http://www.cfa.harvard.edu/news/Weekly Science Updateen-us http://www.cfa.harvard.edu/news/2009/su200947.htmlNovember 20, 2009: The famous Orion Nebula is the closest nursery of massive young stars to the earth, and is about 1300 light-years away. The nebula is part of a giant molecular cloud that hosts several clusters of hot young stars, with the brightest young star in the nebula, called Source I, shining with the luminosity of 100,000 suns. http://www.cfa.harvard.edu/news/2009/su200946.htmlNovember 13, 2009: The nucleus of an active galaxy, an AGN, contains a massive black hole that is vigorously accreting material. In the process it typically ejects jets of particles and radiates brightly at many wavelengths, in particular at X-ray wavelengths. http://www.cfa.harvard.edu/news/2009/su200945.htmlNovember 06, 2009: Astronomers have just published the discovery of the farthest known object in the cosmos: a star that exploded when the universe was only 630 million years old -- only 4.6% of its current age. http://www.cfa.harvard.edu/news/2009/su200944.htmlOctober 30, 2009: Stars, the most familiar objects in the night sky, make up only a tiny percentage of the total amount of matter in the universe -- about 2%. http://www.cfa.harvard.edu/news/2009/su200943.htmlOctober 23, 2009: The Orion Nebula is one of the most beautiful sights of the winter night sky, its gas and dust glowing from the intense ultraviolet radiation of a cluster of massive young stars. http://www.cfa.harvard.edu/news/2009/su200942.htmlOctober 16, 2009: Some dramatic galaxies eject gigantic, collimated jets of ionized gas millions of light-years long, powered by the massive black holes at their centers. http://www.cfa.harvard.edu/news/2009/su200941.htmlOctober 09, 2009: Most stars form in clusters. Recent studies of nearby star forming regions find that about three-quarters of their young stars are located in groups with ten or more members. http://www.cfa.harvard.edu/news/2009/su200940.htmlOctober 02, 2009: Of the roughly 350 known exoplanets (i.e., extrasolar planets), the one orbiting the star HD149026 is unique. It has a mass comparable to that of Saturn but is much smaller in size, indicating that it is made up of a denser material such as ice or rocks. http://www.cfa.harvard.edu/news/2009/su200939.htmlSeptember 25, 2009: Gamma-rays are the most energetic known form of electromagnetic radiation, with each gamma ray being at least one hundred thousand times more energetic than an optical light photon. http://www.cfa.harvard.edu/news/2009/su200938.htmlSeptember 18, 2009: Supernovae, the explosive deaths of massive stars, disburse into space all of the chemical elements that were spawned inside the progenitor stars. http://www.cfa.harvard.edu/news/2009/su200937.htmlSeptember 11, 2009: Our understanding of star formation leans heavily on observations of stars like the sun, namely, those that are modest in mass and that are born and evolve at a relatively leisurely pace. http://www.cfa.harvard.edu/news/2009/su200936.htmlSeptember 04, 2009: Among the most astounding, unexpected, and important achievements of the past century (or even more) have been the discoveries of dark matter and dark energy, collectively dubbed the "dark sector." http://www.cfa.harvard.edu/news/2009/su200935.htmlAugust 28, 2009: The Central Molecular Zone (CMZ) of our galaxy is a giant complex of molecular gas and dust situated in the innermost 700 light-years of the Milky Way. http://www.cfa.harvard.edu/news/2009/su200934.htmlAugust 21, 2009: IC348 is a glowing nebula of young stars, hot gas, and cold dust seen in the direction of the constellation of Perseus. It is the nearest rich cluster of young stars to earth, being only about one thousand light-years away. http://www.cfa.harvard.edu/news/2009/su200933.htmlAugust 14, 2009: The existence of black holes is one of the most amazing and bizarre predictions of Einstein's theory of gravity.