At last we will know how bright the stars really are

 作者:覃岿副     |      日期:2019-03-08 02:12:01
By David Shiga LIGHT is the bedrock of astronomy, so it may come as a surprise that astronomers don’t have a very good handle on measurements of brightness. That is set to change, however, as the antiquated brightness scale undergoes a long-overdue upgrade that could help to reveal the true nature of dark energy. More than 2000 years ago, the Greek astronomer Hipparchus devised a scale ranking the apparent brightness of different stars. Today, astronomers use much the same system, measuring brightness relative to a handful of standard reference stars. The trouble is,