Peering into Orion nebula's stellar nursery.Astronomers have viewed with greater clarity than ever before a dust-cloaked region of starbirth in the Milky Way Milky Way, the galaxy of which the sun and solar system are a part, seen as a broad band of light arching across the night sky from horizon to horizon; if not blocked by the horizon, it would be seen as a circle around the entire sky. , The violent interactions they recorded there may shed new light on luminous knots of gas, known as Herbig-Haro objects, whose origin has been controversial ever since they were discovered in the late 1940s. Australian astronomers David A. Allen ol the Anglo-Australian Observatory The Anglo-Australian Observatory (AAO) is an optical astronomy observatory with its headquarters in suburban Sydney, Australia. It is jointly funded by the United Kingdom and Australian governments and operates the 3.9 metre Anglo-Australian Telescope (AAT) and 1. in Epping and Michael G. Burton of the University of New South Wales The University of New South Wales, also known as UNSW or colloquially as New South, is a university situated in Kensington, a suburb in Sydney, New South Wales, Australia. used an infrared array to probe the interior of the dusty Orion nebula, a molecular cloud that harbors the stellar nursery nearest to Earth. They report their findings in the May 6 NATURE. Their striking false-color images trace the high- and low-energy scenes from a startling star·tle v. star·tled, star·tling, star·tles v.tr. 1. To cause to make a quick involuntary movement or start. 2. To alarm, frighten, or surprise suddenly. See Synonyms at frighten. story unfolding near the brightest star, dubbed IRc2, in Orion. Allen and Burton believe that the Herbig-Haro objects they recorded with the 3.9-meter Anglo-Australian Telescope were triggered by blobs of gas ejected from the star a mere 1,000 years earlier. Plowing into surrounding gas, the blobs ionized i·on·ize tr. & intr.v. i·on·ized, i·on·iz·ing, i·on·iz·es To convert or be converted totally or partially into ions. i iron atoms, thus taking on a false-green cast. Surrounding many of these blobs are structures that resemble the bow shocks created when a boat rushes across a lake. Allen suggests that these bow shocks lack the punch to ionize i·on·ize v. To dissociate atoms or molecules into electrically charged atoms or radicals. i  on·iz iron but can excite molecular hydrogen, depicted as a red glow, Other researchers say the images don't rule out alternative explanations for forming Herbig-Haro objects in Orion. C.R. O'Dell of Rice University in Houston notes that these knots might be formed when a slow-moving jet of gas from a star strikes a stationary wall of gas in the interstellar medium. Alternatively, a last-moving jet may create knots of bright emissions as it shocks and pushes out surrounding gas. Allen says that a narrow jet could not account for the wide angular spread of the knots. However, John Dyson of the University of Manchester The University of Manchester is a university located in Manchester, England. With over 40,000 students studying 500 academic programmes, more than 10,000 staff and an annual income of nearly £600 million it is the largest single-site University in the United Kingdom and receives in England suggests that a jet wiggling like the end of a loosely held garden hose might explain the distribution. Researchers, including Allen, agree that more than one mechanism may create Herbig-Haro objects. In any case, writes Dyson in a commentary accompanying the NATURE article, the findings "show that many [violent] surprises are in store as modern observational techniques... probe into hitherto unexplored regions of interstellar space." |
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