ASU researcher involved in groundbreaking detection of neutron star collision

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The scientific community is excited about a recent collision between two neutron stars. For the first time ever, light emitted from an event that created gravitational waves was observed when those two stars collided.

Arizona State University astronomer Nathaniel Butler is part of a team of astronomers that used ground and space-based telescopes to pinpoint the source of the gravitational waves emitted by the collision, which were picked up by the Laser Interferometer Gravitational Wave Observatory, or LIGO.

Butler tells us why this is such an important discovery and how the neutron star collision created massive amounts of heavy metals, including huge amounts of gold.

TED SIMONS: COMING UP NEXT ON ARIZONA HORIZON. DETAILS ON A MAJOR DISCOVERY IN SPACE AS SCIENTISTS WITNESS 2 NEUTRON STARS COLLIDING... ALSO TONIGHT: WHY EMPLOYEES FEEL PRESSURED TO CHEAT IN THE WORKPLACE. AND AFTER 18-SEASONS AND 3 GRAMMY AWARDS THE ARTISTIC DIRECTOR OF THE PHOENIX CHORALE IS STEPPING DOWN. THOSE STORIES NEXT ON ARZIONA HORIZON.

VIDEO: ARIZONA "HORIZON" IS MADE POSSIBLE BY CONTRIBUTIONS FROM THE FRIENDS OF ARIZONA PBS, MEMBERS OF YOUR PBS STATION. THANK YOU.

TED SIMONS: GOOD EVENING AND WELCOME TO ARIZONA HORIZON. I'M TED SIMONS. THE PBS NEWSHOUR'S JUDY WOODRUFF AND THE LATE GWEN IFILL WERE HONORED TODAY WITH THE CRONKITE AWARD FOR EXCELLENCE IN JOURNALISM. THE ANNUAL CEREMONY DREW HUNDREDS TO DOWNTOWN PHOENIX. WOODRUFF AND IFILL WERE THE FIRST FEMALE CO-ANCHORS OF A NATIONAL EVENING NEWSCAST. GWEN IFILL PASSED AWAY LAST YEAR. HER BROTHER ACCEPTED THE HONOR TODAY. AS FOR JUDY WOODRUFF, HER SPEECH INCLUDED A RESPONSE TO PRESIDENT TRUMP'S ATTACKS ON THE PRESS.

VIDEO: SO HE IS COMFORTABLE TALKING TO AND TAKING ON REPORTERS AND ENTIRE NEWS ORGANIZATIONS. HE BUILT A CAMPAIGN AND NOW AN ADMINISTRATION BY CALLING MOST NEWS "FAKE" AND MOST JOURNALISTS ENEMIES OF THE AMERICAN PEOPLE. I AM NOT AN ENEMY OF THE AMERICAN PEOPLE. THAT IS NOT TRUE. [APPLAUSE] I LOVE THIS COUNTRY. I LOVE THIS COUNTRY.

TED SIMONS: THIS IS THE 34TH YEAR OF THE CRONKITE AWARD.
TED SIMONS: A RECENT COLLISION BETWEEN 2 NEUTRON STARS IS CAUSING A LOT OF EXCITEMENT IN THE WORLD OF SCIENCE, THIS BECAUSE IT'S THE 1ST TIME ASTRONOMERS WERE ABLE TO SEE THE GRAVITATIONAL WAVES AND ELECTROMAGNETIC LIGHTNING CREATED BY THE COLLISION. ASU ASTRONOMER NATHANIEL BUTLER WAS ONE OF A NUMBER OF SCIENTISTS THAT TOOK PART IN THE DISCOVERY. HE JOINS US NOW. WELCOME TO ARIZONA "HORIZON." CONGRATULATIONS ON THIS. TWO NEUTRON STARS COLLIDING. TAKE US THROUGH THIS. WHAT HAPPENED OUT THERE? THIS HAPPENED 130 MILLION YEARS AGO?

NATHANIEL BUTLER: IT DID AND WE ARE JUST SEEING IT NOW. IN THAT GALAXY, 130 MILLION OR SO YEARS AWAY, TWO MASSIVE STARS EVOLVED AND LEFT BEHIND CORES, NEUTRON STARS. DUE TO THE EFFECTS OF GENERAL ACTIVITY, GRADUALLY SHRUNK IN ORBIT AND EVENTUALLY COLLIDED AND EXPLODED.

TED SIMONS: WE HAVE AN ANIMATION HERE. WALK US THROUGH WHAT WE ARE LOOKING AT. WHAT WE’RE GOING TO SEE ARE THESE TWO NEUTRON STARS CIRCLING, BUT AS THEY CIRCLE, THE GRAVITY BASICALLY FALLS IN ON ITSELF, RIGHT?

NATHANIEL BUTLER: YEAH. THIS IS AN EFFECT THAT WOULDN’T HAPPEN IN NEWTONIAN GRAVITY. WITH EINSTEIN'S THEORY GENERAL RELATIVITY, THE SYSTEM LOSES ANGULAR MOMENTUM AND THE TWO STARS SPIRAL IN AND EVENTUALLY TOUCH AND BLOW UP.

TED SIMONS: AND WHEN THEY TOUCH AND BLOW UP, THEN ALL YOU-KNOW-WHAT BREAKS LOOSE.

NATHANIEL BUTLER: IT GETS MESSY.

TED SIMONS: THIS ISN'T NECESSARILY A BIG DEAL, THE BIG DEAL IS WE SAW IT.

NATHANIEL BUTLER: THESE TWO STARS WHEN THEY SPIRALED INTO EACH OTHER, WHEN THEY POPPED, WHEN THEY FELL INTO EACH OTHER, THEY EMITTED GRAVITATIONAL WAVES. WITH MASSIVE DETECTORS ON THE EARTH IN WASHINGTON STATE, LOUISIANA AND NEAR PISA, ITALY WE SENSED THE RIPPLE IN SPACE FROM THAT COLLAPSE. THAT ALLOWED US TO KNOW WHERE IN THE SKY THE RIPPLE HAPPENED, TO PINPOINT THE GALAXY WHERE IT HAPPENED. AT THE SAME TIME THERE WAS A PULSE OF GAMMA RAYS IN THE SKY AND WE FOLLOWED THAT UP WITH LARGE TELESCOPES ON EARTH AND IN SPACE AND MONITORED FOR A MONTH THE EMBERS AND WRECKAGE FROM THAT EXPLOSION.

TED SIMONS: SO THE GRAVITATIONAL WAVES ARE DETECTED BY THIS BLIP AND THEN A FEW SECONDS LATER COMES THE FLASH?

NATHANIEL BUTLER: THAT IS ABOUT IT. THESE GRAVITATIONAL WAVES ARE LIKE A CHIRP, LIKE A SOUND WAVE THAT LASTS ABOUT A MINUTE IN THIS CASE. TWO SECONDS AFTER THAT CHIRP THERE WAS A FLASH OF GAMMA RAYS, A VERY FAST FLASH OF GAMMA RAYS, WHICH IS ANOTHER SIGNATURE OF THIS EXPLOSION. THIS NEUTRON STAR EXPLODING. AND IN ABOUT A DAY, THE OPTICAL LIGHT YOU SEE WITH TELESCOPES AND YOUR EYES BRIGHTENED UP AND GRADUALLY FADED OVER THE NEXT MONTH OR SO.

TED SIMONS: HOW DO YOU KNOW IT IS NOT SOMEONE RATTLING A POT OR PAN ACROSS THE STREET? LITTLE DRAMATIC THERE BUT HOW DO YOU KNOW THAT GRAVITATIONAL CHIP IS WHAT THAT CHIRP IS SUPPOSED TO BE.

NATHANIEL BUTLER: THAT IS A GREAT QUESTION. IT IS NOT SUCH A STRANGE ANALOGY. THESE DETECTORS ARE SO SENSITIVE IF A TRUCK DRIVES BY THEY CAN PICK UP A SIGNAL. AND SO WHAT IT TAKES FOR ASTRONOMERS TO BELIEVE IT IS TO HAVE A SIGNAL OF THE RIGHT SHAPE AND THEN TO BE ABLE TO POINT OUR TELESCOPES AND FIND SOMETHING AND TO ESTABLISH THIS IS REALLY A NEUTRON STAR EXPLODING. THIS IS AN ASTROPHYSICAL EVENT. IT WAS THE LIGHT YOU MENTIONED EARLIER.

TED SIMONS: THIS HADN'T BEEN DETECTED BEFORE BECAUSE?

NATHANIEL BUTLER: TECHNOLOGICALLY IT IS EXTREMELY DIFFICULT. THESE DETECTORS ARE JUST COMING ONLINE. THE ONE IN ITALY JUST CAME ONLINE BEFORE THIS DISCOVERY. NOW WE HAVE THE CAPABILITY AND WE’RE OPENING UP AN ENTIRE NEW WINDOW INTO THE UNIVERSE.

TED SIMONS: THIS IS BIG NEWS IN THE SCIENCE WORLD. WHY IS THIS SUCH BIG NEWS?

NATHANIEL BUTLER: IT HAS BEEN IN THE MAKING FOR A CENTURY AND PREDICTED SINCE THE LAST CENTURY AND IT’S BEEN AN EFFORT ON THE PARTS OF MANY NATIONS AND GENERATIONS OF SCIENTISTS TO BUILD THESE DETECTORS. THERE IS A WHOLE COMMUNITY AROUND THE WORLD THAT CHASES THESE DETECTIONS FROM THE GROUND WITH TELESCOPE AND IT HAS WORKED. YOU HAVE A WHOLE NEW WINDOW IN THE UNIVERSE AND WE KNOW GRAVITATIONAL WAVES ARE REAL, WE’RE SEEING THOSE, AND WE KNOW NEUTRON STARS COLLIDE AND EXPLODE.

TED SIMONS: HOW OFTEN DO NEUTRON STARS COLLIDE AND EXPLODE? WILL WE BE SEEING MORE?

NATHANIEL BUTLER: WE HOPE SO. THE SORT OF PULSE OF GAMMA RAYS THAT IS ASSOCIATED WITH THESE EXPLOSIONS HAPPENS ABOUT ONCE A DAY, IT’S A COMMON EVENT. NEUTRON STARS, MOST MASSIVE STARS, COULD GO TO NEUTRON AND MOST ARE IN BINARIES AND COULD BE IN PAIRS. IT SHOULD BE A RECURRENCE IN NATURE AND WE KNOW IT HAS TO BE BECAUSE LARGE PARTS OF THE PERIODIC TABLE CONTAIN THINGS WITH LARGE NUCLEI AND WE THINK THOSE NUCLEI ARE BUILT UP BY THESE STARS. THINGS LIKE GOLD, PLATINUM, SILVER, MANY PRECIOUS METALS. IT HAS BEEN A MYSTERY FOR A WHILE WHERE THEY COME FROM AND HOW THE UNIVERSE MAKES THEM BUT NEUTRON STARS HAVE BEEN A POPLAR THEORETICAL IDEA AND NOW WE HAVE EVIDENCE FOR THAT.

TED SIMONS: IF THIS HAPPENS NEXT MONTH YOU WON'T BE TOO SURPRISED BECAUSE IT HAS BEEN DONE BEFORE.

NATHANIEL BUTLER: I WILL BE DELIGHTED IF THIS HAPPENS NEXT MONTH. IF THIS HAPPENS NEXT WEEK AND EVERY WEEK FROM THERE ON OUT IT IS A WHOLE NEW INDUSTRY, IT’S A WHOLE NEW UNIVERSE TO EXPLORE.

TED SIMONS: FROM 130 LIGHT YEARS AWAY IT SEEMS LIKE SOMETHING MIGHT HAVE HAPPENED 75 OR 95 AND WE SHOULD BE SEEING MORE OF THAT.

NATHANIEL BUTLER: I AGREE. THESE COULD BE DETECTED TO MUCH GREATER DISTANCES. MAYBE 10 TIMES FURTHER AWAY. IF THIS DETECTION CONTINUES WE MAY SEE 100 TIMES MORE OF THESE.

TED SIMONS: WHAT WILL WE LEARN BY ALL THIS?

NATHANIEL BUTLER: WE WILL CONTINUE TO LEARN WHERE THE STUFF WE’RE MADE OF COMES FROM AND WHETHER YOUR OTHER QUESTION IS CORRECT THAT WE CAN UNDERSTAND WHERE THOSE MATERIALS COME FROM AND ATTRIBUTE THEM TO THOSE EXPLOSIONS AND UNDERSTAND THIS KIND OF EXPLOSION CALLED A KILONOVA WHICH IS A 1,000 TIMES BRIGHTER THAN A TYPICAL NOVA WHICH WE THINK IS NORMAL IN NATURE. WE WILL STUDY THOSE IN DETAIL AND WE’LL KNOW A LOT ABOUT GAMMA RAY BURSTS WHICH ARE EXOTIC EXPLOSIONS WE HAVE BEEN MONITORING SINCE THE 1960s WHICH ARE AMAZING.

TED SIMONS: CONGRATULATIONS ON BEING PART OF THIS. THIS MUST BE VERY EXCITING FOR YOU AND QUITE A COUP. GOOD LUCK ON HUNTING THIS STUFF IN THE FUTURE. UP NEXT ON ARIZONA HORIZON, WHY WORKERS ARE INCREASINGLY BENDING THE RULES ON THE JOB.

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