This image was taken by the MUSE instrument, mounted on ESO’s Very Large Telescope and shows the region R44 within the Carina Nebula, 7500 light-years away. The massive stars within the star formation region slowly destroy the pillars of dust and gas from which they are born. [Larger versions]Spectacular new observations of vast pillar-like structures within the Carina Nebula have been made using the MUSE instrument on ESO’s Very Large Telescope. The different pillars analysed by an international team seem to be pillars of destruction — in contrast to the name of the iconic Pillars of Creation in the Eagle Nebula, which are of similar nature.
3D animation of the Carina Nebula. Credit: ESO/M. Kornmesser
The spires and pillars in the new images of the Carina Nebula are vast clouds of dust and gas within a hub of star formation about 7500 light-years away. The pillars in the nebula were observed by a team led by Anna McLeod, a PhD student at ESO, using the MUSE instrument on ESO’s Very Large Telescope.
This image was taken by the MUSE instrument, mounted on ESO’s Very Large Telescope and shows the region R18 within the Carina Nebula, 7500 light-years away. The massive stars within the star formation region slowly destroy the pillars of dust and gas from which they are born. [Larger images]The great power of MUSE is that it creates thousands of images of the nebula at the same time, each at a different wavelength of light. This allows astronomers to map out the chemical and physical properties of the material at different points in the nebula.
Images of similar structures, the famous Pillars of Creation[1] in the Eagle Nebula and formations in NGC 3603, were combined with the ones displayed here. In total ten pillars have been observed, and in so doing a clear link was observed between the radiation emitted by nearby massive stars and the features of the pillars themselves.
This image was taken by the MUSE instrument, mounted on ESO’s Very Large Telescope and shows the region R45 within the Carina Nebula, 7500 light-years away. The massive stars within the star formation region slowly destroy the pillars of dust and gas from which they are born. [Larger images]In an ironic twist, one of the first consequences of the formation of a massive star is that it starts to destroy the cloud from which it was born. The idea that massive stars will have a considerable effect on their surroundings is not new: such stars are known to blast out vast quantities of powerful, ionising radiation — emission with enough energy to strip atoms of their orbiting electrons. However, it is very difficult to obtain observational evidence of the interplay between such stars and their surroundings.
The team analysed the effect of this energetic radiation on the pillars: a process known as photoevaporation, when gas is ionised and then disperses away. By observing the results of photoevaporation — which included the loss of mass from the pillars — they were able to deduce the culprits. There was a clear correlation between the amount of ionising radiation being emitted by nearby stars, and the dissipation of the pillars.
This craggy fantasy mountaintop enshrouded by wispy clouds looks like a bizarre landscape. But it is indeed a pillar of gas and dust, three light-years tall, which is being eaten away by the brilliant light from nearby bright stars. The pillar is also being assaulted from within, as infant stars buried inside it fire off jets of gas that can be seen streaming from towering peaks. [Larger images]This might seem like a cosmic calamity, with massive stars turning on their own creators. However the complexities of the feedback mechanisms between the stars and the pillars are poorly understood. These pillars might look dense, but the clouds of dust and gas which make up nebulae are actually very diffuse. It is possible that the radiation and stellar winds from massive stars actually help create denser spots within the pillars, which can then form stars.
These breathtaking celestial structures have more to tell us, and MUSE is an ideal instrument to probe them with.
This zoom sequence starts with a broad view of the Milky Way and closes in on the Carina Nebula, an active stellar nursery about 7500 light-years from Earth. In the final sequence we see a new image taken with the VLT Survey Telescope at ESO’s Paranal Observatory. This picture was taken with the help of Sebastián Piñera, President of Chile, during his visit to the observatory on 5 June 2012 and released on the occasion of the telescope’s inauguration in Naples on 6 December 2012.
Credit: ESO/Nick Risinger (skysurvey.org)/Digitized Sky Survey 2 . Music: John Dyson (from the album Moonwind). Acknowledgement: VPHAS+ Consortium/Cambridge Astronomical Survey Unit
Notes
[1] The Pillars of Creation are an iconic image, taken with the NASA/ESA Hubble Space Telescope, making them the most famous of these structures. Also known as elephant trunks, they can be several light-years in length.
This mosaic shows 18 of the 19 quasars observed by an international team of astronomers, led by the ETH Zurich, Switzerland. Each observed quasar is surrounded by a bright gaseous halo. It is the first time that a survey of quasars shows such bright halos around all of the observed quasars. The discovery was made using the MUSE instrument at ESO’s Very Large Telescope. [Larger images]
An international team of astronomers has discovered glowing gas clouds surrounding distant quasars. This new survey by the MUSE instrument on ESO’s Very Large Telescope indicates that halos around quasars are far more common than expected. The properties of the halos in this surprising find are also in striking disagreement with currently accepted theories of galaxy formation in the early Universe.
The MUSE instrument on ESO’s Very Large Telescope is able to collect three-dimensional data. Using this data cube, astronomers were able to create a 3D representation of the gas halos surrounding the distant quasars. Credit: ESO/S. Cantalupo
An international collaboration of astronomers, led by a group at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland, has used the unrivalled observing power of MUSE on the Very Large Telescope (VLT) at ESO’s Paranal Observatory to study gas around distant active galaxies, less than two billion years after the Big Bang. These active galaxies, called quasars, contain supermassive black holes in their centres, which consume stars, gas, and other material at an extremely high rate. This, in turn, causes the galaxy centre to emit huge amounts of radiation, making quasars the most luminous and active objects in the Universe.
The study involved 19 quasars, selected from among the brightest that are observable with MUSE. Previous studies have shown that around 10% of all quasars examined were surrounded by halos, made from gas known as the intergalactic medium. These halos extend up to 300 000 light-years away from the centres of the quasars. This new study, however, has thrown up a surprise, with the detection of large halos around all 19 quasars observed — far more than the two halos that were expected statistically. The team suspects this is due to the vast increase in the observing power of MUSE over previous similar instruments, but further observations are needed to determine whether this is the case.
“It is still too early to say if this is due to our new observational technique or if there is something peculiar about the quasars in our sample. So there is still a lot to learn; we are just at the beginning of a new era of discoveries”, says lead author Elena Borisova, from the ETH Zurich.
The original goal of the study was to analyse the gaseous components of the Universe on the largest scales; a structure sometimes referred to as the cosmic web, in which quasars form bright nodes [1]. The gaseous components of this web are normally extremely difficult to detect, so the illuminated halos of gas surrounding the quasars deliver an almost unique opportunity to study the gas within this large-scale cosmic structure.
This mosaic shows 18 of the 19 quasars observed by an international team of astronomers, led by the ETH Zurich, Switzerland. Each observed quasar is surrounded by a bright gaseous halo. It is the first time that a survey of quasars shows such bright halos around all of the observed quasars. The discovery was made using the MUSE instrument at ESO’s Very Large Telescope. Credit: ESO/Borisova et al.
The 19 newly-detected halos also revealed another surprise: they consist of relatively cold intergalactic gas — approximately 10 000 degrees Celsius. This revelation is in strong disagreement with currently accepted models of the structure and formation of galaxies, which suggest that gas in such close proximity to galaxies should have temperatures upwards of a million degrees.
It is the first time that MUSE and its unique observing capabilities have been used for a survey of this kind. The discovery shows the potential of the instrument for observing this type of object [2]. Co-author Sebastiano Cantalupo is very excited about the new instrument and the opportunities it provides:
“We have exploited the unique capabilities of MUSE in this study, which will pave the way for future surveys. Combined with a new generation of theoretical and numerical models, this approach will continue to provide a new window on cosmic structure formation and galaxy evolution.”
Notes
[1] The cosmic web is the structure of the Universe at the largest scale. It is comprised of spindly filaments of primordial material (mostly hydrogen and helium gas) and dark matter which connect galaxies and span the chasms between them. The material in this web can feed along the filaments into galaxies and drive their growth and evolution.
[2] MUSE is an integral field spectrograph and combines spectrographic and imaging capabilities. It can observe large astronomical objects in their entirety in one go, and for each pixel measure the intensity of the light as a function of its colour, or wavelength.
Via a NASA-led citizen science project, eight people with no formal training in astrophysics helped discover what could be a fruitful new place to search for planets outside our solar system – a large disk of gas and dust encircling a star known as a circumstellar disk.
Artist’s concept of the newly discovered disk. Credits: Jonathan Holden
A paper, published in The Astrophysical Journal Letters and coauthored by eight citizen scientists involved in the discovery, describes a newly identified red dwarf star, AWI0005x3s, and its warm circumstellar disk, the kind associated with young planetary systems. Most of the exoplanets, which are planets outside our solar system, that have been imaged to date dwell in disks similar to the one around AWI0005x3s.
The disk and its star are located in what is dubbed the Carina association – a large, loose grouping of similar stars in the Carina Nebula approximately 212 light years from our sun. Its relative proximity to Earth will make it easier to conduct follow-on studies.
“Most disks of this kind fade away in less than 30 million years,” said Steven Silverberg, a graduate student at Oklahoma University and lead author of the paper. “This particular red dwarf is a candidate member of the Carina association, which would make it around 45 million years old. It’s the oldest red dwarf system with a disk we’ve seen in one of these associations.”
Since the launch of NASA’s Disk Detective website in January 2014, approximately 30,000 citizen scientists have performed roughly two million classifications of stellar objects, including those that led to this discovery. Through Disk Detective, citizen scientists study data from NASA’s Wide-field Infrared Survey Explorer mission (WISE), the agency’s Two-Micron All Sky Survey project, and other stellar surveys.
“Without the help of the citizen scientists examining these objects and finding the good ones, we might never have spotted this object,” said Marc Kuchner, an astrophysicist at NASA’s Goddard Space Fight Center in Greenbelt, Maryland, who leads Disk Detective. “The WISE mission alone found 747 million objects, of which we expect a few thousand to be circumstellar disks.”
The eight citizen scientist co-authors, members of an advanced user group, volunteered to help by researching disk candidates. Their data led to the discovery of this new disk.
“I’ve loved astronomy since childhood and wanted to be part of the space program, as did every boy my age,” adds Milton Bosch, a citizen scientist co-author from California. “I feel very fortunate to be part of such a great group of dedicated people, and am thrilled to partake in this adventure of discovery and be a co-author on this paper.”
Disk Detective is a collaboration between NASA, Zooniverse, the University of Oklahoma, University of Córdoba in Argentina, National Astronomical Observatory of Japan, Space Telescope Science Institute, Harvard-Smithsonian Center for Astrophysics, Carnegie Institution of Washington, University of Hawaii and Korea Astronomy and Space Science Institute.
To learn more about opportunities for the public to participate in NASA science and technology projects, visit: www.nasa.gov/solve
This mosaic shows the Carina Nebula (left part of the image), home of the Eta Carinae star system. This part was observed with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory. The middle part shows the direct surrounding of the star: the Homunculus Nebula, created by the ejected material from the Eta Carinae system. This image was taken with the NACO near-infrared adaptive optics instrument on ESO’s Very Large Telescope. The right image shows the innermost part of the system as seen with the Very Large Telescope Interferometer (VLTI). It is the highest resolution image of Eta Carinae ever. [Larger images.]An international team of astronomers have used the Very Large Telescope Interferometer to image the Eta Carinae star system in the greatest detail ever achieved. They found new and unexpected structures within the binary system, including in the area between the two stars where extremely high velocity stellar winds are colliding. These new insights into this enigmatic star system could lead to a better understanding of the evolution of very massive stars.
This image represent the best image of the Eta Carinae star system ever made. The observations were made with the Very Large Telescope Interferometer and could lead to a better understanding of the evolution of very massive stars. [Larger images]
This animation zooms in on the massive star system Eta Carinae, located in the Carina Nebula. During the zoom the Homunculus Nebula and finally the violent surrounding of Eta Carinae becomes visible.
This colossal binary system consists of two massive stars orbiting each other and is very active, producing stellar winds which travel at velocities of up to ten million kilometres per hour [1]. The zone between the two stars where the winds from each collide is very turbulent, but until now it could not be studied.
This image is a colour composite made from exposures from the Digitized Sky Survey 2 (DSS2). The field of view is approximately 4.7 x 4.9 degrees. [Larger images.]
The power of the Eta Carinae binary pair creates dramatic phenomena. A “Great Eruption” in the system was observed by astronomers in the 1830s. We now know that this was caused by the larger star of the pair expelling huge amounts of gas and dust in a short amount of time, which led to the distinctive lobes, known as the Homunculus Nebula, that we see in the system today. The combined effect of the two stellar winds as they smash into each other at extreme speeds is to create temperatures of millions of degrees and intense deluges of X-ray radiation.
This animation zooms from outside the Homunculus Nebula, which Eta Carinae ejected in a famous outburst in the 19th century, to the system’s two massive orbiting stars. Credit: NASA Goddard CI Lab
The central area where the winds collide is so comparatively tiny — a thousand times smaller than the Homunculus Nebula — that telescopes in space and on the ground so far have not been able to image them in detail. The team has now utilised the powerful resolving ability of the VLTI instrument AMBER to peer into this violent realm for the first time. A clever combination — an interferometer — of three of the four Auxiliary Telescopes at the VLT lead to a tenfold increase in resolving power in comparison to a single VLT Unit Telescope. This delivered the sharpest ever image of the system and yielded unexpected results about its internal structures.
This new image of the luminous blue variable Eta Carinae was taken with the NACO near-infrared adaptive optics instrument on ESO’s Very Large Telescope, yielding an incredible amount of detail. The images clearly shows a bipolar structure as well as the jets coming out from the central star. The image was obtained by the Paranal Science team and processed by Yuri Beletsky (ESO) and Hännes Heyer (ESO). It is based on data obtained through broad (J, H, and K; 90 second exposure time per filters) and narrow-bands (1.64, 2.12, and 2.17 microns; probing iron, molecular and atomic hydrogen, respectively; 4 min per filter). [Larger images.]
The new VLTI image clearly depict the structure which exists between the two Eta Carinae-stars. An unexpected fan-shaped structure was observed where the raging wind from the smaller, hotter star crashes into the denser wind from the larger of the pair.
“Our dreams came true, because we can now get extremely sharp images in the infrared. The VLTI provides us with a unique opportunity to improve our physical understanding of Eta Carinae and many other key objects”, says Gerd Weigelt.
In addition to the imaging, the spectral observations of the collision zone made it possible to measure the velocities of the intense stellar winds [2]. Using these velocities, the team of astronomers were able to produce more accurate computer models of the internal structure of this fascinating stellar system, which will help increase our understanding of how these kind of extremely high mass stars lose mass as they evolve.
This spectacular panoramic view combines a new image of the field around the Wolf–Rayet star WR 22 in the Carina Nebula (right) with an earlier picture of the region around the unique star Eta Carinae in the heart of the nebula (left). The picture was created from images taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. This image is available as a mounted image in the ESOshop. [Larger image]
Team member Dieter Schertl (MPIfR) looks forward:
“The new VLTI instruments GRAVITY and MATISSE will allow us to get interferometric images with even higher precision and over a wider wavelength range. This wide wavelength range is needed to derive the physical properties of many astronomical objects.”
Notes
[1] The two stars are so massive and bright that the radiation they produce rips off their surfaces and spews them into space. This expulsion of stellar material is referred to as stellar “wind”, and it can travel at millions of kilometres per hour.
[2] Measurements were done through the Doppler effect. Astronomers use the Doppler effect (or shifts) to calculate precisely how fast stars and other astronomical objects move toward or away from Earth. The movement of an object towards or away from us causes a slight shift in its spectral lines. The velocity of the motion can be calculated from this shift.
