News from Herschel and Planck
- Largest Space Telescope Ever Closes its Eyes on the Universe
- Herschel Space Observatory to finish observing soon
- Herschel Space Observatory spots comet massacre around nearby star
- A New View of Centaurus A
- Watery Star Births
- The Herschel Space Observatory Hones in on our Galactic Neighbours and Spies on a Comet
- Updates for the Herschel and Planck missions
March 6, 2013
Herschel Space Observatory to finish observing soon
The European Space Agency (ESA) has announced that the Herschel Space Observatory is expected to exhaust its supply of liquid helium coolant in the coming weeks after spending more than three exciting years studying the cool Universe.
With funding from the Canadian Space Agency (CSA), two teams of Canadian astronomers are part of the Herschel mission, and participated in the development and operations of two of the telescope's three science instruments: the Heterodyne Instrument for the Far Infrared (HIFI) and the Spectral and Photometric Imaging Receiver (SPIRE). Professor Michel Fich of the University of Waterloo is the Principal Investigator for HIFI in Canada. Professor David Naylor of the University of Lethbridge is the Principal Investigator for Canada's contribution to SPIRE.
The largest, most powerful infrared telescope ever flown in space, Herschel has made extraordinary discoveries across a wide range of topics, from starburst galaxies in the distant Universe to newly forming planetary systems orbiting nearby young stars. Herschel's pioneering mission is the first to cover the entire wavelength range from the far-infrared to submillimetre, making it possible to study previously invisible cool regions of gas and dust in the cosmos, and providing new insights into the origin and evolution of stars and galaxies.
In order to make such sensitive far-infrared observations, the detectors of the three science instruments must be cooled to a frigid –271°C (close to absolute zero) using superfluid liquid helium. When it was launched on May 14, 2009, Herschel was equipped with enough helium for 3.5 years of operations. Since helium evaporates over time, engineers believe that almost all of the liquid helium has now gone. While it is not possible to predict the exact day the helium will finally run out soon.
The science observing program was carefully planned to take full advantage of every last drop of helium, with all of the highest-priority observations already completed.
"When observing comes to an end, we expect to have performed over 22 000 hours of science observations, 10% more than we had originally planned, so the mission has already exceeded expectations," says Leo Metcalfe, the Herschel Science Operations and Mission Manager at ESA's European Space Astronomy Centre in Madrid, Spain.
Herschel will continue communicating with its ground stations for some time after the helium is exhausted, allowing a range of technical tests. Finally, in early May, it will be propelled into its long-term stable parking orbit around the Sun. The science team will continue to analyze Herschel's data for years to come. Canadian astronomers will play a leading role in this analysis for both HIFI and SPIRE.
With material courtesy of the ESA
April 17, 2012
Herschel Space Observatory spots comet massacre around nearby star
An international team of astronomers—including Canadians from the University of Lethbridge and the National Research Council Canada—using the ESA's Herschel Space Observatory have discovered that the dust belt around the nearby star Fomalhaut appears to be formed from dust resulting from collisions that can destroy up to thousands of icy comets every day.
Fomalhaut is a young star, just a few hundred million years old, and twice as massive as the Sun. Its dust belt was discovered in the 1980s but Herschel's new images show it in much more detail than ever before.
Bram Acke, at the University of Leuven in Belgium, and colleagues analysed the Herschel observations and found the dust temperatures in the belt to be between –230ºC and –170ºC. However, because Fomalhaut is slightly off-centre and closer to the southern side of the belt, the southern side is warmer and brighter than the northern side.
Both the narrowness and asymmetry of the belt are thought to be due to the gravity of a possible planet in orbit around the star, as suggested by earlier Hubble Space Telescope images.
The Herschel data show that the dust in the belt has the thermal properties of small solid particles, with sizes of only a few millionths of a metre across.
But this created a paradox because the Hubble Space Telescope observations suggested solid grains more than ten times larger.
Those observations collected starlight scattering off the grains in the belt and showed it to be very faint at Hubble's visible wavelengths, suggesting that the dust particles are relatively large. But that appears to be incompatible with the temperature of the belt as measured by Herschel in the far-infrared.
To resolve the paradox, Dr. Acke and colleagues suggest that the dust grains must be large fluffy aggregates, similar to dust particles released from comets in our own Solar System.
These would have both the correct thermal and scattering properties. However, this leads to another problem.
The bright starlight from Fomalhaut should blow small dust particles out of the belt very rapidly, yet such grains appear to remain abundant there.
The only way to overcome this contradiction is to resupply the belt through continuous collisions between larger objects in orbit around Fomalhaut, creating new dust.
To sustain the belt, the rate of collisions must be impressive: each day, the equivalent of either two 10 km-sized comets or 2000 1 km-sized comets must be completely crushed into small fluffy, dust particles.
"I was really surprised," says Dr. Acke, "To me this was an extremely large number."
To keep the collision rate so high, there must be between 260 billion and 83 trillion comets in the belt, depending on their size. Our own Solar System has a similar number of comets in its Oort Cloud, which formed from objects scattered from a disc surrounding the Sun when it was as young as Fomalhaut.
The Herschel images of Fomalhaut are spectacular and the apparent contradiction between the Hubble and Herschel measurements shows the importance of complementary observations and how, when combined, they lead to a deeper understanding of the universe," says Professor David Naylor of the University of Lethbridge, Principal Investigator for Canada's contribution to SPIRE, one of the two instruments that produced led to this discovery.
The Canadian Herschel SPIRE team includes scientists from the universities of British Columbia, Toronto, Victoria, McMaster University and the National Research Council Canada. Blue Sky Spectroscopy, Lethbridge, Alberta, hosts the centre of expertise for the SPIRE imaging spectrometer.
SPIRE has been developed by a consortium of institutes led by Cardiff Univ. (UK) and including: Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK); and NASA (USA).
PACS, the other instrument that contributed to this discovery, was developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KUL, CSL, IMEC (Belgium); CEA, OAMP (France); MPIA (Germany); IFSI, OAP/AOT, OAA/CAISMI, LENS, SISSA (Italy); IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESAPRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI (Italy), and CICT/MCT (Spain).
With material courtesy of the ESA
April 17, 2012
A New View of Centaurus A
Look closely at this eye-popping image of Centaurus A (also known as NGC 5128). Located 12 million light years away, this giant elliptical galaxy has a halo of stars surrounding it, with powerful jets of high-energy particles streaming out from its core, where a supermassive black hole eats matter at stunning rates. Until recently, the prominent dark lane that crosses the galaxy has hidden the very centre of the galaxy from Earth-based telescopes. That is, until now.
This image is actually a composite containing data from four different science instruments on three separate telescopes, two of which are based in space. By harnessing the power of the space-based observatories, astronomers—including Dr. Christine Wilson from McMaster University—were able to peer past the dark lane in Centaurus A and see what lies beyond.
The colours of the image are actually formed from four different wavelengths: X-rays shown up as cyan, blue and purple (in order of increasing energy); far-infrared light appears yellow; sub-millimetre is red; and the visible waveband, which is what our eyes can discern, is white. The X-ray data was obtained with the EPIC camera on board ESA's XMM-Newton X-ray Observatory; the far-infrared and sub-millimetre data were obtained with the PACS and SPIRE instruments on board the Herschel Space Observatory; the visible waveband image was obtained with the MPG/ESO 2.2-metre Telescope at La Silla Observatory, Chile.
By looking at an object in many different wavelengths, astronomers gain a comprehensive view of how the various components of this fascinating galaxy interact with one another on different scales. For example, the data from the PACS instrument on board Herschel revealed the structure of the galaxy's disc by detecting the glow of cold dust within it.
October 22, 2010
Watery Star Births
Herschel Space Telescope finds stellar nursery awash with water
Like in any good detective story, astronomers are piecing together clues to a cosmic mystery surrounding the most precious of molecules in the Universe—water. A team of Canadian science sleuths part of the ESA's Herschel Space Telescope mission have found the most detailed evidence of abundant water in a distant star factory. This exciting new discovery may not only reveal secrets behind the birth of stars but may even provide tantalizing hints to the possible origin of water in the solar system.
With support from the CSA, Canadian astronomers are using high-flying Herschel's exquisitely sensitive water-sniffing instrument called HiFi (Heterodyne Instrument for the Far Infrared), part of which was built in Ontario, to hunt down the spectral fingerprints of water lurking around newborn stars.
"We didn't actually expect to see much in our very first observations, but Herschel has given us truly spectacular results," says Michael Fich, astronomy professor at University of Waterloo and Canadian Principal Investigator for Herschel's HiFi science instrument. "We knew that water plays a vital role in star-forming regions but have never been able to get a detailed picture of what is going on until now."
They hit the jackpot with their first target, a protostar in a molecular cloud called NGC 7129 located 3300 light-years from Earth in the constellation Cepheus. The star turns out to be much hotter than ever thought, with temperatures of 1500 degrees Kelvin. Capturing it only a few thousand years after its birth, astronomers think this bizarre star breaks the record as the youngest and most active intermediate newborn ever observed.
Astronomers understand a lot about how low mass, sun-like stars are produced but they don't know much about these larger siblings, like how they are formed and if they regularly create planets around them. Water has been theorized to play a key role in star forming clouds.
The HiFi science team is also attempting to understand what role water may play in the birth of exoplanets. Can all this water in the surrounding cloud be transported into the planet-forming nursery around the newborn stars?
"We know that cosmic water vapor freezes onto dust inside cold, dark molecular clouds. These ice coated dust grains may come together and form planets and comets, and maybe even ultimately the atmospheres of planets." says Doug Johnstone, professor of astronomy at University of Victoria and HiFi science team member. "Understanding water in molecular clouds is fundamentally important in our understanding of the universe," says Johnstone. "It shouldn't be all that surprising H20 is so near and dear to us since it is the stuff out of which planets and even people are made."
December 1, 2009
The Herschel Space Observatory Hones in on our Galactic Neighbours and Spies on a Comet
Unprecedented images bring familiar objects into focus
A series of images from the Herschel Space Observatory is providing scientists with new perspectives of some well known astronomical targets. Herschel has beamed back exceptionally good astronomical fingerprints (spectra) of a broad range of objects (from comets, to massive stars, star-forming regions and a variety of galaxies), including new evidence for water and the building blocks of life in the Universe.
Messier 82-A Starburst Galaxy in the Big Dipper (Ursa major)
This mosaic shows some of the early data and images acquired by Herschel's SPIRE instrument during its testing phase.
SPIRE captured these images of Messier objects 81 (M81) and 82 (M82), a pair of galaxies located in Ursa major (which contains the familiar asterism, the Big Dipper). As the spectrum suggests, SPIRE detected a strong presence of carbon monoxide in M82 (left), as well as atomic carbon and ionized nitrogen.
M82 is the nearest starburst galaxy to Earth (a mere 12 million light years away). The intense star formation in M82 has been triggered by the gravitational tidal forces caused by its close passage by its more massive neighbour, M81.
SPIRE is one of the two Herschel instruments in which Canadian scientists play a role. Astronomer Christine Wilson from McMaster University is the principal researcher on the Herschel project "Physical Processes in the Interstellar Medium of Very Nearby Galaxies" that produced this image. Led by Wilson, this group of scientists is examining the closest examples of every type of galaxy they can find to study the properties of the gases in galaxies and determine how gases relate to star formation.
Galactic Star Formation in the Orion Nebula (Orion Bar-DR21)
This SPIRE spectrum reveals exciting new clues about a star-forming region of the famous Orion nebula known as the Orion Bar. SPIRE made the first-ever detection at long wavelengths of an ion known as methylidynium, a key constituent for larger carbon-bearing molecules, such as organic molecules-the building blocks of life. By measuring the heights of the spikes on the left side of the chart, astronomers are able to estimate the temperature and density of interstellar gas in this region.
Water on Comet Garradd
The peak in the above spectrum, produced by Herschel's HIFI (Heterodyne Instrument for the Far Infrared) instrument, confirms the presence of water on Comet Garradd. Some of the studies done with HIFI will compare the characteristics of water and volatile organic molecules released by different comets in the Solar System as they approach the Sun.
Comets are essentially amalgamations of small dust grains held together by ice—like dirty snowballs. They were formed some 4.5 billion years ago in cold, outer regions of the Solar system. For most of their history, comets dwell far from the Sun, and therefore represent a pristine record of the early conditions when the Solar System and the planets were formed. Scientists believe that comets may have contributed greatly to water on the Earth and other terrestrial planets. Small perturbations in their orbit can propel comets inwards. When they approach the Sun, the increased heat sublimates the ice releasing water and other molecules into the vapour phase; this means that the composition and characteristics of the comet can be easily measured.
The Herschel Space Observatory was launched on May 14, 2009 on board the same Ariane 5 rocket that was carrying the Planck Space Telescope. With funding from the CSA, several Canadian institutions and entrepreneurs contributed to Herschel by taking part in the development of two of the three science instruments: the Heterodyne Instrument for the Far Infrared (HIFI) and the Spectral and Photometric Imaging Receiver (SPIRE).
Professor Michel Fich of the University of Waterloo is the Principal Investigator for HIFI in Canada. COM DEV, Cambridge, Ontario, is the prime contractor for Canada's contribution to HIFI.
Professor David Naylor of the University of Lethbridge is the Principal Investigator for Canada's contribution to SPIRE through ISIS, the Institute for Space Imaging Science (which also includes the University of Calgary and Athabaska University). Blue Sky Spectroscopy, Lethbridge, Alberta, hosts the centre of expertise for the SPIRE imaging spectrometer and is responsible for processing the spectral data shown in the figures.
The Canadian Herschel team includes scientists from the universities of British Columbia, Calgary, Western Ontario, Toronto, Victoria, McMaster University and the National Research Council Canada.
July 10, 2009
Updates for the Herschel and Planck missions
The ESA announced that the Herschel Space Observatory has begun producing data and is performing far beyond expectations. Herschel was launched simultaneously with the Planck Space Telescope on May 14, 2009.
To date, Herschel's three instruments (the Heterodyne Instrument for the Far Infrared (HIFI), the Spectral and Photometric Imaging Receiver (SPIRE) and the Photometric Array Camera and Spectrometer (PACS)) were tested on a few astronomical targets before their initial calibration had even begun. Their first results have already surpassed data gathered by previous missions. Herschel's goal is to probe the Universe at far infrared and sub-millimetre wavelengths to determine how stars, planets and galaxies form and evolve.
Planck's instruments (the Low Frequency Instrument (LFI) and the High Frequency Instrument (HFI)) are being calibrated and optimized. They are nearly ready to observe the sky full-time. Planck's planned mission is to complete two surveys of the entire sky to map the microwave background radiation - the remnants from the Big Bang.
Herschel and Planck's ultra-precise science instruments were developed by an international consortium, including several Canadian teams.
Professor Michel Fich of the University of Waterloo is the Principal Investigator for Herschel-HIFI in Canada. COM DEV, Cambridge, Ontario, is the prime contractor for Canada's contribution to HIFI.
Professor David Naylor of the University of Lethbridge is the Principal Investigator for Canada's contribution to Herschel-SPIRE. Blue Sky Spectroscopy, Lethbridge, Alberta, hosts a centre of expertise for the SPIRE Imaging Fourier Transform Spectrometer. The Canadian Herschel team includes scientists from the universities of British Columbia, Calgary, Western Ontario, Toronto, Victoria, McMaster University and the National Research Council Canada.
Professor Douglas Scott of the University of British Columbia is leading the Canadian Planck-LFI team. The Planck-HFI team is led by Professor J. Richard Bond of the University of Toronto.
The Canadian teams have spent more than a decade working with their international colleagues to plan for the Herschel and Planck missions, and will be directly involved in using the data to answer some of the most fundamental astronomical questions about the Universe.
For more information about Canada's role in the Herschel and Planck missions visit the: www.asc-csa.gc.ca/eng/satellites/herschel/default.asp and www.asc-csa.gc.ca/eng/satellites/planck.asp
For details about Herschel's first discoveries, visit: www.esa.int/esaCP/SEMAYT6CTWF_index_0.html
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