LHCb finds new hints of possible Standard Model deviations

CERN - European Organization for Nuclear Research logo.

April 20, 2017

The LHCb experiment finds intriguing anomalies in the way some particles decay. If confirmed, these would be a sign of new physics phenomena not predicted by the Standard Model of particle physics. The observed signal is still of limited statistical significance, but strengthens similar indications from earlier studies. Forthcoming data and follow-up analyses will establish whether these hints are indeed cracks in the Standard Model or a statistical fluctuation.

On April 18, in a seminar at CERN, the LHCb collaboration presented new long-awaited results on a particular decay of B⁰ mesons produced in collisions at the Large Hadron Collider. The Standard Model of particle physics predicts the probability of the many possible decay modes of B⁰ mesons, and possible discrepancies with the data would signal new physics.

The LHCb cavern (Image: Maximilien Brice/CERN)

In this study, the LHCb collaboration looked at the decays of B⁰ mesons to an excited kaon and a pair of electrons or muons. The muon is 200 times heavier than the electron, but in the Standard Model its interactions are otherwise identical to those of the electron, a property known as lepton universality. Lepton universality predicts that, up to a small and calculable effect due to the mass difference, electron and muons should be produced with the same probability in this specific B⁰ decay. LHCb finds instead that the decays involving muons occur less often.

While potentially exciting, the discrepancy with the Standard Model occurs at the level of 2.2 to 2.5 sigma, which is not yet sufficient to draw a firm conclusion. However, the result is intriguing because a recent measurement by LHCb involving a related decay exhibited similar behaviour. 

While of great interest, these hints are not enough to come to a conclusive statement. Although of a different nature, there have been many previous measurements supporting the symmetry between electrons and muons. More data and more observations of similar decays are needed in order to clarify whether these hints are just a statistical fluctuation or the first signs for new particles that would extend and complete the Standard Model of particles physics. The measurements discussed were obtained using the entire data sample of the first period of exploitation of the Large Hadron Collider (Run 1). If the new measurements indeed point to physics beyond the Standard Model, the larger data sample collected in Run 2 will be sufficient to confirm these effects.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related link:

LHCb website: http://lhcb-public.web.cern.ch/lhcb-public/Welcome.html#RKstar

For more information about European Organization for Nuclear Research (CERN), Visit: http://home.cern/

Image (mentioned), Text, Credits: CERN/Harriet Kim Jarlett.

Best regards, Orbiter.ch (CERN's neighbor)

Crystals Grown Aboard Space Station Provide Radiation Detecting Technology

ISS - International Space Station logo.

April 20, 2017

Research into crystal growth in microgravity was one of the earliest investigations conducted aboard the International Space Station and is continued to this day. The unique microgravity environment of space provides an ideal setting for producing crystals that are more perfect than their terrestrial-grown counterparts. The Crystal Growth of Cs2LiYCl6:Ce Scintillators in Microgravity (CLYC-Crystal Growth), a Center for the Advancement of Science in Space (CASIS)-sponsored investigation, will study the potential benefits of growing the CYLC crystal in microgravity.

The CLYC crystal is a special kind of multicomponent crystal system used to make scintillator radiation detectors, a device that is sensitive to both gamma rays and neutrons.

Image above: The Solidification Using a Baffle in Sealed Ampoules (SUBSA) hardware being installed by NASA astronaut Peggy Whitson during Expedition 5. The SUBSA Furnace and Inserts investigation includes modernized data acquisition, high definition video and communication interfaces. Image Credit: NASA.

“It’s a spectroscopic crystal, which means, using this crystal, we can detect the presence and intensity of radiation, as well as identify which isotopes emit radiation by measuring the energy,” said Dr. Alexei Churilov, primary investigator and senior scientist at Radiation Monitoring Devices Inc. (RMD).

The CLYC crystal is produced as a commercial product by RMD and is largely used to detect and differentiate both harmful and harmless levels of radiation. The crystal’s main application is homeland security as a method of detected smuggled nuclear materials, but may also be used for oil and gas exploration, medical imaging, particle and space physics and scientific instruments.

However, the Earth-grown crystals have shown defects such as cracks, grain boundaries and inclusions, incidents which scientists like Churilov hope to eliminate by using the space station’s microgravity environment as a growth habitat.

Image above: Flight ampoules for CLYC Crystal Growth samples, to be transported to the International Space Station. Resulting crystals will be compared against on-ground samples to develop on-Earth techniques for crystal growth. Image Credit: Alexei Churilov.

Research has shown that many, though not all, crystals benefit from growth in microgravity. Although the reasoning behind this phenomena is still being investigated, research points to the lack of buoyancy-induced convection, which affects transport of molecules in the crystal.

“Our ultimate goal is to study the growth of CLYC in microgravity without the interference of convection and to improve the production of the crystal on Earth,” said Churilov.

The research for the CLYC Crystal Growth investigation will be conducted within the Solidification Using a Baffle in Sealed Ampoules Furnaces and Inserts (SUBSA Furnaces and Inserts). SUBSA helps researchers advance the understanding of processes involved in semiconductor crystal growth. It offers a gradient freeze furnace for materials science investigations. SUBSA was originally operated aboard the space station in 2002, the SUBSA hardware has been modernized and updated with data acquisition, high resolution video and communication interfaces.

Image above: CLYC crystals grown in on Earth often contain imperfections such as inclusions (left), cracks (middle) and grain boundaries (right). The goal is to understand their formation without the interference of convection to improve crystal growth on Earth. Image Credit: Alexei Churilov.

During the investigation, four crystal growth runs will be conducted aboard the space station and then in the ground-based SUBSA furnaces, giving researchers a view into the gravitational effect on their growth. Once the investigation is complete, the space-grown crystals will be compared against their counterparts on Earth and tested for imperfections and effectiveness as radiation detectors.

Although microgravity can’t be mimicked or reproduced on the ground, results from the investigation will provide information about which crystal methods to use on Earth, how to improve ampoule and furnace design and which crystal growth parameters to change in pursuit of a more perfect crystallization process.

CASIS Orbital ATK CRS-7 Payload Overview

Though the total weight of the CLYC Crystal Growth investigation is small, only a few kilograms together with packaging, the benefits can be immense as the data gathered during the investigation will be put to immediate use in the production of CLYC crystals.

Follow https://twitter.com/ISS_Research for more information about the science happening on the space station.

Related links:

Crystal Growth of Cs2LiYCl6:Ce Scintillators in Microgravity (CLYC-Crystal Growth): https://www.nasa.gov/mission_pages/station/research/experiments/2353.html

Center for the Advancement of Science in Space (CASIS): http://www.iss-casis.org/

Solidification Using a Baffle in Sealed Ampoules Furnaces and Inserts (SUBSA Furnaces and Inserts): https://www.nasa.gov/mission_pages/station/research/experiments/316.html

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

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

Images (mentioned), Video, Text, Credits: NASA/Kristine Rainey/JSC/Jenny Howard/CASIS.

Greetings, Orbiter.ch

Landslides on Ceres Reflect Ice Content

NASA - Dawn Mission patch.

April 20, 2017

Images above: NASA's Dawn spacecraft has revealed many landslides on Ceres, which researchers interpret to have been shaped by a significant amount of water ice. Shown are examples of Type I (left), Type II (middle) and Type III (right). Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

As NASA's Dawn spacecraft continues exploring Ceres, evidence mounts that the enigmatic dwarf planet retains a significant amount of water ice. A new study in the journal Nature Geoscience adds to this picture, showing how ice may have shaped the variety of landslides seen on Ceres today.

"Images from Dawn show that landslides, many of which are similar to those seen on Earth, are very common on Ceres, and further the case that Ceres has a lot of water ice involved in its structure," said Britney Schmidt, who led the study. She is an associate of the Dawn science team and assistant professor at Georgia Institute of Technology in Atlanta. 

Types of Landslides

Schmidt and colleagues identified three types of landslides. Type I, which are relatively round and large, have thick "toes" at their ends. They look similar to rock glaciers and icy landslides on Earth. Type I landslides are mostly found at high latitudes on Ceres, which is also where the most ice is thought to reside just beneath the surface, suggesting they involve the most ice of any of the flow features. Three small Type 1 flows are found in Oxo Crater, a tiny bright crater in the northern hemisphere that hosts an ice deposit at the surface. 

Type II features are often thinner and longer than Type I, and are the most common type of landslide on Ceres. The landslide deposits appear similar to those left behind by avalanches seen on Earth.

Ceres' Type III features may involve a brief melting of some of the ice within the soil-like regolith, causing the material to flow like mud before refreezing. These landslides are always associated with large impact craters, and may have formed when an impact event melts subsurface ice on Ceres. These features have similar appearances to ejected material from craters in the icy regions of Mars and on Jupiter's moon Ganymede.

"The locations of these different types of features reinforces the idea that the shallow subsurface of Ceres is a mixture of ice and rock, and that ice is most plentiful near the surface at the poles," Schmidt said.

Scientists were also surprised at just how many landslides have occurred on Ceres in general. About 20 to 30 percent of craters greater than 6 miles (10 kilometers) wide have some type of landslide associated with them. Such widespread "ground ice" features, which formed from of a mixture of rock and ice, had only been observed before on Earth and Mars.

Implications and Future Observations

Based on the shape and distribution of landslides on Ceres, study authors estimate that the ice in the upper few tens of meters of Ceres may range from 10 percent to 50 percent by volume.

"These kinds of flows are not seen on bodies such as Vesta, which Dawn studied from 2011 to 2012, because the regolith is devoid of water," said Carol Raymond, deputy principal investigator for the Dawn mission, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

Now in its extended mission phase, Dawn is using its ion engine to swivel the plane of its orbit around Ceres to prepare for observations from a new orbit and orientation. At the end of April, the spacecraft will be directly between the sun and the mysterious Occator Crater. In this geometry, Dawn may deliver new insights about the reflective material of Ceres' most famous "bright spot," the highly reflective center of Occator that has been named Cerealia Facula.

Dawn spacecraft at Ceres. Image Credit: NASA

The Dawn mission is managed by JPL 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, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: https://dawn.jpl.nasa.gov/mission

More information about Dawn is available at the following sites:

https://www.nasa.gov/dawn

https://dawn.jpl.nasa.gov

Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Elizabeth Landau.

Greetings, Orbiter.ch

Planet Hunters Named in TIME’s Top 100 Most Influential People

NASA - Kepler Space Telescope patch.

April 20, 2017

Three extraordinary planet-hunters have been recognized by TIME Magazine as this year’s top 100 most influential people: Natalie Batalha from NASA’s Ames Research Center in California’s Silicon Valley; Michael Gillon from the University of Liège in Belgium; and Guillem Anglada-Escudé from the Queen Mary University in London.

“It is truly exciting to see these planet-hunters among the other movers and the shakers of the world,” said Paul Hertz, Astrophysics division director at Headquarters in Washington. “These scientists have transformed the world’s understanding of our place in the universe, and NASA congratulates them for their well-deserved recognition.”

Natalie Batalha is the project scientist for NASA’s Kepler mission, the agency’s first dedicated planet-seeking mission tasked to determine whether worlds around other stars are common by looking for telltale dips in a star’s brightness caused by crossing, or transiting, planets. Thanks to Kepler, some scientists believe there is at least one world around every star in the sky. To date, Kepler has found more than 2500 planets, including a “bigger, older cousin” to Earth. In total, the Kepler spacecraft has found nearly 5100 possible planets. Batalha is the first woman at NASA to receive the Time 100 designation. Read more about Batalha’s accomplishments: https://www.nasa.gov/feature/ames/kepler/kepler-scientist-on-time-magazine-most-influential-list

Michael Gillon led the research that discovered seven Earth-size planets around TRAPPIST-1, a nearby ultra-cool dwarf star, approximately 40 light years away. He is the principal investigator of the TRAPPIST (“The Transiting Planets and Planetesimals Small Telescope”) project, a pair of telescopes in Chile and Morocco. In 2016, Gillon and colleagues announced three planets around TRAPPIST-1. Following up with NASA’s Spitzer Space Telescope and ground-based telescopes, Gillon and colleagues revealed in 2017 that there are actually seven planets around the star. Three of the seven worlds of TRAPPIST-1 are in the habitable zone, but any of them could have liquid water. The TRAPPIST-1 planets are some of the best targets for NASA’s upcoming James Webb Space Telescope to look for signs of habitability. Gillon is also the project leader and principal investigator of SPECULOOS, an upcoming ground-based telescope project for which TRAPPIST is the prototype. Read more about the TRAPPIST-1 discovery: Ultracool Dwarf and the Seven Planets http://orbiterchspacenews.blogspot.ch/2017/02/ultracool-dwarf-and-seven-planets.html

Guillem Anglada-Escudé led the research team who discovered Proxima b, a roughly Earth-sized exoplanet orbiting at a distance from its star that would allow temperatures mild enough for liquid water to pool on its surface. Proxima b orbits our nearest neighboring star Proxima Centauri just over four light-years from Earth. Proxima is the smallest member of a triple star system known as Alpha Centauri and is the closest star to Earth, besides our own sun. Read more about the European Southern Observatory-led Proxima b discovery.

Anglada-Escude’s research spans the realm of astrobiology, the study of the origin, evolution, distribution, and future of life in the universe. From 2009 to 2013, Anglada-Escude participated in a research study to learn more about life's chemical and physical evolution, from the interstellar medium, through planetary systems, to the emergence and detection of life. Learn more about the five-year research study supported by the NASA Astrobiology Institute: https://nai.nasa.gov/teams/can-5/ciw

NASA’s search for distant worlds continues with the Transiting Exoplanet Survey Satellite (TESS) launching in 2018, which will find new planets the same way Kepler does, but right in the stellar backyard of our solar system, covering 400 times the sky area. Webb will also launch in 2018, and peer into possible atmospheres of distant worlds to look for chemical hints of life.

For more information, visit:

TIME Magazine year’s top 100 most influential people: http://time.com/collection/2017-time-100/4742707/natalie-batalha-guillem-anglada-escude-michael-gillon/

Exoplanets: https://www.nasa.gov/content/the-search-for-life

Kepler and K2: https://www.nasa.gov/mission_pages/kepler/main/index.html

James Webb Space Telescope (JWST): https://www.nasa.gov/mission_pages/webb/main/index.html

Illustration, Text, Credits: NASA/Sarah Loff.

Greetings, Orbiter.ch

Commercial Crew Spacecraft Will Offer a Quick Escape from Station

ISS - International Space Station patch.

April 20, 2017

New, American-made spacecraft flying to the International Space Station will play a big role in bringing resident crews back home to Earth, but their missions also include the ability to provide the orbiting laboratory with a temporary shelter in case of an emergency in space, or even a safe ride back to Earth with short notice.

The scenarios that would call for the spacecraft to operate as space-borne lifeboats have not occurred on the International Space Station before, but mission planners have long made sure they are prepared. An electrical issue or ammonia leak on the space station could call for astronauts to shelter inside a Commercial Crew Program spacecraft long enough to correct the problem.

A medical emergency requiring surgery on an astronaut would be a case demanding immediate evacuation from orbit to Earth, something the spacecraft supporting NASA missions would be equipped to handle. The Soyuz spacecraft handle the lifeboat capability needs for the station's current crews.

The need for a quick departure is more than a luxury for the space station. Every person on the orbiting complex has a specific emergency seat assigned throughout their mission that they have to get to if the need arises. Because there are limits to how many seats are available at a time, there also is a limit to how many residents can live and work there.

What does it mean for a spacecraft to be capable of serving as a lifeboat? As with all the needs for the new spacecraft, NASA outlined a list of requirements for designers to meet. For the most part, it means the spacecraft can be powered on quickly while docked to the station, even if it has been dormant for weeks or a couple of months. From air circulation fans to life support systems to thrusters, the spacecraft's systems will be designed to engage in minutes.

"Some systems will take longer to bring online, but the idea is to have spacecraft that astronauts can get into quickly for survival and then use to pull away from the station and come home if that is needed," said Kathy Lueders, manager of NASA's Commercial Crew Program. "Defining exactly what that means, and what the companies can do to make it real was the hard part. That's why we took a teamwork approach from the start and why we've treated this as a partnership."

Boeing and SpaceX, each working on their own crew-capable spacecraft — the CST-100 Starliner and Crew Dragon, respectively — are testing their systems thoroughly on Earth before they undergo evaluation in orbit without a crew aboard, and then on a short mission with astronauts. Their performances in space – without an actual emergency – are to be considered carefully before NASA certifies the companies to fly operational missions, which could see a spacecraft docked to the station for months at a time.

Related links:

Commercial Crew: https://www.nasa.gov/exploration/commercial/crew/index.html

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

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

Illustration (banner), Text, Credits: NASA's Kennedy Space Center, by Steven Siceloff.

Greetings, Orbiter.ch

Two New Crew Members Arrive at International Space Station

ROSCOSMOS - Soyuz MS-04 Mission patch.

April 20, 2017

Expedition 51-52 Crew Docks to the Space Station

After a six-hour flight, NASA astronaut Jack Fischer and cosmonaut Fyodor Yurchikhin of the Russian space agency Roscosmos arrived at the International Space Station at 9:18 a.m. EDT Thursday where they will continue important scientific research.

The two launched aboard a Soyuz MS-04 spacecraft from the Baikonur Cosmodrome in Kazakhstan at 3:13 a.m. (1:13 p.m. Baikonur time), orbited Earth four times, and docked at the space station.

Expedition 51-52 Crew Welcomed Aboard the Space Station

The arrival of Fischer and Yurchikhin increased the station's crew complement to five. The two join Expedition 51 Commander Peggy Whitson of NASA and Flight Engineers Oleg Novitskiy of Roscosmos and Thomas Pesquet of ESA (European Space Agency). The Expedition 51 crew members will spend more than four months conducting approximately 250 science investigations in fields such as biology, Earth science, human research, physical sciences and technology development.

Novitskiy and Pesquet will remain aboard the station until early June. Fischer and Yurchikhin are scheduled to remain aboard the station until September, along with Whitson, whose stay aboard the station was extended into Expedition 52 by an agreement recently signed between NASA and Roscosmos.

Images above: The Soyuz MS-04 rocket launches from the Baikonur Cosmodrome in Kazakhstan April 20, 2017, carrying Expedition 51 Soyuz Commander Fyodor Yurchikhin of Roscosmos and Flight Engineer Jack Fischer of NASA into orbit to begin their four and a half month mission on the International Space Station. Image Credits: NASA/Aubrey Gemignani.

The expanded Expedition 51 crew soon will conduct new science investigations arriving on Orbital ATK’s seventh NASA-contracted commercial resupply mission Saturday, April 22. Investigations arriving will include an antibody investigation that could increase the effectiveness of chemotherapy drugs for cancer treatment and an advanced plant habitat for studying plant physiology and growth of fresh food in space. Another new investigation bound for the U.S. National Laboratory will look at using magnetized cells and tools to make it easier to handle cells and cultures, and improve the reproducibility of experiments. Cygnus also is carrying 38 CubeSats, including many built by university students from around the world, as part of the QB50 program. The CubeSats are scheduled to deploy from either the spacecraft or space station in the coming months.

Fischer and Whitson are scheduled to take part in the fifth spacewalk of the year on May 12. The pair’s main task will be to replace an avionics box on the starboard truss called an ExPRESS Logistics Carrier, a storage platform. The box houses electrical, and command and data routing equipment for science experiments and replacement hardware stored outside the station. The new avionics box is arriving aboard Orbital ATK’s Cygnus cargo craft on Saturday, April 22.

Image above: Expedition 51 Soyuz Commander Fyodor Yurchikhin of Roscosmos and Flight Engineer Jack Fischer of NASA wave farewell prior to boarding the Soyuz MS-04 spacecraft for launch April 20, 2017, at the Baikonur Cosmodrome in Kazakhstan. Image Credits: NASA/Aubrey Gemignani.

The crew members also are scheduled to receive one Russian Progress resupply mission delivering several tons of food, fuel, supplies and research.

For more than 16 years, humans have lived and worked continuously aboard the International Space Station, advancing scientific knowledge and demonstrating new technologies, making research breakthroughs not possible on Earth that will enable long-duration human and robotic exploration into deep space. A global endeavor, more than 200 people from 18 countries have visited the unique microgravity laboratory that has hosted more than 1,900 research investigations from researchers in more than 95 countries.

Related links:

Expedition 51: https://www.nasa.gov/mission_pages/station/expeditions/expedition51/index.html

Antibody investigation: https://www.nasa.gov/mission_pages/station/research/experiments/2347.html

Advanced plant habitat: http://orbiterchspacenews.blogspot.ch/2017/03/new-plant-habitat-will-increase-harvest.html

Magnetized cells and tools: https://www.nasa.gov/mission_pages/station/research/experiments/1929.html

QB50 program: https://www.nasa.gov/mission_pages/station/research/experiments/2539.html

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

Images (mentioned), Videos (NASA TV), Text, Credits: NASA/Karen Northon/Kathryn Hambleton/JSC/Dan Huot.

Best regards, Orbiter.ch

Hubble observes first multiple images of explosive distance indicator

ESA - Hubble Space Telescope logo.

20 April 2017

Lensed supernova will give insight into the expansion of the Universe

Detailed look at a gravitationally lensed supernova

A Swedish-led team of astronomers used the NASA/ESA Hubble Space Telescope to analyse the multiple images of a gravitationally lensed type Ia supernova for the first time. The four images of the exploding star will be used to measure the expansion of the Universe. This can be done without any theoretical assumptions about the cosmological model, giving further clues about how fast the Universe is really expanding. The results are published in the journal Science.

Hubble’s view on lensing galaxy

An international team, led by astronomers from the Stockholm University, Sweden, has discovered a distant type Ia supernova, called iPTF16geu [1] — it took the light 4.3 billion years to travel to Earth [2]. The light from this particular supernova was bent and magnified by the effect of gravitational lensing so that it was split into four separate images on the sky [3]. The four images lie on a circle with a radius of only about 3000 light-years around the lensing foreground galaxy, making it one of the smallest extragalactic gravitational lenses discovered so far. Its appearance resembles the famous Refsdal supernova, which astronomers detected in 2015 (heic1525). Refsdal, however, was a core-collapse supernova.

Hubble’s view on lensed supernova

Type Ia supernovae always have the same intrinsic brightness, so by measuring how bright they appear astronomers can determine how far away they are. They are therefore known as standard candles. These supernovae have been used for decades to measure distances across the Universe, and were also used to discover its accelerated expansion and infer the existence of dark energy. Now the supernova iPTF16geu allows scientists to explore new territory, testing the theories of the warping of spacetime on smaller extragalactic scales than ever before.

Palomar’s view on iPTF16geu

“Resolving, for the first time, multiple images of a strongly lensed standard candle supernova is a major breakthrough. We can measure the light-focusing power of gravity more accurately than ever before, and probe physical scales that may have seemed out of reach until now,” says Ariel Goobar, Professor at the Oskar Klein Centre at Stockholm University and lead author of the study.

The SDSS view on iPTF16geu

The critical importance of the object meant that the team instigated follow-up observations of the supernova less than two months after its discovery. This involved some of the world’s leading telescopes in addition to Hubble: the Keck telescope on Mauna Kea, Hawaii, and ESO’s Very Large Telescope in Chile. Using the data gathered, the team calculated the magnification power of the lens to be a factor of 52. Because of the standard candle nature of iPTF16geu, this is the first time this measurement could be made without any prior assumptions about the form of the lens or cosmological parameters.

Keck’s view on lensed supernova

Currently the team is in the process of accurately measuring how long it took for the light to reach us from each of the four images of the supernova. The differences in the times of arrival can then be used to calculate the Hubble constant — the expansion rate of the Universe — with high precision [4]. This is particularly crucial in light of the recent discrepancy between the measurements of its value in the local and the early Universe (heic1702).

Schematic of strong gravitational lensing

As important as lensed supernovae are for cosmology, it is extremely difficult to find them. Not only does their discovery rely on a very particular and precise alignment of objects in the sky, but they are also only visible for a short time. “The discovery of iPTF16geu is truly like finding a somewhat weird needle in a haystack,” remarks Rahman Amanullah, co-author and research scientist at Stockholm University. “It reveals to us a bit more about the Universe, but mostly triggers a wealth of new scientific questions.”

 Hubble Space Telescope

Studying more similarly lensed supernovae will help shape our understanding of just how fast the Universe is expanding. The chances of finding such supernovae will improve with the installation of new survey telescopes in the near future.

Notes:

[1] iPTF16geu was initially observed by the iPTF (intermediate Palomar Transient Factory) collaboration with the Palomar Observatory. This is a fully automated, wide-field survey delivering a systematic exploration of the optical transient sky.

[2] This corresponds to a redshift of 0.4. The lensing galaxy has a redshift of 0.2.

[3] Gravitational lensing is a phenomenon that was first predicted by Albert Einstein in 1912. It occurs when a massive object lying between a distant light source and the observer bends and magnifies the light from the source behind it. This allows astronomers to see objects that would otherwise be to faint to see.

[4] For each image of the supernova, the light is not bent in the same way. This results in slightly different travel times. The maximum time delay between the four images is predicted to be less than 35 hours.

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

This research was presented in a paper entitled “iPTF16geu: A multiply-imaged gravitationally lensed Type Ia supernova” by Goobar et al., which appeared in the journal Science.

The international team of astronomers in this study consists of A. Goobar (The Oskar Klein Centre, Sweden), R. Amanullah (The Oskar Klein Centre, Sweden), S. R. Kulkarni (Cahill Center for Astrophysics, USA), P. E. Nugent (University of California, USA; Lawrence Berkeley National Laboratory, USA), J. Johansson (Weizmann Institute of Science, Israel), C. Steidel (Cahill Center for Astrophysics, USA), D. Law (Space Telescope Science Institute, USA), E. Mörtsell (The Oskar Klein Centre, Sweden), R. Quimby (San Diego State University, USA; Kavli IPMU (WPI), Japan), N. Blagorodnova (Cahill Center for Astrophysics, USA), A. Brandeker (Stockholm University, Sweden), Y. Cao (eScience Institute and Department of Astronomy, USA), A. Cooray (University of California, USA), R. Ferretti (The Oskar Klein Centre, Sweden), C. Fremling (The Oskar Klein Centre, Sweden), L. Hangard (The Oskar Klein Centre, Sweden), M. Kasliwal (Cahill Center for Astrophysics, USA), T. Kupfer (Cahill Center for Astrophysics, USA), R. Lunnan (Cahill Center for Astrophysics, USA; Stockholm University, Sweden), F. Masci (Infrared Processing and Analysis Center, USA), A. A. Miller (Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), USA; The Adler Planetarium, USA) H. Nayyeri (University of California, USA), J. D. Neill (Cahill Center for Astrophysics, USA), E. O. Ofek (Weizmann Institute of Science, Israel), S. Papadogiannakis (The Oskar Klein Centre, Sweden), T. Petrushevska (The Oskar Klein Centre, Sweden), V. Ravi (Cahill Center for Astrophysics, USA), J. Sollerman (The Oskar Klein Centre, Sweden), M. Sullivan (University of Southampton, UK), F. Taddia (The Oskar Klein Centre, Sweden), R. Walters (Cahill Center for Astrophysics, USA), D. Wilson (University of California, USA), L. Yan (Cahill Center for Astrophysics, USA), O. Yaron (Weizmann Institute of Science, Israel).

Links:

heic1525: https://www.spacetelescope.org/news/heic1525/

heic1702: http://www.spacetelescope.org/news/heic1702/

Hubblecast 70: Peering around cosmic corners: http://www.spacetelescope.org/videos/hubblecast70a/

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Science paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1710/heic1710a.pdf

Caltech press release: http://www.caltech.edu/news/rare-brightening-supernovas-light-found-palomar-observatory-54795

Berkeley press release: http://cs.lbl.gov/news-media/news/2017/rare-supernova-discovery-ushers-in-new-era-for-cosmology/

Keck telescope: http://www.keckobservatory.org/

ESO’s Very Large Telescope (VLT): http://www.eso.org/public/teles-instr/paranal-observatory/vlt/

For images and more information about Hubble, visit:

http://hubblesite.org/
http://www.nasa.gov/hubble
http://www.spacetelescope.org/

Images, Animation, Text, Credits: NASA, ESA, Sloan Digital Sky Survey, W. M. Keck Observatory, Palomar Observatory/California Institute of Technology.

Best regards, Orbiter.ch