A team of astronomers have identified the first direct evidence that groups of stars can tear apart their planet-forming disc, leaving it warped and with tilted rings. This new research suggests exotic planets, not unlike Tatooine in Star Wars, may form in inclined rings in bent discs around multiple stars. The results were made possible thanks to observations with the European Southern Observatory’s Very Large Telescope (ESO’s VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA).
Our Solar System is remarkably flat, with the planets all orbiting in the same plane. But this is not always the case, especially for planet-forming discs around multiple stars, like the object of the new study: GW Orionis. This system, located just over 1300 light-years away in the constellation of Orion, has three stars and a deformed, broken-apart disc surrounding them.
“Our images reveal an extreme case where the disc is not flat at all, but is warped and has a misaligned ring that has broken away from the disc,”
says Stefan Kraus, a professor of astrophysics at the University of Exeter in the UK who led the research published today in the journal Science. The misaligned ring is located in the inner part of the disc, close to the three stars.
The new research also reveals that this inner ring contains 30 Earth-masses of dust, which could be enough to form planets.
“Any planets formed within the misaligned ring will orbit the star on highly oblique orbits and we predict that many planets on oblique, wide-separation orbits will be discovered in future planet imaging campaigns, for instance with the ELT,”
says team member Alexander Kreplin of the University of Exeter, referring to ESO’s Extremely Large Telescope, which is planned to start operating later this decade. Since more than half the stars in the sky are born with one or more companions, this raises an exciting prospect: there could be an unknown population of exoplanets that orbit their stars on very inclined and distant orbits.
“We found that the three stars do not orbit in the same plane, but their orbits are misaligned with respect to each other and with respect to the disc,”
says Alison Young of the Universities of Exeter and Leicester and a member of the team.
They also observed the system with the SPHERE instrument on ESO’s VLT and with ALMA, in which ESO is a partner, and were able to image the inner ring and confirm its misalignment. ESO’s SPHERE also allowed them to see, for the first time, the shadow that this ring casts on the rest of the disc. This helped them figure out the 3D shape of the ring and the overall disc.
The international team, which includes researchers from the UK, Belgium, Chile, France and the US, then combined their exhaustive observations with computer simulations to understand what had happened to the system. For the first time, they were able to clearly link the observed misalignments to the theoretical “disc-tearing effect”, which suggests that the conflicting gravitational pull of stars in different planes can warp and break their discs.
Their simulations showed that the misalignment in the orbits of the three stars could cause the disc around them to break into distinct rings, which is exactly what they see in their observations. The observed shape of the inner ring also matches predictions from numerical simulations on how the disc would tear.
Interestingly, another team who studied the same system using ALMA believe another ingredient is needed to understand the system.
“We think that the presence of a planet between these rings is needed to explain why the disc tore apart,”
says Jiaqing Bi of the University of Victoria in Canada who led a study of GW Orionis published in The Astrophysical Journal Letters in May this year. His team identified three dust rings in the ALMA observations, with the outermost ring being the largest ever observed in planet-forming discs.
Future observations with ESO’s ELT and other telescopes may help astronomers fully unravel the nature of GW Orionis and reveal young planets forming around its three stars.
The European Southern Observatory’s Very Large Telescope (ESO’s VLT) has taken the first ever image of a young, Sun-like star accompanied by two giant exoplanets. Images of systems with multiple exoplanets are extremely rare, and — until now — astronomers had never directly observed more than one planet orbiting a star similar to the Sun. The observations can help astronomers understand how planets formed and evolved around our own Sun.
Just a few weeks ago, ESO revealed a planetary system being born in a new, stunning VLT image. Now, the same telescope, using the same instrument, has taken the first direct image of a planetary system around a star like our Sun, located about 300 light-years away and known as TYC 8998-760-1.
“This discovery is a snapshot of an environment that is very similar to our Solar System, but at a much earlier stage of its evolution,”
says Alexander Bohn, a PhD student at Leiden University in the Netherlands, who led the new research published today in The Astrophysical Journal Letters.
“Even though astronomers have indirectly detected thousands of planets in our galaxy, only a tiny fraction of these exoplanets have been directly imaged,” says co-author Matthew Kenworthy, Associate Professor at Leiden University, adding that “direct observations are important in the search for environments that can support life.”
The direct imaging of two or more exoplanets around the same star is even more rare; only two such systems have been directly observed so far, both around stars markedly different from our Sun. The new ESO’s VLT image is the first direct image of more than one exoplanet around a Sun-like star. ESO’s VLT was also the first telescope to directly image an exoplanet, back in 2004, when it captured a speck of light around a brown dwarf, a type of ‘failed’ star.
“Our team has now been able to take the first image of two gas giant companions that are orbiting a young, solar analogue,”
says Maddalena Reggiani, a postdoctoral researcher from KU Leuven, Belgium, who also participated in the study. The two planets can be seen in the new image as two bright points of light distant from their parent star, which is located in the upper left of the frame (click on the image to view the full frame). By taking different images at different times, the team were able to distinguish these planets from the background stars.
The two gas giants orbit their host star at distances of 160 and about 320 times the Earth-Sun distance. This places these planets much further away from their star than Jupiter or Saturn, also two gas giants, are from the Sun; they lie at only 5 and 10 times the Earth-Sun distance, respectively. The team also found the two exoplanets are much heavier than the ones in our Solar System, the inner planet having 14 times Jupiter’s mass and the outer one six times.
Bohn’s team imaged this system during their search for young, giant planets around stars like our Sun but far younger. The star TYC 8998-760-1 is just 17 million years old and located in the Southern constellation of Musca (The Fly). Bohn describes it as a “very young version of our own Sun.”
These images were possible thanks to the high performance of the SPHERE instrument on ESO’s VLT in the Chilean Atacama desert. SPHERE blocks the bright light from the star using a device called coronagraph, allowing the much fainter planets to be seen. While older planets, such as those in our Solar System, are too cool to be found with this technique, young planets are hotter, and so glow brighter in infrared light. By taking several images over the past year, as well as using older data going back to 2017, the research team have confirmed that the two planets are part of the star’s system.
Further observations of this system, including with the future ESO Extremely Large Telescope (ELT), will enable astronomers to test whether these planets formed at their current location distant from the star or migrated from elsewhere. ESO’s ELT will also help probe the interaction between two young planets in the same system. Bohn concludes:
“The possibility that future instruments, such as those available on the ELT, will be able to detect even lower-mass planets around this star marks an important milestone in understanding multi-planet systems, with potential implications for the history of our own Solar System.”
Xplore Inc., a commercial space exploration company providing Space as a Service™ today announced they and their teammates won a NASA Innovative Advanced Concepts (NIAC) Phase III award for a two-year, $2M NASA grant to further mature the Solar Gravity Lens Focus (SGLF) architecture to image planets in orbit around distant stars starting with a Technology Demonstration Mission (TDM). Dr. Slava G. Turyshev, a NIAC Fellow and Senior Research Scientist at NASA’s Jet Propulsion Laboratory (JPL) is the Principal Investigator leading the SGLF mission which includes Xplore, JPL and The Aerospace Corporation. The SGLF mission study is only the third Phase III award granted in the NIAC program ever.
Reaching the focus region where the Sun’s gravity acts like a magnifying lens to the background sky is an immense technological challenge. This region, the SGLF, is over 500 times the distance between Earth and the Sun (547 AU). One Astonomical Unit (AU) is the distance from Earth to the Sun, about 93 million miles (149.5 million km). Even by using our fastest deep space probe, Voyager 1, moving at 11 miles/s (17 km/s) it will take over 150 years to reach just the edge of the SGLF region.
During the previous two NIAC phases nearly every credible propulsion technology was assessed to not only accurately navigate across this vast distance, but also to communicate and operate once at the SGLF — all within a goal of 25 years from launch. To reach the SGLF on a timescale of 25 years requires a propulsion system capable of accelerating a spacecraft to a speed seven times faster than Voyager 1 (> 20 AU/yr or 100 km/s). The resulting propulsion technology was found to meet both the high speed requirement and the proposed architecture of sending many vehicles to the SGLF. This propulsion does not exploit chemical or nuclear reactions, but simply harnesses sunlight reflecting from a solar sail.
As a key enabler for the SGLF mission, Xplore will design the spacecraft for the SGLF’s Technology Demonstration Mission (TDM). The TDM vehicle as pictured is an advanced solar sail design based upon L’Garde’s SunVane concept. The SunVane concept addresses the control, packaging and scalability challenges of traditional large planar solar sails by breaking up the required overall sail area into smaller rotatable vanes distributed across a lightweight truss. Xplore will transition this concept to a prototype design as a first step toward demonstrating the key technologies necessary to achieve the SGLF mission. The goal for the Xplore TDM vehicle using current technologies is to reach speeds in excess of two to three times that of Voyager 1 (5-8 AU/year). At these unprecedented speeds it would allow the TDM vehicle to reach Jupiter in less than a year and Saturn in two years.
Xplore Founder Lisa Rich said,
“Xplore is laying the groundwork to revolutionize the transit speed to destinations in our solar system, and beyond. Once Xplore completes the design, build and first flight of the TDM vehicle, the company would accelerate these missions — perhaps sending one per year, to rapidly advance solar system exploration while providing fast reaction options for flybys of newly-discovered interstellar objects like Oumuamua and high energy intercepts for planetary defense.”
The TDM will enable rapid transit to dramatically transform and ease the exploration of the outer solar system and Kuiper belt objects. At 5-8 AU per year, the TDM vehicle’s extraordinary speed will allow it to reach Voyager in 20 years. To put these distances into perspective, New Horizons launched in 2006 and thirteen years later performed the first flyby of Ultima Thule, a distant Kuiper Belt object that lies 1 billion miles (1.6 billion km) beyond Pluto.
Alan Stern, planetary scientist, Associate Vice President of the Southwest Research Institute and the Principal Investigator on New Horizons mission to Pluto said,
“This is an incredible mission with incredible technology. I am incredibly excited to see it selected for study by NIAC. SGLF offers to revolutionize both exoplanet science and propulsion technology if implemented.”
The design of the TDM spacecraft is led by Xplore Founder and Chief Technology Officer, Dr. Darren Garber, who helped develop L’Garde’s SunVane concept and provided operational support to LightSail. Dr. Garber will coordinate with JPL and Aerospace team members to ensure that the TDM vehicle’s design and future flight will represent the next step toward traversing 500 AU in 25 years or less.
Dr. Louis D. Friedman, Xplore Advisor and Co-Founder of The Planetary Society, worked on numerous flagship missions including Mariner, Voyager, Magellan and the Mars Program. A well-known champion of the Halley’s Comet Rendezvous-Solar Sail project back in the 70s with Dr. Carl Sagan, Dr. Friedman said,
“I’m proud that Xplore, led by our colleague Dr. Slava Turyshev, will advance the vision for space exploration Carl Sagan and I put in motion many years ago. The ability to harness the power of the Sun to rapidly transit to distant corners of our universe is a groundbreaking effort that will impact the science community for generations.”
Xplore’s team is comprised entirely of experienced U.S. space professionals who have supported all aspects of the design, development and operations of advanced technology missions for commercial, civil and national security space customers.
For the TDM, Dr. Garber and Xplore’s advanced engineering team will leverage key components, software and system engineering processes employed for its Xcraft™, a high-performance, ESPA-class, multi-mission spacecraft uniquely designed for missions in the inner solar system with a planned lunar radar mapping mission in early 2022. Their expertise will further define the SGLF Phase III study mission and architecture analysis such as using clusters of follow-on TDM vehicles to collectively mitigate risk and lower total system cost. Multiple mass-produced TDM spacecraft offer resiliency and scalability for a future decades-long mission, and the concept could allow other partners to contribute their own set of clustered spacecraft to cooperatively operate during the journey to the solar gravitational lens region in deep space.
“Designing the fastest object ever made in the history of humanity is a challenge worthy of the legacy of Carl Sagan, and we look forward to advancing solar sail technologies with our Advisor, Dr. Lou Friedman. SGLF aligns with Xplore’s long-term vision for frequent, low-cost commercial missions to deep space. The ability to rapidly travel anywhere in the solar system expands our human footprint and will open up new avenues for scientific exploration.”
About Xplore Inc.: Xplore is a Seattle-based company offering Space as a Service™. Xplore provides hosted payloads, communication relay services and exclusive datasets to its customers via the Xcraft™, the company’s multi-mission spacecraft. Xplore’s mission is to expand robotic exploration via commercial missions at and beyond Earth, to the Moon, Mars, Venus, Lagrange points and near-Earth asteroids for national space agencies, national security agencies, sovereign space agencies and universities.
A sampling of recent articles, videos, and images from space-related science news items (find previous roundups here):
** What Does a Black Hole Look Like: How We Got Our First Picture – Dr. Eliot Quataert of the University of California, Berkeley gave this recent Silicon Valley Astronomy Lecture:
Black holes are one of the most remarkable predictions of Einstein’s theory of gravity: so much material is compressed into such a small volume that nothing, not even light, can escape. In Spring 2019, the world-wide Event Horizon Telescope released the first real picture of gas around a massive black hole and the “shadow” it makes as the gas swirls into the black hole. Dr. Quataert describes how these pioneering observations were made and what they have taught us about black
NASA’s Kepler spacecraft was designed to find exoplanets by looking for stars that dim as a planet crosses the star’s face. Fortuitously, the same design makes it ideal for spotting other astronomical transients – objects that brighten or dim over time. A new search of Kepler archival data has uncovered an unusual super-outburst from a previously unknown dwarf nova. The system brightened by a factor of 1,600 over less than a day before slowly fading away.
The star system in question consists of a white dwarf star with a brown dwarf companion about one-tenth as massive as the white dwarf. A white dwarf is the leftover core of an aging Sun-like star and contains about a Sun’s worth of material in a globe the size of Earth. A brown dwarf is an object with a mass between 10 and 80 Jupiters that is too small to undergo nuclear fusion.
The brown dwarf circles the white dwarf star every 83 minutes at a distance of only 250,000 miles (400,000 km) – about the distance from Earth to the Moon. They are so close that the white dwarf’s strong gravity strips material from the brown dwarf, sucking its essence away like a vampire. The stripped material forms a disk as it spirals toward the white dwarf (known as an accretion disk).
It was sheer chance that Kepler was looking in the right direction when this system underwent a super-outburst, brightening by more than 1,000 times. In fact, Kepler was the only instrument that could have witnessed it, since the system was too close to the Sun from Earth’s point of view at the time. Kepler’s rapid cadence of observations, taking data every 30 minutes, was crucial for catching every detail of the outburst.
The event remained hidden in Kepler’s archive until identified by a team led by Ryan Ridden-Harper of the Space Telescope Science Institute (STScI), Baltimore, Maryland, and the Australian National University, Canberra, Australia. “In a sense, we discovered this system accidentally. We weren’t specifically looking for a super-outburst. We were looking for any sort of transient,” said Ridden-Harper.
Kepler captured the entire event, observing a slow rise in brightness followed by a rapid intensification. While the sudden brightening is predicted by theories, the cause of the slow start remains a mystery. Standard theories of accretion disk physics don’t predict this phenomenon, which has subsequently been observed in two other dwarf nova super-outbursts.
NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star’s habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. Scientists confirmed the find, called TOI 700 d, using NASA’s Spitzer Space Telescope and have modeled the planet’s potential environments to help inform future observations.
“TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars,” said Paul Hertz, astrophysics division director at NASA Headquarters in Washington. “Planets around nearby stars are easiest to follow-up with larger telescopes in space and on Earth. Discovering TOI 700 d is a key science finding for TESS. Confirming the planet’s size and habitable zone status with Spitzer is another win for Spitzer as it approaches the end of science operations this January.”
In 2019, when Wolf Cukier finished his junior year at Scarsdale High School in New York, he joined NASA’s Goddard Space Flight Center in Greenbelt, Maryland, as a summer intern. His job was to examine variations in star brightness captured by NASA’s Transiting Exoplanet Survey Satellite (TESS) and uploaded to the Planet Hunters TESS citizen science project.
“I was looking through the data for everything the volunteers had flagged as an eclipsing binary, a system where two stars circle around each other and from our view eclipse each other every orbit,” Cukier said. “About three days into my internship, I saw a signal from a system called TOI 1338. At first I thought it was a stellar eclipse, but the timing was wrong. It turned out to be a planet.”
Engineers for NASA’s Voyager 2 spacecraft are working to return the mission to normal operating conditions after one of the spacecraft’s autonomous fault protection routines was triggered. Multiple fault protection routines were programmed into both Voyager 1 and Voyager 2 in order to allow the spacecraft to automatically take actions to protect themselves if potentially harmful circumstances arise. At NASA’s Jet Propulsion Laboratory in Pasadena, California, engineers are still communicating with the spacecraft and receiving telemetry.
Launched in 1977, Voyager 1 and Voyager 2 are both in interstellar space, making them the most distant human-made objects in the solar system. On Saturday, Jan. 25, Voyager 2 didn’t execute a scheduled maneuver in which the spacecraft rotates 360 degrees in order to calibrate its onboard magnetic field instrument. Analysis of the telemetry from the spacecraft indicated that an unexplained delay in the onboard execution of the maneuver commands inadvertently left two systems that consume relatively high levels of power operating at the same time. This caused the spacecraft to overdraw its available power supply.
It’s a long way to make a service call:
It has taken the team several days to assess the current situation primarily because of Voyager 2’s distance from Earth – about 11.5 billion miles (18.5 billion kilometers). Communications traveling at the speed of light take about 17 hours to reach the spacecraft, and it takes another 17 hours for a response from the spacecraft to return to Earth. As a result, mission engineers have to wait about 34 hours to find out if their commands have had the desired effect on the spacecraft.
In the month of December 2019 the Sun continued its longest stretch of overall sunspot inactivity ever recorded, reaching seven months in length. At no point since the last grand minimum in the 1600s have scientists ever seen so few sunspots over so long a time period.
December saw only two sunspots, both becoming active on the same day, December 24. Both also had a polarity belonging to the next solar cycle, providing evidence that we will have another sunspot maximum sometime in the next five years, and that we are not heading to another grand minimum where there are no sunspots for decades.
At 4:37 a.m. EST on Jan. 29, 2020, NASA’s Parker Solar Probe broke speed and distance records as it completed its fourth close approach of the Sun. The spacecraft traveled 11.6 million miles from the Sun’s surface at perihelion, reaching a speed of 244,225 miles per hour. These achievements topple Parker Solar Probe’s own previous records for closest spacecraft to the Sun — previously about 15 million miles from the Sun’s surface — and fastest human-made object, before roughly 213,200 miles per hour.
Parker Solar Probe will continue to fly ever closer to the Sun on its seven-year journey, exploring regions of space never visited before and providing scientists with key measurements to help unveil the mysteries of the solar corona and wind.
As with most of Parker Solar Probe’s close approaches, the spacecraft is out of contact with Earth for several days around perihelion.
There’s a wind that emanates from the Sun. It blows not like a soft whistle but like a hurricane’s scream. Made of electrons, protons and heavier ions, the solar wind courses through the solar system at roughly 1 million mph (1.6 million kph), barreling over everything in its path. Yet through the wind’s roar, NASA’s Parker Solar Probe hears the small chirps, squeaks and rustles that hint at the origin of this mysterious and ever-present wind. The spacecraft’s FIELDS instrument can eavesdrop on the electric and magnetic fluctuations caused by plasma waves. The Parker Solar Probe it can “hear” when the waves and particles interact with one another, recording frequency and amplitude information about these plasma waves that scientists could then play as sound waves. And it results in some striking sounds. Solar wind sounds playlist: https://soundcloud.com/jhu-apl/sets/s…
It’s more massive than all the other planets combined. In nearly four years at Jupiter the Juno spacecraft has returned science that is revolutionizing our understanding of this gigantic world. Principal investigator Scott Bolton shows us the mysterious cyclones at its poles and that famously persistent red spot. Casey Dreier says the United States House of Representatives has proposed legislation that is at odds with NASA’s current Moon and Mars plans. John Flamsteed almost discovered Uranus! Bruce Betts will tell us where he went wrong in this week’s What’s Up space trivia contest.
Chinese officials marked the one-year anniversary of the Chang’e 4 mission’s historic first soft landing on the far side of the moon [January 3rd] with the public release of data collected by scientific instruments and cameras on the lunar lander and rover.
The Chang’e 4 lander and Yutu 2 rover landed together on the lunar surface Jan. 3, 2019, marking the first time a spacecraft has ever safely touched down on the far side of the moon.
Around 12 hours after touchdown, the Yutu 2 rover drove down a ramp to disembark from the Chang’e 4 mission’s stationary landing platform to begin exploring the barren lunar landscape.
Scientific instruments and cameras aboard the Chang’e 4 lander and Yutu 2 rover have downlinked measurements and numerous images in the past year. The Chang’e 4 mission relays data through a dedicated Chinese communications satellite positioned beyond the far side of the moon, with a line of sight to both Chang’e 4 and Earth-based receiving stations.
On Friday, the one-year anniversary of the mission’s successful landing, China National Space Administration and the Chinese Academy of Sciences published scientific data collected by five instruments on the Chang’e 4 lander and Yutu 2 rover.
After a year scoping out asteroid Bennu’s boulder-scattered surface, the team leading NASA’s first asteroid sample return mission has officially selected a sample collection site.
The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-Rex) mission team concluded a site designated “Nightingale” – located in a crater high in Bennu’s northern hemisphere – is the best spot for the OSIRIS-REx spacecraft to snag its sample.
The OSIRIS-REx team spent the past several months evaluating close-range data from four candidate sites in order to identify the best option for the sample collection. The candidate sites – dubbed Sandpiper, Osprey, Kingfisher, and Nightingale – were chosen for investigation because, of all the potential sampling regions on Bennu, these areas pose the fewest hazards to the spacecraft’s safety while still providing the opportunity for great samples to be gathered.
Preliminary results indicate that NASA’s OSIRIS-REx spacecraft successfully executed a 0.4-mile (620-m) flyover of site Nightingale yesterday as part of the mission’s Reconnaissance B phase activities. Nightingale, OSIRIS-REx’s primary sample collection site, is located within a crater high in asteroid Bennu’s northern hemisphere.
To perform the pass, the spacecraft left its 0.75-mile (1.2-km) safe home orbit and flew an almost 11-hour transit over the asteroid, aiming its science instruments toward the 52-ft (16-m) wide sample site before returning to orbit. Science observations from this flyover are the closest taken of a sample site to date.
The primary goal of the Nightingale flyover was to collect the high-resolution imagery required to complete the spacecraft’s Natural Feature Tracking image catalog, which will document the sample collection site’s surface features – such as boulders and craters. During the sampling event, which is scheduled for late August, the spacecraft will use this catalog to navigate with respect to Bennu’s surface features, allowing it to autonomously predict where on the sample site it will make contact . Several of the spacecraft’s other instruments also took observations of the Nightingale site during the flyover event, including the OSIRIS-REx Thermal Emissions Spectrometer (OTES), the OSIRIS-REx Visual and InfraRed Spectrometer (OVIRS), the OSIRIS-REx Laser Altimeter (OLA), and the MapCam color imager.
After making good progress in recent weeks, another day of digging on #Mars leads to the mole backing out by a couple of centimeters. My team keeps pushing forward and is exploring several options. pic.twitter.com/pe2eopDANi
The joint European/Russian ExoMars 2020 mission aims to launch on a Russian Proton rocket this summer and land on Mars on March 19, 2021. Problems with the parachutes need to be resolved else the mission will have to wait another two years for the next launch window: Promising progress for ExoMars parachutes – ESA
Dr. Courtney Dressing of the University of California at Berkeley gives a public lecture on exoplanets:
The NASA Kepler mission revealed that our Galaxy is teeming with planetary systems and that Earth-sized planets are common. However, most of the planets detected by Kepler orbit stars too faint to permit detailed study. The NASA Transiting Exoplanet Survey Satellite (TESS,) launched in 2018, is now finding hundreds of small planets orbiting stars that are much closer and brighter. Dr. Dressing discusses how we find exoplanets, describes the TESS mission, and explains how it (and future projects) will help our understanding of what planets are out there and how they form.
The lecture is one in the Silicon Valley Astronomy Lectures series organized and moderated by Foothill’s astronomy instructor Andrew Fraknoi and jointly sponsored by the Foothill College Astronomy Department, NASA’s Ames Research Center, the SETI Institute, and the Astronomical Society of the Pacific.