European Association for Astronomy Education

Source: ESO Photo Release eso1209

APEX image of a star-forming filament in Taurus.
Image credits: ESO/APEX (MPIfR/ESO/OSO)/A. Hacar et al./Digitized Sky Survey 2.
Acknowledgment: Davide De Martin.

A new image from the APEX (Atacama Pathfinder Experiment) telescope in Chile shows a sinuous filament of cosmic dust more than ten light-years long. In it, newborn stars are hidden, and dense clouds of gas are on the verge of collapsing to form yet more stars. It is one of the regions of star formation closest to us. The cosmic dust grains are so cold that observations at wavelengths of around one millimetre, such as these made with the LABOCA camera on APEX, are needed to detect their faint glow.(read more)

Source: ESO Photo Release eso1207

 
The star formation region NGC 3324. Image credits: ESO.

This new view shows a stellar nursery called NGC 3324. It was taken using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. The intense ultraviolet radiation from several of NGC 3324's hot young stars causes the gas cloud to glow with rich colours and has carved out a cavity in the surrounding gas and dust. (read more)

Source: ESA/Hubble Photo Release heic1118

Hubble view of star-forming region S106. Image credits:NASA & ESA.

Hubble’s Wide Field Camera 3 has captured this image of a giant cloud of hydrogen gas illuminated by a bright young star. The image shows how violent the end stages of the star-formation process can be, with the young object shaking up its stellar nursery.(read more)

Source: ESO Photo Release eso1145

The cold stellar formation clouds in the Carina Nebula, seen by APEX.
Image credits: ESO/APEX/T. Preibisch et al. (Submillimetre);
N. Smith, University of Minnesota/NOAO/AURA/NSF (Optical)

Observations made with the APEX telescope in submillimetre-wavelength light reveal the cold dusty clouds from which stars form in the Carina Nebula. This site of violent star formation, which plays host to some of the highest-mass stars in our galaxy, is an ideal arena in which to study the interactions between these young stars and their parent molecular clouds. (read more)

Source: Chandra

30 Doradus.
Image credits: X-ray: NASA/CXC/PSU/L.Townsley et al.;
Infrared: NASA/JPL/PSU/L.Townsley et al.

Chandra has taken another outstanding image this time of the star-forming region, 30 Doradus, is one of the largest located close to the Milky Way that is found in the neighboring galaxy Large Magellanic Cloud. About 2,400 massive stars in the center of 30 Doradus, also known as the Tarantula Nebula, are producing intense radiation and powerful winds as they blow off material.(read more)

Source: ESA

Artist's impression illustrates an icy protoplanetary disc around the young star TW Hydrae.
Credits: ESA/NASA/JPL-Caltech

ESA’s Herschel space observatory has found evidence of water vapour emanating from ice on dust grains in the disc around a young star, revealing a hidden ice reservoir the size of thousands of oceans. (read more)

Source: Chandra

Credits: X-ray: NASA/CXC/CfA/S.Wolk; IR: NASA/JPL/CfA/S.Wolk

A nebula with active star formation about 9,200 light years from Earth. (read the hole story)

Source: ESO Photo Release eso1133

The brilliant star cluster NGC 2100 lies in the Large Magellanic Cloud.
Image credits: ESO.

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: ESA/Hubble Science Release heic1113

Astronomers have combined two decades of Hubble observations to make unprecedented movies revealing never-before-seen details of the birth pangs of new stars. This sheds new light on how stars like the Sun form.(read more)

Source: NASA News

Artist's conception of a "Y dwarf".
Image credits: NASA/JPL-Caltech

Scientists using data from NASA's Wide-field Infrared Survey Explorer (WISE) have discovered the coldest class of star-like bodies, with temperatures as cool as the human body.

Astronomers hunted these dark orbs, termed Y dwarfs, for more than a decade without success. When viewed with a visible-light telescope, they are nearly impossible to see. WISE's infrared vision allowed the telescope to finally spot the faint glow of six Y dwarfs relatively close to our sun, within a distance of about 40 light-years. (read more)

Source: Universe Today/John Voisey

The general picture of star formation envisions stars emerging in clusters, having condensed from cores of gas under self gravity after having passed a critical density threshold. Perhaps the cloud was pushed over the threshold by the shockwave of a supernova or the tidal twisting of a nearby object. How it happens isn’t important since the methods are likely to be many and diverse. What is important is understanding what that threshold is so we may know when it is reached. It is generally referred to as the Jeans mass and observations have generally been well in line with densities predicted by this formulation. However, over the past several years, astronomers have discovered some objects amongst a a new class that form in regions and densities not readily explained by the Jeans mass criterion.

A new class of objects has been established that are now being called Very Low Luminosity Objects or VeLLOs. Among these, L1148-IRS has been an oddity. While still low in overall light output, this object was relatively bright in the infrared when compared to other VeLLOs. Studies of the object and its surrounding gas suggested that the object was forming in an unusually empty region, one in which the usual scenario doesn’t seem to fit. A new paper by the original discoverers of this object, suggest that there may be some peculiarities that may be related to this puzzle. (read more)

Original paper:
arXiv1106.2545v

Source: ESO Science Release eso1117

Star-forming region around the Tarantula Nebula in the Large Magellanic Cloud.
Image credit: ESO/M.-R. Cioni/VISTA Magellanic Cloud survey.
ESO's Acknowledgment: Cambridge Astronomical Survey Unit

An extraordinarily bright isolated star has been found in a nearby galaxy — the star is three million times brighter than the Sun. All previous similar “superstars” were found in star clusters, but this brilliant beacon shines in solitary splendour. The origin of this star is mysterious: did it form in isolation or was it ejected from a cluster? Either option challenges astronomers’ understanding of star formation.(read more)

Source: Kepler@NASA

NGC6811. Image credit: Anthony Ayiomamitis.

For many movie stars, their age is a well-kept secret. In space, the same is true of the actual stars. Like our Sun, most stars look almost the same for most of their lives. So how can we tell if a star is one billion or 10 billion years old? Astronomers may have found a solution – measuring the star’s spin.(read more)

Source: ESA/Hubble Photo Release heic1109

Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration

Hubble’s newest camera has taken an image of galaxy NGC 4214. This galaxy glows brightly with young stars and gas clouds, and is an ideal laboratory to research star formation and evolution. (read more)

Source: ESO Photo Release eso1113

Image credit: ESO, Digitized Sky Survey 2 and Joe DePasquale

This image of the nebula NGC 3582, which was captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile, shows giant loops of gas bearing a striking resemblance to solar prominences. These loops are thought to have been ejected by dying stars, but new stars are also being born within this stellar nursery. These energetic youngsters emit intense ultraviolet radiation that makes the gas in the nebula glow, producing the fiery display shown here.(read more)

Source: ESO Photo Release eso1109

A new image from ESO’s Very Large Telescope gives a close-up view of the dramatic effects new-born stars have on the gas and dust from which they formed. Although the stars themselves are not visible, material they have ejected is colliding with the surrounding gas and dust clouds and creating a surreal landscape of glowing arcs, blobs and streaks. (read more)

Source: ESO Photo Release eso1048

Globular cluster Messier 107, also known as NGC 6171, located about 21 000 light-years away in the constellation of Ophiuchus.
Image credit: ESO/ESO Imaging Survey

About 150 of the rich collections of old stars called globular clusters are known to orbit our galaxy, the Milky Way. This sharp new image of Messier 107, captured by the Wide Field Imager on the 2.2-meter telescope at ESO’s La Silla Observatory in Chile, displays the structure of one such globular cluster in exquisite detail. Studying these stellar swarms has revealed much about the history of our galaxy and how stars evolve. (read more)

Source: HubbleSite News Release STScI-2010-38

A galaxy thought to be over the hill is apparently still hard at work creating baby stars, a new study finds. Elliptical galaxies were once thought to be aging star cities whose star-making heyday was billions of years ago. But new observations with NASA's Hubble Space Telescope are helping to show that elliptical galaxies still have some youthful vigor left, thanks to encounters with smaller galaxies.

Hubble photo of the elliptical galaxy NGC 4150, once thought to be over the hill, but now revealed to be still forming new stars. Credit: NASA, ESA, R.M. Crockett (University of Oxford, U.K.), S. Kaviraj (Imperial College London and University of Oxford, U.K.), J. Silk (University of Oxford), M. Mutchler (Space Telescope Science Institute, Baltimore), R. O'Connell (University of Virginia, Charlottesville), and the WFC3 Scientific Oversight Committee.

Photos taken by the Hubble Space Telescope show the core of an elliptical galaxy known as NGC 4150,  which was thought to be beyond its fertile years for star formation, awash in streamers of dust, gas and clumps of young, blue stars that are significantly less than 1 billion years old. (read more)

Source: Harvard-Smithsonian Center for Astrophysics - Press Release 2010-26

The biggest galaxies in the universe are elliptical galaxies like the one in this artist's conception.
Image credit: David A. Aguilar (CfA)

The biggest galaxies in the universe are elliptical galaxies. The largest of these hold over one trillion stars according to astronomical census takers, compared to 400 billion in our Milky Way. However, new research shows that elliptical galaxies actually hold five to ten times as many stars as previously believed. This means that the total number of stars in the universe is likely three times bigger than realized.(read more)

The hidden stars are known as red dwarfs for their color and small size. Because red dwarfs are small and dim compared to stars like the Sun, astronomers hadn't been able to detect them in galaxies beyond the Milky Way before now. As such, they didn't know how many stars in the universe were red dwarfs.

Scientists used powerful instruments on the Keck Observatory in Hawaii to detect the faint signature of red dwarfs in the cores of eight elliptical galaxies, which are located between about 50 million and 300 million light-years away. They discovered that the red dwarfs, which are only between 10 and 30 percent as massive as the Sun, were much more bountiful than expected.

"As it turns out, the universe thinks small, at least when it comes to star size," said Harvard astronomer Charlie Conroy. "Our stellar inventory has changed dramatically."

"No one knew how many of these stars there were," said Pieter van Dokkum, a Yale University astronomer who led the research. "Different theoretical models predicted a wide range of possibilities, so this answers a long-standing question about just how abundant these stars are."

Their results imply that stellar population counts depend on what type of galaxy astronomers examine, just as a census of the city of New York and the town of Derby, Kansas will find very different population numbers.

"We usually assume other galaxies look like our own. But this suggests other conditions are possible in other galaxies," Conroy stated. "This discovery could have a major impact on our understanding of galaxy formation and evolution."

In particular, galaxies might contain less dark matter - a mysterious substance only detectable due to its gravitational effects - than previous measurements of their masses indicated. Instead, the abundant red dwarfs might contribute more mass than previously calculated.

Their findings appear in the Dec. 1st online issue of the journal Nature.

Source: ESO Science Release eso1046

Artist’s impression of the remarkable double star OGLE-LMC-CEP0227.
Image credit: ESO/L. Calçada

By discovering the first double star where a pulsating Cepheid variable and another star pass in front of one another, an international team of astronomers has solved a decades-old mystery. The rare alignment of the orbits of the two stars in the double star system has allowed a measurement of the Cepheid mass with unprecedented accuracy. Up to now astronomers had two incompatible theoretical predictions of Cepheid masses. The new result shows that the prediction from stellar pulsation theory is spot on, while the prediction from stellar evolution theory is at odds with the new observations. (read more)