RocketSTEM Issue #11 - April 2015 | Page 121

Pair of 68. mammoth stars The image shows a pair of colossal stars, WR 25 and Tr16-244, located within the open cluster Trumpler 16. This cluster is embedded within the Carina Nebula, an immense cauldron of gas and dust that lies approximately 7500 light-years from Earth in the constellation of Carina, the Keel. WR 25 is the brightest, situated near the centre of the image. The neighbouring Tr16-244 is the third brightest, just to the upper left of WR 25. The second brightest, to the left of WR 25, is a low mass star located much closer to the Earth than the Carina Nebula. Credit: NASA, ESA and Jesús Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain) “The most fascinating things we are learning from Hubble in my area of expertise is the study of the most massive stars. These stars are very rare and have very short lives, astronomically speaking, ‘just a few million years’. This is because they are extremely bright, up to a million times brighter than our own star the Sun, which means that they quickly consume all their fuel. “Their fuel consists of hydrogen at first, which they burn into helium and later carbon and oxygen and heavier elements. These are the elements that we ourselves are made of. The oxygen you breath while reading this was ones made in the deep interior of a massive star. Even the tissues that make up your muscles and bones was ones star dust created when a massive star died and exploded.  “One of the big questions astronomers try to answer is how massive is the most massive star. This is a surprisingly hard question to answer. The theoretical models do not give a clear answer. “The only way to answer this questions is with observations. Unfortunately massive stars live in very crowded regions and they shine most of their light in the ultra violet which is blocked by our atmosphere. Here is were the Hubble Telescope made a major difference. Being in space above the atmosphere it can freely observe in colors that are inaccessible from the ground. In addition the superb resolution allows us to look into the centers of some of the densest star clusters.” — Dr. Selma E. de Mink Assistant Professor University of Amsterdam Netherlands