여성 천문학자들

과학동아 1991년 11호

us, since the variation from point to point is small in comparison with the total distance.She studied the Cepheid variables in the Clouds. These are stars that pulsate. She noted in 1904 that the longer the period of light variation, the greater the average brightness of the star. In 1912, Leavitt had worked out a method for determining the relative distances of various Cepheids.The Cepheids ...

천랑성의 색깔

과학동아 1991년 10호

stars that simply pulsate and that grow larger and dimmer and then grow smaller and brighter. They are called "Cepheid variables." These are particularly important because they can be used to measure the distance of galaxies.Finally, there are stars that are indeed red. In fact, the great majority of stars in the heavens are red. They are small stars and are of dim brightness.They are so small ...

성단(星団)이라는 측정자

과학동아 1988년 05호

years away, for instance, and the Andromeda galaxy is 2,200,000 light-years away. Beyond those 30, though, the Cepheid variables become too dim too see at all, and 30 isn't many. There are billions of galaxies. There are ways of determining the distance of galaxies that are farther off, but they're not as good as the Cepheid method. There are giant stars, for instance, that are much brighter ...