By Ron Cowen
Aided by a gravitational zoom lens, astronomers have discovered the hottest, brightest, and most crowded star-forming region observed so far. Ablaze with a million newborn stars, the Lynx arc, named after the constellation in which it resides, lies 12 billion light-years from Earth. Telescope images of the Lynx arc thus reveal what conditions were like when the now 14-billion-year-old universe was only 2 billion years old. At that time, only a few generations of stars had lit up the cosmos.
With a surface temperature of some 80,000C, the Lynx stars blaze twice as hot as the brightest star in our galaxy’s Orion star-forming region does. That heat and the stars’ white-blue color suggest that all these newborns are about 10 to 20 times more massive than the sun. In comparison, the Orion region has only four such massive stars.