On average, how many stars would we have to search before we would expect to hear a signal? N1 = 4.55×107 How does your answer change if there are only 120 civilizations instead of 1.10×104? Milky Way Not Your Average Spiral Galaxy By Will Parker on August 17, 2005 in News Using NASA’s Spitzer Space Telescope, astronomers have been conducting a comprehensive structural analysis of our galaxy and found intriguing new evidence that the Milky Way is quite different from what we believe to be an ordinary spiral galaxy. If you look at the bigger ones, big ellipticals are bigger than big spirals. The content is provided for information purposes only. The super spiral observations suggest no non-Newtonian dynamics is required.Despite being the most massive spiral galaxies in the universe, super spirals are actually underweight in stars compared to what would be expected for the amount of dark matter they contain. The spiral is 522,000 light-years across from armtip to armtip, which makes NGC 6872 about 5 times the size of the Milky Way. Super spirals are exceptional in almost every way. [NCG 6872's enormous size and odd appearance are the consequence of its gravitational interaction with a neighbor galaxy called IC 4970, which contains just 20 percent of NGC 6872's mass, researchers said.Computer simulations suggest that IC 4970 made its closest approach about 130 million years ago, stirring up a burst of activity in certain parts of NCG 6872. The bulge of a spiral galaxy is composed primarily of old, red stars. But it has only now been crowned champion, after detailed study of data gathered by a number of instruments, including NASA's "Without GALEX's ability to detect the ultraviolet light of the youngest, hottest stars, we would never have recognized the full extent of this intriguing system," lead scientist Rafael Eufrasio, of NASA's Goddard Space Flight Center in Greenbelt, Md., and the Catholic University of America, said in a statement. Medical Xpress covers all medical research advances and health news Tech Xplore covers the latest engineering, electronics and technology advances Science X Network offers the most comprehensive sci-tech news coverage on the web "The northeastern arm of NGC 6872 is the most disturbed and is rippling with star formation, but at its far end, visible only in the ultraviolet, is an object that appears to be a tidal dwarf galaxy similar to those seen in other interacting systems," Duilia de Mello, a professor of astronomy at Catholic University, said in a statement.NGC 6872's bar, which links the galaxy's arms and its central regions, is also huge. Assume there are 500 billion stars in the galaxy. Astronomers have crowned the universe's largest known spiral galaxy, a spectacular behemoth five times bigger than our own Milky Way.The title-holder is now NGC 6872, a barred spiral found 212 million light-years away in the southern constellation Pavo, researchers announced today (Jan. 10). Future US, Inc. 11 West 42nd Street, 15th Floor, "Super spirals are extreme by many measures," says Patrick Ogle of the Space Telescope Science Institute in Baltimore, Maryland. An average spiral galaxy, like the Milky Way, spins at speeds of 468,000mph (753,172kmh). N2 = 4.17×109 This site uses cookies to assist with navigation, analyse your use of our services, and provide content from third parties. The Milky Way, an average spiral galaxy, spins at a speed of 130 miles per second (210 km/sec) in our Sun's neighborhood. The arms of a spiral galaxy have lots of gas and dust, and they are often areas where new stars are constantly forming. That amount of dark matter would normally contain a group of galaxies rather than a single galaxy. The disk is a region of star formation and has a great deal of gas and dust. Get weekly and/or daily updates delivered to your inbox. Apart from any fair dealing for the purpose of private study or research, no Dr Patrick Ogle. We do not guarantee individual replies due to extremely high volume of correspondence. The most massive halo that Ogle measured contains enough dark matter to weigh at least 40 trillion times as much as our Sun. By using our site, you acknowledge that you have read and understand our Very little star formation goes on in the bulge.