“In order to collect such a complete and pure sample of classical cepheids, one has to regularly observe the whole Milky Way for a long period of time. The new map illustrates and helps constrain the previously observed shape of the galaxy’s warped stellar disc. By determining the 3D coordinates of each distant pulsing star relative to our sun, the team built a large scale 3D model of the Milky Way. Mroz, Skowron and their colleagues at the Warsaw University Astronomical Observatory charted the distance to more than 2,400 Cepheids throughout the Milky Way, most of which were identified by the Optical Gravitational Lensing Experiment ( OGLE) – a project that more than doubled the number of known galactic classical cepheids. Using the periodic variations in their brightness, the distances to these stars can be precisely determined. “We could say that our observations of distant galaxies help us learn about our Milky Way,” says Skowron. "Our map shows the Milky Way disk is not flat.
Like so many lighthouses on distant foggy shores, classical cepheid variable stars - massive young stellar bodies that burn hundreds, if not thousands of times brighter than our own sun - pulsate at regular intervals and are visible through the vast clouds of interstellar dust that often obscure dimmer stellar bodies. However, the galactic map drafted by those limited observations remains incomplete. Much of the current understanding of the spiral shape and structure of our galaxy is built upon indirect measurements to celestial landmarks and inferences based on other galaxies in the universe. “This is the first time we can use individual objects to show this in three dimensions.” It is warped and twisted,” co-author Przemek Mroz said in a statement. “Our map shows the Milky Way disk is not flat.
Skowron / OGLE / Astronomical Observatory, University of Warsaw Dr Skowron and her team had to make 153,704,543,662 individual observations to reach this conclusion J.
0 kommentar(er)
