Science of Astronomy

Like most stars in the Milky Way, our Sun was born in a cluster of hundreds of new stars in a cloud of glowing gas and dust like the Orion Nebula, then settled down with its siblings in an open star cluster like the Pleiades.  Over the next few hundred million years, as it made its way around the Milky Way, this new cluster of stars was slowly pulled apart by tidal forces and the gravitation pull of passing dust clouds.  Some of the family members may have traveled together for another billion years as a stellar association or a moving group. But like human siblings, they were eventually separated once and for all by the vicissitudes of the outside world. [Read more…] about Our Sun’s Lost Sibling

Enjoy this spectacular new artist’s animation of the Milky Way Galaxy based on data from ESA’s Gaia space telescope. Gaia has changed our impression of the Milky Way. Even seemingly simple ideas about the nature of our galaxy’s central bar and the spiral arms have been overturned. Gaia has shown us that it has more than two spiral arms and that they are less prominent than we previously thought. In addition, Gaia has shown that its central bar is more inclined with respect to the Sun. No spacecraft can travel beyond our galaxy, so we can’t take a selfie, but Gaia is giving us the best insight yet of what our home galaxy looks like. Once all of Gaia’s observations collected over the past decade are made available in two upcoming data releases, we can expect an even sharper view of the Milky Way.