0.01 arcsecond (0.01″) is a very small unit of angular measurement, equal to one hundredth of an arcsecond. It is often used in astronomy to measure the size and positions of celestial objects, such as stars, planets, and galaxies.

To put 0.01 arcseconds in perspective, consider the following:

- The full moon has an angular diameter of about 31 arcminutes, or 1860 arcseconds. This means that 0.01 arcseconds is about 0.0005% the size of the full moon.

- The human eye can resolve objects that are separated by about 1 arcminute, or 60 arcseconds. This means that 0.01 arcseconds is about 0.02% of the smallest angle that the human eye can see.

- The Hubble Space Telescope can resolve objects that are separated by about 0.05 arcseconds. This means that 0.01 arcseconds is about 20% of the smallest angle that the Hubble Space Telescope can see.

In summary, 0.01 arcseconds is an extremely small unit of angular measurement, used in astronomy to measure the size and positions of celestial objects.