Celestial Mystery Solved
The winking star created a sensation when Professor of Astronomy William Herbst and Catrina Hamilton-Drager Ph.D. ’04 introduced it at an astronomy conference three years ago.
The two reported that the star was fading in and out in an unprecedented manner and suggested that a nascent planetary cloud might be responsible.
The findings, which attracted substantial media coverage, set astronomers worldwide to working on explanations for the behavior of KH 15D, approximately 2,400 light years away.
Now, some 30 scientific papers later, the mystery has been solved. Researchers at the Harvard-Smithsonian Center for Astrophysics and at the University of California, Berkeley, reported solutions within a day of each other. In August, the New York Times carried a feature story about the star in its Connecticut section.
The story quoted Joshua Winn, a postdoctoral student at Harvard who helped solve the mystery: “One of the most beautiful things out of this story is that it was triggered by a small telescope on an East Coast campus, which is supposed to have terrible weather and be terrible for astronomy.”
Winn suggested that the winking could be explained by the presence of two stars orbiting each other in an eccentric fashion, with one star out of sight and a wobbling screen of gas and dust in front of them.
Sure enough, Hamilton-Drager, who now teaches physics at the University of Minnesota, went back through old Wesleyan data and found that in 1995 the second star had shown itself just when the theory said it should appear.
Herbst said the star continues to pose mysteries that he and others are pursuing.
The Times also quoted Herbst reflecting on his motivation for doing this research: “We’re not doing this for money. Some people are doing it for the esteem of their colleagues, which is very hard to get. Basically, I’m doing it for fun because it’s just extraordinarily fun to make these discoveries. It’s pursuit of knowledge for its own sake.