Astronomers using the unique ultraviolet capabilities of the NASA/ESA Hubble Space Telescope have identified nine monster stars with masses over 100 times the mass of the Sun in the star cluster R136. This makes it the largest sample of very massive stars identified to date. The results, which will be published in the Monthly Notices of the Royal Astronomical Society, raise many new questions about the formation of massive stars. (learn more)
Source: eso1540 — Science Release
Using ESO’s Very Large Telescope, an international team of astronomers have found the hottest and most massive double star with components so close that they touch each other. The two stars in the extreme system VFTS 352 could be heading for a dramatic end, during which the two stars either coalesce to create a single giant star, or form a binary black hole. (learn more)
Credit: ESO Photo Release eso1420
The little-known cloud of cosmic gas and dust called Gum 15 is the birthplace and home of hot young stars. Beautiful and deadly, these stars mould the appearance of their mother nebula and, as they progress into adulthood, will eventually also be the death of her. (learn more)
Source: ESO Science Release eso1337
An international team led by astronomers in Brazil has used ESO’s Very Large Telescope to identify and study the oldest solar twin known to date. Located 250 light-years from Earth, the star HIP 102152 is more like the Sun than any other solar twin — except that it is nearly four billion years older. This older, but almost identical, twin gives us an unprecedented chance to see how the Sun will look when it ages. The new observations also provide an important first clear link between a star’s age and its lithium content, and in addition suggest that HIP 102152 may be host to rocky terrestrial planets.(read more)
Source: ESO Science Release eso1323
Astronomers expect that stars like the Sun will blow off much of their atmospheres into space near the ends of their lives. But new observations of a huge star cluster made using ESO’s Very Large Telescope have shown — against all expectations — that a majority of the stars studied simply did not get to this stage in their lives at all. The international team found that the amount of sodium in the stars was a very strong predictor of how they ended their lives. (read more)
Source: NASA Science
An international team of astronomers has caught a star in the act of devouring one of its planets. BD+48 740, a red giant they observed using the 9.2-meter Hobby-Eberly Telescope at the McDonald Observatory in Texas, appears to have the fumes of a scorched planet in its atmosphere. This is consistent with a rocky world, recently destroyed.
Could the same thing happen to Earth?
Yes indeed, says Alex Wolszczan, a member of the research team from Penn State University: "A similar fate may await the inner planets in our solar system when the sun becomes a red giant some five billion years from now."
Source: NASA Press Release
Images from NASA's Wide-field Infrared Survey Explorer (WISE) reveal an old star in the throes of a fiery outburst and spraying the cosmos with dust. The findings offer a rare, real-timelook at the process by which stars like our sun seed the universe with building blocks for other stars, planets and even life.
The star, catalogued as WISE J180956.27-330500.2, was discovered in images taken during the WISE survey in 2010, the most detailed infrared survey to date of the entire celestial sky. It stood out from other objects because it glowed brightly with infrared light. When compared to images taken more than 20 years ago, astronomers found the star was 100 times brighter.
"We were not searching specifically for this phenomenon, but because WISE scanned the whole sky, we can find such unique objects," said Poshak Gandhi of the Japan Aerospace Exploration Agency (JAXA), lead author of a new paper to be published in the Astrophysical Journal Letters.
Results indicate the star recently exploded with copious amounts of fresh dust, equivalent in mass to our planet Earth. The star is heating the dust and causing it to glow with infrared light.
"Observing this period of explosive change while it is actually ongoing is very rare," said co-author Issei Yamamura of JAXA. "These dust eruptions probably occur only once every 10,000 years in the lives of old stars, and they are thought to last less than a few hundred years each time. It's the blink of an eye in cosmological terms."
The aging star is in the "red giant" phase of its life. Our own sun will expand into a red giant in about 5 billion years. When a star begins to run out of fuel, it cools and expands. As the star puffs up, it sheds layers of gas that cool and congeal into tiny dust particles. This is one of the main ways dust is recycled in our universe, making its way from older stars to newborn solar systems. The other way, in which the heaviest of elements are made, is through the deathly explosions, or supernovae, of the most massive stars.
"It's an intriguing glimpse into the cosmic recycling program," said Bill Danchi, WISE program scientist at NASA Headquarters in Washington. "Evolved stars, which this one appears to be, contribute about 50 percent of the particles that make up humans."
Astronomers know of one other star currently pumping out massive amounts of dust. Called Sakurai's Object, this star is farther along in the aging process than the one discovered recently by WISE.
After Poshak and his team discovered the unusual, dusty star with WISE, they went back to look for it in previous infrared all-sky surveys. The object was not seen at all by the Infrared Astronomical Satellite (IRAS), which flew in 1983, but shows up brightly in images taken as part of the Two Micron All-Sky Survey (2MASS) in 1998.
Poshak and his colleagues calculated the star appears to have brightened dramatically since 1983. The WISE data show the dust has continued to evolve over time, with the star now hidden behind a very thick veil. The team plans to follow up with space and ground-based telescopes to confirm its nature and to better understand how older stars recycle dust back into the cosmos.
NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., manages and operates WISE for NASA's Science Mission Directorate in Washington. The spacecraft was put into hibernation mode after it scanned the entire sky twice, completing its main objectives. The principal investigator for WISE, Edward Wright, is at the University of California, Los Angeles. The mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology (Caltech) in Pasadena. Caltech manages JPL for NASA.
The IRAS mission was a collaborative effort between NASA (JPL), the Netherlands and the United Kingdom. The 2MASS mission was a joint effort between Caltech, the University of Massachusetts and NASA (JPL). Data are archived at the Infrared Processing and Analysis Center at Caltech.
For more information about WISE, visit:
As the city gears up for Dublin: City of Science 2012, we take a journey with amateur astronomer and artist Deirdre Kelleghan whose equal passion for science and art is demonstrated in her work. Deirdre is a Discover Science and Engineering Science Ambassador 2012, Vice Chair of the Irish Federation of Astronomical Societies, National Co-ordinator for Astronomers Without Borders, as well as being UNAWE rep in Ireland. Deirdre will also be contributing to the Dublin City Public Libraries programme of events for Dublin: City of Science 2012.
The city on a sun drenched day. The Spire reflects and swirls the vibrant life of Dubliners mingled with mirrored clouds and the dominant blue light from our nearest star. Flower sellers petals are jollied by the brightness. Mica within the Liffey’s walls sparkle; ice cream melts down smiling faces. Celtic skin hovers in winters long lost vitamin, a gift from the sun, 93 million miles from the city. We enjoy our sophisticated fully functioning star, down here on one of the left over bits from its formation.
When we analyse light from our sun or any star we can see the arrangement of elements within its spectra. Looking into a star’s pattern of elements is like looking at the code of that star, its personal finger print, its DNA. Humans are bound together by the same elements which were created during the birth and death of stars. Our essence is ultimately recycled throughout unimaginable eons of time, black space and accreted molecular clouds.
ESA’s Herschel Space Observatory has studied the dusty belt around the nearby star Fomalhaut. The dust appears to be coming from collisions that destroy up to thousands of icy comets every day. (read more)
Source: ESO Science Release eso1216
A new observatory still under construction has given astronomers a major breakthrough in understanding a nearby planetary system and provided valuable clues about how such systems form and evolve. Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that planets orbiting the star Fomalhaut must be much smaller than originally thought. This is the first published science result from ALMA in its first period of open observations for astronomers worldwide.(read more)
Astronomers using the NASA/ESA Hubble Space Telescope have found a cluster of young blue stars surrounding a mid-sized black hole called HLX-1. The discovery suggests that the black hole formed in the core of a now-disintegrated dwarf galaxy. The findings have important implications for understanding the evolution of supermassive black holes and galaxies. (read more)
Source: ESO Science Release eso1147
ESO's Very Large Telescope has picked up the fastest rotating star found so far. This massive bright young star lies in our neighbouring galaxy, the Large Magellanic Cloud, about 160 000 light-years from Earth. Astronomers think that it may have had a violent past and has been ejected from a double star system by its exploding companion.(read more)
Source: ESO Science Release eso1148
Astronomers have obtained the best images ever of a star that has lost most of its material to a vampire companion. By combining the light captured by four telescopes at ESO’s Paranal Observatory they created a virtual telescope 130 metres across with vision 50 times sharper than the NASA/ESA Hubble Space Telescope. Surprisingly, the new results show that the transfer of mass from one star to the other in this double system is gentler than expected.
The astronomers observed the unusual system SS Leporis in the constellation of Lepus (The Hare), which contains two stars that circle around each other in 260 days. The stars are separated by only a little more than the distance between the Sun and the Earth, while the largest and coolest of the two stars extends to one quarter of this distance — corresponding roughly to the orbit of Mercury. Because of this closeness, the hot companion has already cannibalised about half of the mass of the larger star.(read more)
Source: NASA Science Casts
A NASA space telescope named "GALEX" has found stars forming in extreme galactic environments, places where researchers thought stars should not be. The finding could affect astronomy much as the discovery of microbial extremophiles affected biology in the 1970s.
Source: ESO Photo Release eso1136
Astronomers have used ESO’s Very Large Telescope to image a colossal star that belongs to one of the rarest classes of stars in the Universe, the yellow hypergiants. The new picture is the best ever taken of a star in this class and shows for the first time a huge dusty double shell surrounding the central hypergiant. The star and its shells resemble an egg white around a yolky centre, leading the astronomers to nickname the object the Fried Egg Nebula. (learn more)
A nearby star, named CoRoT-2a, has a planet in close orbit around it. The separation between the star and planet is only about 3 percent of the distance between the Earth and the Sun, causing some exotic effects not seen in our solar system. Chandra has now found that the planet is under heavy X-ray bombardment from its star. (Read more)
Source: ESO Photo Release eso1133
ESO’s New Technology Telescope (NTT) has captured a striking image of the open cluster NGC 2100. This brilliant star cluster is around 15 million years old, and located in the Large Magellanic Cloud, a nearby satellite galaxy of the Milky Way. The cluster is surrounded by glowing gas from the nearby Tarantula Nebula.(read more)
Source:ESO Science Release eso1132
A team of European astronomers has used ESO’s Very Large Telescope (VLT) to track down a star in the Milky Way that many thought was impossible. They discovered that this star is composed almost entirely of hydrogen and helium, with only remarkably small amounts of other chemical elements in it. This intriguing composition places it in the “forbidden zone” of a widely accepted theory of star formation, meaning that it should never have come into existence in the first place. The results will appear in the 1 September 2011 issue of the journal Nature. (read more)