The boldness of our collective efforts to comprehend the universe inspires us, while the dimensions of space and time humble us. The beauty of the night sky and its rhythms are at once stunning and compelling. As a community of citizens fortunate to live in a society that supports them generously, astronomers believe strongly that “from those to whom much is given, much is asked.” It is in that spirit that the committee offers below an accounting of astronomy’s more tangible contributions to broader societal goals.Īstronomy excites the imagination. ![]() Exploring frontiers of unimaginable mystery and beauty, astronomy speaks compellingly to these fundamental questions.Īs researchers, astronomers experience the excitement of discovery most vividly and are the first to glimpse new answers to ancient questions. Perhaps the most persuasive, but least quantifiable, justifications lie in the importance American society has always attached to exploring new frontiers, and in the deep human desire to understand how we came to be, the kind of universe we live in, whether we are alone, and what our ultimate fate will be. To take these next steps will require significant investments of both imagination and public resources.īecause the magnitude of these investments will be large, it is fair to ask why astronomical research should merit such support. ![]() Astronomers stand poised to examine the epoch when galaxies similar to our Milky Way first took form, to image Earth-like planets beyond our solar system, and to learn whether some show evidence of life. In the decades ahead, the pace of discovery-remarkable as it has been over the past-will accelerate. These startling advances are the result not only of the collective creative efforts of scientists and engineers throughout the United States and around the world, but also of the generous investments in astronomy over much of the past 50 years by federal and state governments, foundations, and individuals. However, it is still only a fudge factor, and such things are inherently uncertain.Astronomical discoveries of the past decade-images of the hot universe at an epoch before the first galaxies and stars emerged, of other solar systems beginning to take form, of planetary systems beyond our own-have captured the imagination of scientists and citizens alike. I think he did a perfectly reasonable job in deriving the best-guess fudge factor for this. ![]() "He basically takes an observed luminosity-based, and thus already soft, mass estimate of 130 solar masses for a single star, and then applies some fudge factor to get 150 solar masses. "My concern is the firmness which Figer attaches to his 150-solar-mass upper limit," says University of Florida astronomer Steve Eikenberry. "The existence of a sharp cutoff has not been demonstrated observationally with such significance before." "The 100- to 150-solar-mass range has indeed been talked about as a limit for a long time, but theory does not derive it with any precision," says University of California, Santa Cruz astrophysicist Stan Woosley. His result is consistent with studies of nine other young star clusters by a group led by Sally Oey (University of Michigan). Adopting a conservative approach, Figer concludes that this 2-million-year-old cluster produced no stars greater than 150 solar masses. The cluster, known as the Arches Cluster, resides near the galactic center and contains thousands of stars, some of which shine with millions of times the intensity of the Sun. The most luminous (and hence most massive) stars in the cluster show a sharp cutoff in initial mass at about 130 solar masses. Figer (Space Telescope Science Institute) presents Hubble Space Telescope observations of the richest young star cluster in the Milky Way Galaxy. In a paper published this week in the British journal Nature, Donald F. Now, astronomers have observational evidence that this thinking is largely correct. Stars above this mass limit should generate so much light that the sheer pressure of their own radiation blows off enormous amounts of mass, quickly whittling them down to 100 to 150 solar masses. ![]() In recent decades, many astronomers believed that limit was somewhere in the neighborhood of 100 to 150 solar masses for stars forming in the modern-day universe. Advertising Information Sky & Telescope MagazineĪstronomers have long wondered what is the upper mass limit for stars.
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