noao1201 — Science Release
NOAO: The Lives of Stars, or Astronomers as Paparazzi
16 April 2012: Stars live for a long time, with even the most massive stars having lifetimes measured in millions of years. But, for a mere few thousand years towards the end of their lives, some massive stars go through what astronomers call the yellow supergiant phase. This is remarkably short in astronomical terms, and, as a result, stars in this phase are incredibly rare. In a recent study, astronomers from Lowell Observatory have acted as “stellar paparazzi”, managing to identify hundreds of these rare yellow supergiants, and their more long-lived descendants, the red supergiants in two neighboring galaxies. The Lowell astronomers use these newly identified populations to provide a stringent observational test for the theoretical models which describe how these stars change from blue, to yellow and then to red. These constraints are vital because the behavior of the models in this phase can influence many theoretical predictions, including something as “basic” as what types of stars explode as supernova.