The Milky Way’s Heart May Have Stopped Forming Stars | IFLScience
http://www.iflscience.com/space/the-milky-ways-heart-may-have-stopped-forming-stars/
The closer you get to the center of the galaxy, the more crowded it becomes with stars, at least until reaching the black hole at its core.
However, a survey of the Milky Way’s inner reaches suggests there is a near-complete shortage of young stars around the central hub, throwing
a major query into our view of galactic evolution, and how things may one day look.
Cepheid variables are an exceptionally valuable tool in understanding the universe. These supergiant stars pulse in brightness on a regular
cycle related to how much light they emit on average. By measuring the length of a Cepheid’s cycle, it is possible to work out how bright
it truly is, enabling us to determine its distance. This property has allowed us to measure the scale of our own and nearby galaxies.