Until now it was believed that barred spiral galaxies like the Milky Way could not be observed before the universe, estimated to be 13.8 billion years old, reached half of its current age. The Now, Alis Deason, an astrophysicist at Durham University in England, and her colleagues have used nearby galaxies to locate the Milky Way’s edge. The precise diameter is 1.9 million light-years Galaxy Formation and Evolution. Galaxies are home to most of the stars in the universe, and they form the beads of the cosmic jewelry that defines structure on the largest scales. But galaxies haven’t always been around, and they have changed over the universe’s 13.8 billion-year history. Astronomers study the ways galaxies form and evolve The Three-Phase Evolution of the Milky Way. Vedant Chandra, Vadim A. Semenov, Hans-Walter Rix, Charlie Conroy, Ana Bonaca, Rohan P. Naidu, Rene Andrae, Jiadong Li, Lars Hernquist. We illustrate the formation and evolution of the Milky Way over cosmic time, utilizing a sample of 10 million red giant stars with full chemodynamical information Graphic view of our Milky Way Galaxy. The Milky Way Galaxy is organized into spiral arms of giant stars that illuminate interstellar gas and dust. The Sun is in a finger called the Orion Spur. The rotation of our Milky Way in general is derived from observations of the kinematics of gas and stars throughout our galaxy. See for instance a recent compilation of Milky Way rotation curve data from which this figure is taken The rotation curve of the Milky Way as derived from gas kinematics (blue), star kinematics (orange) and masers (black). lJazL.

milky way revolution time