<p>NASA's Hubble Space Telescope has captured a spectacular stellar fireworks display in a small, nearby galaxy, which resembles a skyrocket, with a brilliant blazing head and a long, star-studded tail.<br /><br /></p>.<p>A firestorm of star birth is lighting up one end of the diminutive galaxy Kiso 5639.<br /><br />The dwarf galaxy is shaped like a flattened pancake, but because it is tilted edge-on, it resembles a skyrocket.<br /><br />Kiso 5639 is a rare, nearby example of elongated galaxies that occur in abundance at larger distances, where we observe the universe during earlier epochs.<br /><br />Astronomers suggest that the frenzied star birth is sparked by intergalactic gas raining on one end of the galaxy as it drifts through space.<br /><br />"I think Kiso 5639 is a beautiful, up-close example of what must have been common long ago," said Debra Elmegreen of Vassar College in the US.<br /><br />"The current thinking is that galaxies in the early universe grow from accreting gas from the surrounding neighbourhood. It's a stage that galaxies, including our Milky Way, must go through as they are growing up," Elmegreen said.<br /><br />Observations of the early universe, such as Hubble's Ultra-Deep Field, show that about 10 per cent of all galaxies have these elongated shapes, and are collectively called "tadpoles."<br /><br />But studies of the nearby universe have turned up only a few of these unusual galaxies, including Kiso 5639.<br /><br />The development of the nearby star-making tadpole galaxies, however, has lagged behind that of their peers, which have spent billions of years building themselves up into many of the spiral galaxies seen today.<br /><br />Elmegreen used Hubble's Wide Field Camera 3 to conduct a detailed imaging study of Kiso 5639.<br /><br />The images in different filters unveil information about an object by dissecting its light into its component colours. Hubble's crisp resolution helped researchers analyse the giant star-forming clumps in Kiso 5639 and determine the masses and ages of the star clusters.<br /><br />The researchers selected Kiso 5639 from a spectroscopic survey of 10 nearby tadpole galaxies. The observations showed that in most of those galaxies, including Kiso 5639, the gas composition is not uniform.<br /><br />The bright gas in the galaxy's head contains fewer heavier elements (collectively called "metals"), such as carbon and oxygen, than the rest of the galaxy.<br /><br />Stars consist mainly of hydrogen and helium, but cook up other "heavier" elements. When the stars die, they release their heavy elements and enrich the surrounding gas.<br /><br />"The metallicity suggests that there has to be rather pure gas, composed mostly of hydrogen, coming into the star-forming part of the galaxy, because intergalactic space contains more pristine hydrogen-rich gas," Elmegreen said.<br /><br />"Otherwise, the starburst region should be as rich in heavy elements as the rest of the galaxy," she said. </p>
<p>NASA's Hubble Space Telescope has captured a spectacular stellar fireworks display in a small, nearby galaxy, which resembles a skyrocket, with a brilliant blazing head and a long, star-studded tail.<br /><br /></p>.<p>A firestorm of star birth is lighting up one end of the diminutive galaxy Kiso 5639.<br /><br />The dwarf galaxy is shaped like a flattened pancake, but because it is tilted edge-on, it resembles a skyrocket.<br /><br />Kiso 5639 is a rare, nearby example of elongated galaxies that occur in abundance at larger distances, where we observe the universe during earlier epochs.<br /><br />Astronomers suggest that the frenzied star birth is sparked by intergalactic gas raining on one end of the galaxy as it drifts through space.<br /><br />"I think Kiso 5639 is a beautiful, up-close example of what must have been common long ago," said Debra Elmegreen of Vassar College in the US.<br /><br />"The current thinking is that galaxies in the early universe grow from accreting gas from the surrounding neighbourhood. It's a stage that galaxies, including our Milky Way, must go through as they are growing up," Elmegreen said.<br /><br />Observations of the early universe, such as Hubble's Ultra-Deep Field, show that about 10 per cent of all galaxies have these elongated shapes, and are collectively called "tadpoles."<br /><br />But studies of the nearby universe have turned up only a few of these unusual galaxies, including Kiso 5639.<br /><br />The development of the nearby star-making tadpole galaxies, however, has lagged behind that of their peers, which have spent billions of years building themselves up into many of the spiral galaxies seen today.<br /><br />Elmegreen used Hubble's Wide Field Camera 3 to conduct a detailed imaging study of Kiso 5639.<br /><br />The images in different filters unveil information about an object by dissecting its light into its component colours. Hubble's crisp resolution helped researchers analyse the giant star-forming clumps in Kiso 5639 and determine the masses and ages of the star clusters.<br /><br />The researchers selected Kiso 5639 from a spectroscopic survey of 10 nearby tadpole galaxies. The observations showed that in most of those galaxies, including Kiso 5639, the gas composition is not uniform.<br /><br />The bright gas in the galaxy's head contains fewer heavier elements (collectively called "metals"), such as carbon and oxygen, than the rest of the galaxy.<br /><br />Stars consist mainly of hydrogen and helium, but cook up other "heavier" elements. When the stars die, they release their heavy elements and enrich the surrounding gas.<br /><br />"The metallicity suggests that there has to be rather pure gas, composed mostly of hydrogen, coming into the star-forming part of the galaxy, because intergalactic space contains more pristine hydrogen-rich gas," Elmegreen said.<br /><br />"Otherwise, the starburst region should be as rich in heavy elements as the rest of the galaxy," she said. </p>