[New post] Astronomy Photo of the Day: 3/15/15 — NGC 4603

New post on From Quarks to Quasars Astronomy Photo of the Day: 3/15/15 — NGC 4603 by Jaime Trosper Image Credit: NASA/JPL/STScI Meet NGC 4603: a galaxy found approximately 100 million light-years from Earth in the Cepheus constellation. In this remarkable image, we see the features that give it its spiral appearance, from the well-defined spiral arms themselves, to the contrasting lanes of black dust. This image also affords us the chance to see its huge, blue-white stars, and it older collection of red-tinged stars, many of which teeter on the edge of life and death—about to explode as supernovae. From a scientific point of view, NGC 4603 is much more than its beauty; it remains one of the most useful galaxies for measuring extragalactic distances, all because of its large volume of Cepheid variable stars. Stars within this group are known for their propensity to pulsate at regular intervals, and astronomers have identified over 36 Cepheids in this galaxy alone. Moreover, it's one of the most distant galaxies Cepheids have been discovered in. It was also used to measure the Hubble Constant (that is, the rate at which the universe is expanding, and how fast galaxies are receding from each other). Finally, NGC 4603, along with approximately 100 other galaxies, belong to a galaxy group called the Centaurus Cluster, in Cen30 specifically. Jaime Trosper | March 15, 2015 at 8:32 am | Tags: APOD, APotD, Cen30, Centaurus Cluster,Cepheid Variable Stars, Cosmic Distance Ladder, Galaxies, Hubble's Constant, NGC 4603,Pulsating Stars, Supernovae | Categories: Astronomy Photos | URL: http://www.fromquarkstoquasars.com/?p=37673