Scientists have estimated the distance from the sun to several single pulsating stars scattered around the Milky Way and mapped the Galaxy on a broader scale than ever before. Their new 3D map offers a wide view of the Milky Way among the stars and shows that its warped stellar disc has an S-like structure.
Our map shows the Milky Way disk is not flat. It is warped and twisted. This is the first time we can use individual objects to show this in three dimensions.
Przemek Mroz, Study Co-Author, University of Warsaw
Most current understanding of the structure and spiral shape of the Galaxy is based on indirect quantifications to celestial landmarks and conclusions depending on other galaxies in the universe. The galactic map developed using such limited observations is, however, still incomplete.
Similar to several lighthouses on distant foggy shores, classical Cepheid variable stars—enormous young stellar bodies that blaze several thousand times brighter than the sun—pulsate at regular intervals and are visible through the huge clouds of interstellar dust that often hide dimmer stellar bodies.
Scientists accurately measured the distances to these stars by using the regular changes in their brightness. Dorota Skowron and her team mapped the distance to over 2,400 Cepheids across the Milky Way. A majority of these Cepheids were spotted by the Optical Gravitational Lensing Experiment (OGLE)—a study that reveals over twice the number of known galactic classical Cepheids.
Skowron and her colleagues found the 3D coordinates of each distant pulsating star with respect to the sun and developed a large-scale 3D map of the Milky Way galaxy. The new chart shows and helps limit the earlier observed shape of the Galaxy’s warped stellar disk.