Astrophysicist / en Third detection of gravitational waves: ¸ŁŔűĽ§×ÔÎżscientists part of research team /news/third-detection-gravitational-waves-u-t-scientists-part-research-team <span class="field field--name-title field--type-string field--label-hidden">Third detection of gravitational waves: ¸ŁŔűĽ§×ÔÎżscientists part of research team</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2017-06-01-gravitational-waves_0.jpg?h=afdc3185&amp;itok=D1_-6It6 370w, /sites/default/files/styles/news_banner_740/public/2017-06-01-gravitational-waves_0.jpg?h=afdc3185&amp;itok=_O6jzrJK 740w, /sites/default/files/styles/news_banner_1110/public/2017-06-01-gravitational-waves_0.jpg?h=afdc3185&amp;itok=RRTbi0t6 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2017-06-01-gravitational-waves_0.jpg?h=afdc3185&amp;itok=D1_-6It6" alt="gravitational waves"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>ullahnor</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2017-06-01T12:10:56-04:00" title="Thursday, June 1, 2017 - 12:10" class="datetime">Thu, 06/01/2017 - 12:10</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">Illustration showing two merging black holes similar to those detected by LIGO. The black holes are spinning in a non-aligned fashion with different orientations (courtesy of LIGO/Caltech/MIT/Sonoma State/Aurore Simonnet)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/sean-bettam" hreflang="en">Sean Bettam</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Sean Bettam</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/global-lens" hreflang="en">Global Lens</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/faculty-arts-science" hreflang="en">Faculty of Arts &amp; Science</a></div> <div class="field__item"><a href="/news/tags/gravitational-waves" hreflang="en">Gravitational waves</a></div> <div class="field__item"><a href="/news/tags/space" hreflang="en">Space</a></div> <div class="field__item"><a href="/news/tags/astrophysicist" hreflang="en">Astrophysicist</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>It's the third time gravitational waves – ripples in space and time – have been detected, paving&nbsp;the way to more&nbsp;information about black holes and proving once again that Einstein was correct.</p> <p>The discovery announced today by the&nbsp;<a href="https://www.ligo.caltech.edu/">Laser Interferometer Gravitational-wave Observatory</a>&nbsp;(LIGO) would not have been possible without the key contributions of a team of ¸ŁŔűĽ§×ÔÎżastrophysicists.</p> <p>The newfound black hole has a mass about 49 times that of our sun and, at 3 billion light-years away from Earth, seems to be the farthest away to date.&nbsp;</p> <p>“With this latest detection of gravitational waves, we continue to learn that colliding black holes come in a variety of masses,” said <strong>Harald Pfeiffer</strong>, associate professor and Canada Research Chair in Gravitational Wave Astrophysics and Numerical Relativity&nbsp;at the <a href="http://www.cita.utoronto.ca/">Canadian Institute for Theoretical Astrophysics </a>(CITA) in U of T's Faculty of Arts &amp; Science. “These new black holes are the second-most massive stellar mass black holes ever detected, second only to our first LIGO discovery.”</p> <p>“The fact that this latest detection is so far away enables us to test Einstein’s equations more precisely than ever before&nbsp;and to perform different tests of Einstein’s equations for the very first time.”</p> <p>LIGO made the first-ever direct observation of gravitational waves in September 2015, followed by a second detection in December 2015. As with the previous discoveries, the latest gravitational waves were generated when two black holes collided and merged into a larger black hole.</p> <p>The black hole involved in the first detection was 62 times the mass of the sun and 1.3 billion light years away, while the one that figured in the second detection was 21 times the sun’s mass and 1.4 billion light years away.</p> <p>This third detection – called GW170104 and made on Jan.&nbsp;4, 2017 – is described in a new paper accepted for publication in the journal <em><a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.221101">Physical Review Letters</a>. </em>It was authored by&nbsp;the LIGO Scientific Collaboration (LSC), a body of more than 1,000 international scientists who perform LIGO research together with the Europe-based Virgo Collaboration.</p> <p>In all three detections, each of LIGO’s twin detectors – one in Livingston, La., and one in Hanford, Wash.,&nbsp;– picked up gravitational waves resulting from the tremendously energetic mergers of black hole pairs. These collisions produce more power than is radiated as light by all the stars and galaxies in the universe at any given time.</p> <p>Pfeiffer, who is also a fellow of the <a href="https://www.cifar.ca/">Canadian Institute for Advanced Research</a> (CIFAR), leads a team of seven researchers at ¸ŁŔűĽ§×ÔÎżthat constitutes Canada’s contribution to the LIGO project. The team had originally been largely responsible for performing simulations of black hole-collisions on high-performance supercomputers, and producing the gravitational waveforms – the shapes of the signals – that LIGO is searching. Having doubled in size over the past year, the team now includes researchers taking leading roles in estimating the masses and spins of the colliding black holes.</p> <p>“Knowing more about the ways black holes spin will teach us how binary black holes form and whether or not the rotation of each are aligned with their orbits,” said Pfeiffer.</p> <p>There are several models that explain how binary pairs of black holes can be formed, and the ongoing detections of gravitational waves will help scientists hone in on the best ones.</p> <p>The new LIGO data points to the possibility that at least one of the black holes may have been non-aligned compared to the overall orbital motion. While more observations with LIGO are needed to be definitive these early data offer clues about how these pairs may form.</p> <p><strong>Heather Fong</strong>, a PhD candidate in the department of physics and a member of Pfeiffer’s team at CITA, has played a key role in the development of the gravitational waveforms. Though she was instrumental in the process of simulating collisions of black holes that&nbsp;led to the first two detections, this latest event is particularly exciting for her, having recently spent three months at LIGO’s Hanford site.</p> <p>“I arrived just a week after we made this latest detection. Because I am mainly involved with the data analysis effort, it was amazing to be able to work on the experimental side and interact directly with the detector,” said Fong. “The time I spent there gave me a great deal of insight into how the LIGO detectors work, as well as a profound appreciation for how they're able to be as sensitive as they are.”</p> <p>The study once again puts Einstein's theories to the test. For example, the researchers looked for an effect called dispersion, which occurs when light waves in a physical medium such as glass travel at different speeds depending on their wavelength. This is how a prism creates a rainbow. Einstein's general theory of relativity forbids dispersion from happening in gravitational waves as they propagate from their source to Earth. LIGO did not find evidence for this effect.</p> <p>Pfeiffer believes that more results may also allow scientists to identify other unknown phenomena that are yet to be identified.</p> <p>“The other really important source of gravitational waves that everybody is eagerly waiting for are binary pairs involving neutron stars, whether they be two neutron stars or a black hole colliding with a neutron star,” he said. “Either way, these detections are continuously proving Einstein’s century-old theory of relativity is correct. And they are doing so with objects we didn’t know existed before LIGO detected them.</p> <p>LIGO is funded by the&nbsp;National Science Foundation&nbsp;(NSF), and operated by&nbsp;MIT&nbsp;and&nbsp;Caltech, which conceived and built the project. Financial support for the Advanced LIGO project was led by NSF with Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council) and Australia (Australian Research Council) making significant commitments and contributions to the project.</p> <p><a href="http://ligo.org/partners.php">More than 1,000 scientists from around the world</a> participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration. LIGO partners with the&nbsp;Virgo Collaboration, a consortium including 280 additional scientists throughout Europe supported by the&nbsp;Centre National de la Recherche Scientifique&nbsp;(CNRS), the&nbsp;Istituto Nazionale di Fisica Nucleare&nbsp;(INFN), and&nbsp;Nikhef, as well as Virgo’s host institution, the European Gravitational Observatory.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 01 Jun 2017 16:10:56 +0000 ullahnor 108018 at Planets in TRAPPIST-1 orbiting in synchronized harmonies, ¸ŁŔűĽ§×ÔÎżastrophysicist and musicians discover /news/planets-trappist-1-orbiting-synchronized-harmonies-u-t-astrophysicist-and-musicians-discover <span class="field field--name-title field--type-string field--label-hidden">Planets in TRAPPIST-1 orbiting in synchronized harmonies, ¸ŁŔűĽ§×ÔÎżastrophysicist and musicians discover</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2017-05-10-tamayo-TRAPPIST1.jpg?h=afdc3185&amp;itok=NmhivPI3 370w, /sites/default/files/styles/news_banner_740/public/2017-05-10-tamayo-TRAPPIST1.jpg?h=afdc3185&amp;itok=AQ9EEaM3 740w, /sites/default/files/styles/news_banner_1110/public/2017-05-10-tamayo-TRAPPIST1.jpg?h=afdc3185&amp;itok=4PzwjQGk 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2017-05-10-tamayo-TRAPPIST1.jpg?h=afdc3185&amp;itok=NmhivPI3" alt="TRAPPIST-1"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>ullahnor</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2017-05-10T12:11:32-04:00" title="Wednesday, May 10, 2017 - 12:11" class="datetime">Wed, 05/10/2017 - 12:11</time> </span> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/don-campbell" hreflang="en">Don Campbell</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Don Campbell</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/astrophysicist" hreflang="en">Astrophysicist</a></div> <div class="field__item"><a href="/news/tags/u-t-scarborough" hreflang="en">¸ŁŔűĽ§×ÔÎżScarborough</a></div> <div class="field__item"><a href="/news/tags/planets" hreflang="en">Planets</a></div> <div class="field__item"><a href="/news/tags/trappist-1" hreflang="en">TRAPPIST-1</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">They have created a digital symphony to highlight the unique configuration which saves TRAPPIST-1 from destruction</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>NASA's discovery of the TRAPPIST-1 planetary system earlier this year&nbsp;created excitement after three planets were found to be in the star's habitable zone. But it also created confusion since the system appeared to be highly unstable, in danger of&nbsp;smashing itself to bits.</p> <p>Now a ¸ŁŔűĽ§×ÔÎżastrophysicist&nbsp;may have helped solve&nbsp;that puzzle – with&nbsp;jazz music and animation.&nbsp;</p> <p><strong>Dan Tamayo</strong>, a postdoc researcher at ¸ŁŔűĽ§×ÔÎżScarborough’s Centre for Planetary Science, fellow astrophysicist Matt Russo, who plays jazz, and musician&nbsp;Andrew Santaguida teamed up with a Toronto-based animation studio to illustrate the planetary system's&nbsp;remarkable configuration. Speeding up the planets’ orbital frequencies into the human hearing range, they've created&nbsp;an astrophysical symphony of sorts, playing out more than 40 light years away.&nbsp;</p> <h3><a href="https://www.nytimes.com/2017/05/10/science/trappist-earth-size-planets-orbits-music.html">Read more at <em>The New York Times</em></a></h3> <p>&nbsp;</p> <p><iframe allowfullscreen frameborder="0" height="500" src="https://www.youtube.com/embed/7i8Urhbd6eI" width="750"></iframe></p> <p>In research published in the journal<em> <a href="http://iopscience.iop.org/article/10.3847/2041-8213/aa70ea">Astrophysical Journal Letters</a></em>, the scientists&nbsp;describe the planets in the TRAPPIST-1 system as being in something called a “resonant chain” that strongly stabilizes it.&nbsp;</p> <p>The scientists who originally discovered the planetary system found it to be unstable,&nbsp;with simulations in their discovery paper showing the planets “crashing&nbsp;into one another in less than a million years.”&nbsp;</p> <p>“This may seem like a long time, but it’s really just an astronomical blink of an eye,” says Tamayo. &nbsp;“It would be very lucky for us to discover TRAPPIST-1 right before it fell apart&nbsp;so there must be a reason why it remains stable.”</p> <p>In resonant configurations, planets’ orbital periods form ratios of whole numbers. For example,&nbsp;Neptune orbits the sun three times in the amount of time it takes Pluto to orbit twice. This is good for Pluto because otherwise it wouldn’t exist. With the two planets’ orbits intersecting, if things were random they would eventually collide. But because of resonance, the locations of the planets relative to one another keeps repeating.</p> <p>TRAPPIST-1 takes this principle to a whole other level with all seven planets being in a chain of resonances.</p> <p>Tamayo, Russo&nbsp;and Santaguida created the&nbsp;animation, showing that the planets play a piano note every time they pass in front of their host star, and a drum beat every time a planet overtakes its nearest neighbour.&nbsp;</p> <p><img alt class="media-image attr__typeof__foaf:Image img__fid__4560 img__view_mode__media_original attr__format__media_original" src="/sites/default/files/2017-05-10-tamayo.jpg" style="width: 750px; height: 500px; margin: 10px;" typeof="foaf:Image"><br> <em>Dan Tamayo, a postdoc researcher at ¸ŁŔűĽ§×ÔÎżScarborough, and a fellow astrophysicist&nbsp;have helped simulate what keeps the TRAPPIST-1 system stable (photo by Ken Jones)&nbsp;</em></p> <p>“There’s a rhythmic repeating pattern that ensures the system remains stable over a long period of time,” says Russo, who thought the TRAPPIST-1 resonances looked familiar from music theory.&nbsp;</p> <p>Because the planets’ periods are simple ratios of each other, their motion creates a steady repeating pattern that is similar to how we play music. Simple frequency ratios are also what makes two notes sound pleasing when played together.</p> <p>“Most planetary systems are like bands of amateur musicians playing their parts at different speeds,” says Russo. “TRAPPIST-1 is different. It’s a super-group with all seven members synchronizing their parts in nearly perfect time.”</p> <p>But as Tamayo notes, even synchronized orbits don’t necessarily survive very long. For technical reasons, chaos theory also requires precise orbital alignments to ensure solar systems remain stable. This can explain why the simulations done in the original discovery paper quickly resulted in the planets colliding with one another.</p> <p>“It's not that the system is doomed, it’s that stable configurations are very exact,” he says. “We can't measure all the orbital parameters well enough at the moment&nbsp;so the simulated systems kept resulting in collisions because the setups weren’t precise.”&nbsp;</p> <p>In order to overcome this, Tamayo and his team looked at the system not as it is today, but how it may have originally formed. When the system was being born out of a disk of gas, the planets should have migrated relative to one another, allowing the system to naturally settle into a stable resonant configuration. &nbsp;</p> <p>“This means that early on, each planet's orbit was tuned to make it harmonious with its neighbours, in the same way that instruments are tuned by a band before it begins to play,”&nbsp;says Russo. “That’s why the animation produces such beautiful music.”</p> <p>The team tested the simulations using the supercomputing cluster at the Canadian Institute for Theoretical Astrophysics (CITA) and found that the majority they generated remained stable for as long as they could possibly run it. This was about 100 times longer than it took for the simulations in the original research paper describing TRAPPIST-1 to go berserk.</p> <p>“It seems somehow poetic that this special configuration that can generate such remarkable music can also be responsible for the system surviving to the present day,” says Tamayo.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Wed, 10 May 2017 16:11:32 +0000 ullahnor 107498 at