Sharpest View Ever of Dusty Disc Around Aging Star

ESO - European Southern Observatory logo.

9 March 2016

VLTI finds discs around aging stars similar to those around young ones

The dusty ring around the aging double star IRAS 08544-4431

The Very Large Telescope Interferometer at ESO’s Paranal Observatory in Chile has obtained the sharpest view ever of the dusty disc around an aging star. For the first time such features can be compared to those around young stars — and they look surprisingly similar. It is even possible that a disc appearing at the end of a star’s life might also create a second generation of planets.

As they approach the ends of their lives many stars develop stable discs of gas and dust around them. This material was ejected by stellar winds, whilst the star was passing through the red giant stage of its evolution. These discs resemble those that form planets around young stars. But up to now astronomers have not been able to compare the two types, formed at the beginning and the end of the stellar life cycle.

The dusty ring around the aging double star IRAS 08544-4431

Although there are many discs associated with young stars that are sufficiently near to us to be studied in depth, there are no corresponding old stars with discs that are close enough for us to obtain detailed images.

But this has now changed. A team of astronomers led by Michel Hillen and Hans Van Winckel from the Instituut voor Sterrenkunde in Leuven, Belgium, has used the full power of the Very Large Telescope Interferometer (VLTI) at ESO’s Paranal Observatory in Chile, armed with the PIONIER instrument, and the newly upgraded RAPID detector.

Their target was the old double star IRAS 08544-4431 [1], lying about 4000 light-years from Earth in the southern constellation of Vela (The Sails). This double star consists of a red giant star, which expelled the material in the surrounding dusty disc, and a less-evolved more normal star orbiting close to it.

The aging double star IRAS 08544-4431 in the constellation of Vela (The Sails)

Jacques Kluska, team member from the University of Exeter, United Kingdom, explains: “By combining light from several telescopes of the Very Large Telescope Interferometer, we obtained an image of stunning sharpness — equivalent to what a telescope with a diameter of 150 metres would see. The resolution is so high that, for comparison, we could determine the size and shape of a one euro coin seen from a distance of two thousand kilometres.”

Thanks to the unprecedented sharpness of the images [2] from the Very Large Telescope Interferometer, and a new imaging technique that can remove the central stars from the image to reveal what lies around them, the team could dissect all the building blocks of the IRAS 08544-4431 system for the first time.

The rich celestial landscape around the aging double star IRAS 08544-4431

The most prominent feature of the image is the clearly resolved ring. The inner edge of the dust ring, seen for the first time in these observations, corresponds very well with the expected start of the dusty disc: closer to the stars, the dust would evaporate in the fierce radiation from the stars.

“We were also surprised to find a fainter glow that is probably coming from a small accretion disc around the companion star. We knew the star was double, but weren’t expecting to see the companion directly. It is really thanks to the jump in performance now provided by the new detector in PIONIER, that we are able to view the very inner regions of this distant system,” adds lead author Michel Hillen.

Zooming in on aging double star IRAS 08544-4431

The team finds that discs around old stars are indeed very similar to the planet-forming ones around young stars. Whether a second crop of planets can really form around these old stars is yet to be determined, but it is an intriguing possibility.

“Our observations and modelling open a new window to study the physics of these discs, as well as stellar evolution in double stars. For the first time the complex interactions between close binary systems and their dusty environments can now be resolved in space and time,” concludes Hans Van Winckel.

Notes:

[1] The name of the object indicates that it is a source of infrared radiation that was detected and catalogued by the IRAS satellite observatory in the 1980s.

[2] The resolution of the VLTI, used with the four Auxiliary Telescopes, was about one milliarcsecond (1/1000th of 1/3600th of a degree).

More information:

This research was presented in a paper entitled “Imaging the dust sublimation front of a circumbinary disk”, by M. Hillen et al., to appear as a letter in the journal Astronomy & Astrophysics.

The team is composed of M. Hillen (Instituut voor Sterrenkunde, Leuven, Belgium), J. Kluska (University of Exeter, Exeter, United Kingdom), J.-B. Le Bouquin (UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble, France), H. Van Winckel (Instituut voor Sterrenkunde, Leuven, Belgium), J.-P. Berger (ESO, Garching, Germany), D. Kamath (Instituut voor Sterrenkunde, Leuven, Belgium) and V. Bujarrabal (Observatorio Astronómico Nacional, Alcalá de Henares, Spain).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1608/eso1608a.pdf

Further information about PIONIER, and the new RAPID detector:
http://www.eso.org/public/teles-instr/vlt/vlt-instr/pionier/
http://www.eso.org/public/announcements/ann15042/

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

Related links:

Very Large Telescope Interferometer (VLTI): http://www.eso.org/public/teles-instr/technology/interferometry/

Instituut voor Sterrenkunde: https://fys.kuleuven.be/ster

PIONIER instrument: http://www.eso.org/public/teles-instr/vlt/vlt-instr/pionier/

RAPID detector: http://www.eso.org/public/announcements/ann15042/

IRAS 08544-4431: http://cdsweb.u-strasbg.fr/cgi-bin/bibobj?2009A%26A...505.1221V&IRAS+08544-4431

Images, Text, Credits: ESO/Digitized Sky Survey 2/Acknowledgement: Davide De Martin/IAU and Sky & Telescope/Video: ESO/Digitized Sky Survey 2/N. Risinger (skysurvey.org). Acknowledgement: Davide De Martin. Music: Johan B. Monell (www.johanmonell.com).

Best regards, Orbiter.ch

Ariane 5 launch contributes to Ariane 6 development

Arianespace - Ariane 5 / Flight VA229 Mission poster.


9 March 2016

Ariane 5 liftoff on VA229

An Ariane 5 lifted off this morning to deliver telecom satellite Eutelsat-65 West A into its planned transfer orbit. Liftoff of flight VA229 occurred at 05:20 GMT (02:20 local time, 06:20 CET) from Europe’s Spaceport in Kourou, French Guiana.

Eutelsat-65 West A was the sole passenger on this launch. With a mass of 6707 kg, it was released about 27 minutes into the mission.

Arianespace Flight VA229 - EUTELSAT 65 West A

Positioned at 65ºW in geostationary orbit, the satellite has a design life of 15 years and will provide coverage throughout Latin America and especially Brazil with video and direct-to-home broadcasting, as well as flexible high-speed broadband access.

Eutelsat-65 West Asatellite

After satellite separation, the propellants’ temperature and level were recorded to study its behaviour in the rocket’s upper stage under microgravity. This information will help to design the upper stage for Ariane 6.

Flight VA229 was the second Ariane 5 launch of the year and the 85th Ariane 5 mission.

For more information about Arianespace, visit: http://www.arianespace.com/

Images. Video, Text, Credits: ESA/Arianespace/EUTELSAT.

Best regards, Orbiter.ch

Marshall Supports 15 Years of International Space Station Discoveries

NASA patch.

March 8, 2016

In November 2000, NASA began a run of 15 years of continuous human presence in orbit on the International Space Station. Four months later, on March 8, 2001, a team of people at NASA's Marshall Space Flight Center in Huntsville, Alabama, began to leave their own mark on discovery by starting around-the-clock support of scientific activities on the orbiting laboratory from Marshall's Payload Operations Integration Center.

For 15 years, the payload operations center has been the science command post for the orbiting laboratory. Experts in disciplines including engineering, math, science, logistics, computer programming, and communications manage and monitor investigations on the space station around the clock, 365 days a year. Every day, they collaborate with astronauts and cosmonauts orbiting overhead and hundreds of scientists around the globe.

Image above: Three members of the original team who were on console when the Payload Operations Integration Center first began support of the station were photographed in March 2001. Through 15 years and a major modernization of the facility, they still work there -- from left, Payload Rack Officer Brian Little, Ground Training Integrator Ola Myszka, and Payload Rack Officer Aris Tanone. Image Credits: NASA/Fred Deaton.

"Time in space on the world’s most unique orbiting laboratory is precious,” said Chris Cianciola, manager for payload operations and integration in Marshall's Flight Programs and Partnerships Office. “Marshall’s team takes advantage of the latest technology and years of experience in space operations to squeeze the most science possible out of each and every space station experiment.”

Marshall has a long history of supporting science operations on both Skylab — America’s first space station and on the space shuttle and Spacelab missions lasting up to 2 weeks. For the space station, supporting science investigations became an all-day, everyday task. Planning that level of support and creating the control room to help run it all required a new way of thinking.

"We planned research for NASA's shuttle missions years in advance, but these missions were short," said Carmen Price, one of the first payload operations directors and now the payload operations manager in Marshall's Flight Programs and Partnerships Office. "To support space station science, we needed the same 24-hour-a-day support, but it had to be for 365 days a year — a lot longer than two weeks.”

To manage and schedule research, the team assigned investigations to a to six-month period designated as an expedition or increment. However, some research continues longer than six months and is scheduled over the course of many expeditions, while some investigations are only conducted while cargo vehicles are docked with the station. Breaking research into 6-month chunks and assigning people to support specific investigations and operations made it possible to conduct a variety of experiments from almost every scientific discipline with different research requirements and of varying lengths.

Today, space station research continues to accelerate. Research started on the station way before assembly was complete in 2011. In the early days, there were only about 40 investigations on board. As laboratories and research facilities were added, research increased. Today, the crew spends an average of 40 hours a week on station and conducts about 250 investigations every six months. In the last 15 years, the Marshall team has worked with 2,484 investigators and students from 83 countries to complete 1,765 investigations. When astronauts begin traveling to station on commercial crew vehicles in a few years, the amount of time dedicated to research on the station is expected to double.

International Space Station (ISS). Image Credit: NASA

This means more research and more work both before and during expeditions. The operations center's flight controllers not only help crew members conduct the experiments but even before an investigation is launched, they work with scientists and payload developers to design their experiments for efficient and successful operations. Once the research gets started on the station, controllers assist the crew, monitor all research facilities and even operate many while the space station crew is off duty or sleeping.

Many who have staffed those consoles in support of space station science have since moved on to other positions. But a few, including Indonesian native Aris Tanone, made a career of working with the space station crew.

In 1970, Tanone was in his first year at Gadjah Mada University in Yoyakarta, Indonesia, when he read an article about the space race and Wernher von Braun. At the time, it was just a dream to work in the space industry. Tanone made it a reality when -- 30 years later -- he joined the payload operations team at Marshall as a payload rack officer, or PRO, monitoring and configuring the resources for individual experiments from the ground.

"There is an Indonesian old saying, 'The mountain won't run away when you chase it,' which means, be patient in chasing your dream,” said Tanone. "My family thought I was throwing away a good career in computers and optics by chasing this dream. But how could I turn down the chance to be part of NASA history at the same facility Dr. von Braun helped create?"

In fact, the payload operations center where Tanone works is in a building used for Saturn V mission operations and later for space shuttle operations. Tanone achieved his dream and will end his career of supporting NASA when he retires at the end of March. Tanone and his co-workers can be proud that over 1,200 scientific results papers have been published on space station research and on supporting the completion of more than 400 experiments during astronaut Scott Kelly’s year in space on the space station. Discoveries cover a wide range of disciplines and include research that benefits both people on Earth and future explorers.

Space Station Live: Balancing a Year in Space

Video above: Flight controllers at the Payload Operations Integration Center at NASA’s Marshall Space Flight Center in Huntsville, Alabama, assisted astronaut Scott Kelly or his crewmates with more than 400 experiments conducted over the course of Kelly’s year in space on the International Space Station. Video Credit: NASA-TV.

For more information about the International Space Station (ISS), visit:

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

Related links:

Payload Operations Integration Center: http://www.nasa.gov/centers/marshall/earthorbit/ops.html

Commercial crew vehicles: http://www.nasa.gov/exploration/commercial/crew/index.html

Year in space: http://www.nasa.gov/content/one-year-crew

Images (mentioned), Video (mentioned), Text, Credits: NASA/Kristine Rainey.

Greetings, Orbiter.ch

SOFIA Observatory Indicates Star Eruptions Create and Scatter Elements with Earth-like Composition

NASA & DLR - SOFIA Telescope patch.

March 8, 2016

Observations made with NASA’s flying observatory, the Stratospheric Observatory for Infrared Astronomy (SOFIA) indicate that nova eruptions create elements that can form rocky planets, much like Earth.

Astronomers occasionally see a nova, which may appear as a “new” star that grows brighter and then fades away after a few weeks. In fact, “nova” (plural, novae) is the Latin word for “new.” We now know that novae are not actually new stars, but rather are associated with stellar old age: explosions occurring on the surfaces of burned-out stars. They are less violent and more common than the star-shattering explosions called supernovae that completely destroy an aging star.

Image above: An image from the Hubble Space Telescope showing debris expanding into space from a typical nova outburst that occurred decades before this picture. The featured research using SOFIA was focused on Nova Delphini 2013, which is too recent to allow a resolved picture of its debris cloud. Image Credits: NASA/ESA/STScI/AURA/NSF/Mike Shara, Bob Williams, David Zurek, Dina Prialnik.

Principal investigator Bob Gehrz of the University of Minnesota Twin Cities, and collaborators have been using SOFIA to study novae as part of an ongoing research program to understand the role these objects play in creating and injecting elements into the material between the stars called the interstellar medium.

Gerhz and his team found high levels of elements such as carbon, nitrogen, oxygen, neon, magnesium, aluminum and silicon in the Nova Delphini, which erupted in 2013 in the constellation Delphinum (the Dolphin). Some of these elements can be found in living things, whereas others are important constituents of rocky planets such as Earth.

There is evidence that when the universe began in the Big Bang, only trace amounts of elements other than hydrogen and helium were created. Atoms of heavier elements were made later by processes inside stars, or during star death throes such as nova and supernova explosions.

The observations of the Nova Delphini debris cloud indicate that novae in general may be a major source of medium-weight elements in the universe. Their paper was published in the Astrophysical Journal.

Image above: NASA’s Stratospheric Observatory for Infrared Astronomy 747SP taking off just before sunset from Air Force Plant 42 in Palmdale, California on Sept. 15, 2015. Image Credits: NASA Photo / Greg Perryman.

SOFIA’s Program Scientist Pam Marcum noted that “these spectra of Nova Delphinum could only be obtained by SOFIA, not by any observatory on the ground or currently in space, because of SOFIA’s unique access to the specific range of infrared wavelengths needed for these measurements.” She continued, “this research is part of the broad, ongoing effort by astronomers to understand the life cycles of stars, and how the formation of planets like Earth fit into those cycles.”

The observations for these findings were gathered with the FORCAST instrument on SOFIA, the Faint Object infraRed CAmera for the SOFIA Telescope, which can gather images and spectra of planets, stars, interstellar clouds and galaxies at mid-infrared wavelengths. SOFIA is a Boeing 747SP jetliner modified to carry a 100-inch diameter telescope. NASA’s Ames Research Center in Moffett Field, California manages the SOFIA program. The SOFIA Science Center is based at Ames and managed by NASA in cooperation with the Universities Space Research Association of Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is based at NASA's Armstrong Flight Research Center facility in Palmdale, California.

For more information about SOFIA mission, visit: http://www.nasa.gov/mission_pages/SOFIA/index.html

Related links:

Ames Research Center: https://www.nasa.gov/centers/ames/home/index.html

Armstrong Flight Research Center: https://www.nasa.gov/centers/armstrong/home/index.html

Images (mentioned), Text, Credits: NASA/SOFIA Science Center, NASA Ames Research Center/Dr. Dana Backman/Monroe Conner.

Greetings, Orbiter.ch

Sentinel-3A continues to impress

ESA - Sentinel 3 Mission logo.

8 March 2016

The three instruments on the Sentinel-3A satellite are now offering a tantalising glimpse of what’s in store for Europe’s Copernicus environmental monitoring effort. The latest images, which feature Europe and Antarctica, come from the sensor that records Earth’s radiant energy.

Launched just three weeks ago, Sentinel-3A carries a suite of cutting-edge instruments to provide systematic measurements of Earth’s oceans, land, ice and atmosphere.

Islands in red

This information will feed into numerous Copernicus services to monitor and manage our environment.

The satellite has already delivered impressive first images from its Ocean and Land Colour Instrument and its altimeter, and now the ‘radiometer’ has revealed its talents.

The Sea and Land Surface Temperature Radiometer measures the energy radiating from Earth’s surface in nine spectral bands, including visible and infrared.

In addition to providing the temperature of the land and sea surface, dedicated channels will search for fires. This will help to map carbon emissions from burnt biomass and to assess damage and estimate recovery of burned areas.

The first images come from the visible channels because the thermal-infrared channels have yet to be activated.

Ice cracked

One of the images features the Spanish Canary Islands, the Portuguese island of Madeira and the northwest coast of Africa. This false-colour image shows the vegetated islands in red, in contrast to Western Sahara, where there is little vegetation.

The snow-capped peak of Mount Teide on the island of Tenerife is also clearly visible in the image. Both the radiometer and the colour instrument will monitor plant health.

ESA’s Sentinel-3 project manager, Bruno Berruti, said, “It is very exciting to see all three instruments working well. Of course, it is still early days but we are looking to exploiting their full potential and use them together.

“For example, combining radiometer and colour data will help us to understand the state of the vegetation better.”

Another of the images from its visible channels shows a long crack running through the ice shelf to the east of the Antarctic Peninsula.

Europe viewed wide

The crack is about 2 km wide, but widens to 4 km or more in some places. There are also finer cracks and structures visible in the ice shelf.  Structure in the cloud, cloud shadows and details of the land emerging from the ice can also be seen.

An additional false-colour image, captured on 2 March, features a large part of Europe, demonstrating the instrument’s 1400 km-wide swath. It also shows vegetated areas in red as well as storm Jake over the UK.

EUMETSAT ocean remote sensing scientist, Anne O’Carroll, said, “These first images are very exciting and show the potential of this innovative instrument, which is the most advanced of its kind and eagerly awaited by the ocean science community.

Feeling the heat

“What’s new is that it records a double view of its path as it orbits Earth, which means that we get more accurate measurements of the temperature of the ocean surface. These measurements are crucial for operational weather and ocean forecasting, to follow climate cycles such as El Niño and to monitor changes in Earth’s climate.”

The thermal channels will be working in a few weeks but this latest Copernicus Sentinel has already impressed with its very first images, which will improve as operators spend the next five months fine-tuning and commissioning the satellite for operations.

Related articles:

Sentinel-3A rides the waves:
http://orbiterchspacenews.blogspot.ch/2016/03/sentinel-3a-rides-waves.html

First views of Earth from Sentinel-3A:
http://orbiterchspacenews.blogspot.ch/2016/03/first-views-of-earth-from-sentinel-3a.html

Related links:

Synthetic aperture radar mode: http://www.eetimes.com/document.asp?doc_id=1278931

Thales Alenia Space: http://www.thalesgroup.com/space/

International Ocean Colour Coordinating Group Meeting: http://www.ioccg.org/ioccg21.html

Copernicus: http://copernicus.eu/

EUMETSAT: http://www.eumetsat.int/website/home/index.html

Satellite Constellation: http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-3/Satellite_constellation

Images, Text, Credits: ESA/Copernicus data (2016)/ATG medialab.

Best regards, Orbiter.ch

Ahuna Mons on Ceres Seen From Low-Altitude Mapping Orbit

NASA - Dawn Mission patch.

March 7, 2016

The mysterious mountain Ahuna Mons is seen in this mosaic of images from NASA's Dawn spacecraft. Dawn took these images from its low-altitude mapping orbit, from an altitude of 240 miles (385 kilometers) in December 2015. The resolution of the component images is 120 feet (35 meters) per pixel.

On its steepest side, this mountain is about 3 miles (5 kilometers) high. Its average overall height is 2.5 miles (4 kilometers). These figures are slightly lower than what scientists estimated from Dawn's higher orbits because researchers now have a better sense of Ceres' topography.

The diameter of the mountain is about 12 miles (20 kilometers). Researchers are exploring the processes that could have led to this feature's formation.

Dawn's mission is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. For a complete list of acknowledgments, see http://dawn.jpl.nasa.gov/mission.

For more information about the Dawn mission, visit http://dawn.jpl.nasa.gov.

Image, Text, Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Tony Greicius.

Cheers, Orbiter.ch

The Saturnian Sisters

NASA - Cassini International logo.

March 7, 2016

Similar in many ways, Saturn's moons Tethys and Rhea (left and right, respectively) even share a discoverer: Giovanni Cassini, namesake of the NASA spacecraft that captured this view.

The moons are named for sisters -- two Titans of Greek mythology. Although somewhat different in size, Rhea (949 miles or 1,527 kilometers across) and Tethys (660 miles or 1,062 kilometers across) are medium-sized moons that are large enough to have pulled themselves into round shapes. They are both composed largely of ices and are generally thought to be geologically inactive today.

The view looks toward the anti-Saturn sides of Tethys and Rhea. North on both moons is up. The image was taken in visible red light with the Cassini spacecraft narrow-angle camera on Oct. 11, 2015.

The two moons appear close together here, but Tethys was about 220,000 miles (360,000 kilometers) farther away from Cassini when the image was captured -- nearly the distance from Earth to our moon. Thus, the view does not accurately reflect the bodies' relative sizes.

The image was obtained at a distance of approximately 708,000 miles (1.14 million kilometers) from Rhea. Image scale on Rhea is 4 miles (7 kilometers) per pixel. Tethys was 930,000 miles (1.5 million kilometers) away during this observation and has a pixel scale of 6 miles (9 kilometers) per pixel.

Cassini Spacecraft Animation

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Video, Text, Credits: NASA/ESA/JPL-Caltech/Space Science Institute/Tony Greicius.

Greetings, Orbiter.ch