A ray of light traveling from the sun at about 186,282 miles per second takes about 8 minutes 19 seconds to reach the Earth. Light from those other suns, the stars, takes much longer to reach the Earth. Light from the next nearest star, Alpha Centauri, takes more than four years to arrive, and light from the center of our galaxy, the Milky Way, takes many thousands of years. Because the sun is so near, it seems much larger than the other stars. They are visible on Earth only as bright points, even when viewed with the most powerful telescopes.
Stars vary greatly in size and in color.
They range from giant stars, which are much larger than the sun, to dwarf stars, which can be much smaller than the sun. The telescope has been used in solar studies since 1610. With the telescope, scientists could describe the sun's appearance, watch the movement of sunspots, and measure the sun's rotation. The solar tower telescope, a special vertical telescope, was invented for use in solar studies. The coronagraph, another special telescope, is used to examine the sun's atmosphere.