The Hubble Space Telescope has taken a wonderful new image of a huge cluster of stars in our Milky Way Galaxy. Called Liller 1, after astronomer William Liller who discovered it, this group of more than a million stars is located in the direction of our Galaxy’s center. That’s a dusty region, from which regular light is absorbed. much as light from the city center on a smoggy day in Los Angeles doesn’t travel very far. But the Hubble used its ability to see “invisible light” (in this case, infrared rays) to take the image.
On the image, stars much closer to us overload the camera, and look bright and spiky. But you can see the reddish glow of the cluster clearly. Such big groups of stars are called “globular clusters”, since they have a round, globe-like shape. Globular clusters are the oldest things in the Galaxy; we believe they are left over from the time that our galaxy was first forming. Mysteriously, Liller 1 has evidence that some of its stars are much younger than the typical globular cluster. The James Webb Telescope, which is checking out beautifully, will be able to get much better images and data from this cluster, which is about 30,000 light-years away.
On a personal note, William Liller was the astronomer from whom I took my introductory course in astronomy when I was an undergraduate at Harvard. He was not only a good explainer (something I wanted to “grow up” to be,) but a kind man who was generous with his time for his students. I had wanted to be an astronomer since my early teenage years, but his course first showed me the impressive depth of our knowledge of the universe.