miles, so that star would have an angular diameter 315,360 times smaller than the Sun does for us. We see the sun subtending half a degree, or 30 arc minutes or 1,800 arc seconds. So 1,800 / 315,360 = 0.0057 arc seconds. The highest resolution instrument currently on HST is the Advanced Camera for Surveys at 0.03 arc second. And Dawes' limit says the smallest detail the Hubble's 94 inch mirror can resolve is 0.048 arc seconds, so the camera is actually not the limiting factor. So a Sun like star 5 light years away would be at least 5 times smaller than the smallest detail Hubble can see.What is the angulat diameter of a star like the sun located 5 light years from Earth?Sun is 499 light seconds away and it creats an arc of 31.6 mins.



this means that the radius of the sun is about 499*tan(0deg 15.8 min) (expressed in light seconds)

If the sun is 5 light years away, and the angular diameter isT



499 tan (0deg 15.8 min)/5*365*24*3600 = tan(T/2)

2.283/(5*365*24*3600) = tan(T/2)

T = 1.17154E-06 (degrees)

= 0.004235 seconds of arc.



So its about 445763 times smaller than the arc that sun creates.



According to my source (i've specified it below), the angular resolution of the hubble telescope is 0.085 arc seconds. So its about 20 times smaller (in the angular diameter) than the resolution of the telescope.