The groupings of stars that form together can vary from a few stars to many hundreds or thousands. Most stars form in multiple star systems, though this formation process is not completely understood. Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration NEWS RELEASE: 2015-16 > In this cluster, Hubble spied a parade of young white dwarfs starting their 40-million-year migration away from the core. The heart of the giant globular star cluster 47 Tucanae reveals the glow of 200,000 stars. That new material is eventually recycled into subsequent generations of stars and planets. The other chemical elements have been and still are being created in the interior of stars through nuclear fusion processes. In the early universe, stars were formed from matter that lacked most elements except for hydrogen and helium. The chemical makeup of stars, revealed through spectroscopy, depends on the material in which they originate. Hubble probes the intricate complexity of these environments, and it has unveiled stars and planetary systems in the making. Robert O'Dell (Rice University), and NASA NEWS RELEASE: 1995-45 >Īstrophysicists have used detailed observations and computer simulations to understand the lifecycles of stars, their chemistry, the nuclear processes within them and the nature of the gas and dust - called the interstellar medium or ISM - out of which stars form. Credit: Mark McCaughrean (Max-Planck-Institute for Astronomy), C. As they evolve, the disks may go on to form planetary systems like our own. The red glow in the center of each disk is a young, newly formed star. These gas disks illustrate an early stage of planetary formation. This would explain why the majority the stars in the Milky Way are paired or in groups of multiple stars. Scientists running three-dimensional computer models of star formation predict that the spinning clouds of collapsing gas and dust may break up into two or three distinct blobs. Not all of the material in the collapsing cloud ends up as part of a star - the remaining dust can become planets, asteroids or comets … or it may remain as dust. One day, this core becomes hot enough to ignite fusion and a star is born. As it collapses, pressure from gravity causes the material at the center to heat up, creating a protostar. These knots contain sufficient mass that the gas and dust can begin to collapse from gravitational attraction. Turbulence from deep within these clouds creates high density regions called knots. One such stellar nursery is the Orion Nebula, an enormous cloud of gas and dust many light-years across. Stars are born in clouds of gas and dust.
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