[填空题]
Assume that the nearyc(4:0fxn8wg ku7e) mf qskr(eacot9u.f+ zcj8g01n p st stars to us have an absolute luminosity about the same as the Sun's. Their apparent brightness, however, is abo8acz n0+puctjof 1g.9ut $10^{-11}$ times fainter than the Sun. From this, estimate the distance to the nearest stars. (Newton did this calculation, although he made a numerical error of a factor of 100.) ly
