- Cillian Murphy Reacts To Matt Damon Calling Him The ‘Worst Dinner Companion Imaginable’ HuffPost
- Cillian Murphy understands why Matt Damon called him the ‘worst dinner companion imaginable’ CNN
- Actor Cillian Murphy on acting and his first reaction to reading the “Oppenheimer” script CBS News
- ‘Awards Chatter’ Podcast: Cillian Murphy on ‘Oppenheimer,’ Potential ‘Peaky Blinders’ Movie and Making a Musical Hollywood Reporter
- Cillian Murphy Explains Why Matt Damon Called Him the ‘Worst Dinner Companion’ PEOPLE
Tag Archives: Companion
Cillian Murphy Reacts To Matt Damon Calling Him The ‘Worst Dinner Companion Imaginable’ – HuffPost
- Cillian Murphy Reacts To Matt Damon Calling Him The ‘Worst Dinner Companion Imaginable’ HuffPost
- Cillian Murphy understands why Matt Damon called him the ‘worst dinner companion imaginable’ CNN
- Actor Cillian Murphy on acting and his first reaction to reading the “Oppenheimer” script CBS News
- ‘Awards Chatter’ Podcast: Cillian Murphy on ‘Oppenheimer,’ Potential ‘Peaky Blinders’ Movie and Making a Musical Hollywood Reporter
- How Cillian Murphy became ‘the greatest actor of his generation’ The Telegraph
Cillian Murphy understands why Matt Damon called him the ‘worst dinner companion imaginable’ – CNN
- Cillian Murphy understands why Matt Damon called him the ‘worst dinner companion imaginable’ CNN
- Cillian Murphy Explains Why Matt Damon Called Him the ‘Worst Dinner Companion’ PEOPLE
- Actor Cillian Murphy on acting and his first reaction to reading the “Oppenheimer” script CBS News
- ‘Awards Chatter’ Podcast: Cillian Murphy on ‘Oppenheimer,’ Potential ‘Peaky Blinders’ Movie and Making a Musical Hollywood Reporter
- Cillian Murphy Reacts To Matt Damon Calling Him The ‘Worst Dinner Companion Imaginable’ HuffPost
This small Bluetooth dongle is now my essential travel and road trip companion
Rita El Khoury / Android Authority
Flights are boring, longer ones even more so. Since I have picky ears that despise nearly every earbud shape or size, I’ve often struggled with the default in-plane entertainment options. For the past few years, I’ve resorted to downloading some podcasts and playlists and listening to them with my own tried-and-tested comfortable Bluetooth buds. It’s a minimalistic setup, but it works for me and allows me to skip cramming a tablet or laptop in the small space in front of me.
Glancing at my husband next to me, though, I still envied how he could simply grab any plane-provided earbud or headset and use it with the in-flight entertainment system. On our four-hour trips back home to Lebanon, he can catch two movies, while I struggle to pass the time after the second or third hour.
Audio can only go so far to distract me on a multi-hour flight. Movies are better time-wasters.
Then, as I was preparing for my transatlantic flight to Toronto last month, I realized I needed a solution to help those seven-plus hours pass. In my search for solutions, I came across the AirFly Pro, and now that I’ve used it on a few flights, I have to say it’s easily the neatest and most versatile little travel gadget.
Rita El Khoury / Android Authority
Most airplanes nowadays have a 3.5mm headset output and airlines provide you with a pair of cheap, single-use earbuds to plug in. Some older planes might have the two-prong output (though it’s been a few years since I personally came across those), while newer ones might offer pre-plugged headphones.
The AirFly Pro only works when there’s a 3.5mm jack. It plugs directly into the in-flight entertainment system and lets you transmit audio to your own Bluetooth headphones or buds. One button turns it on and puts it in pairing mode, and all you have to do is make sure your headset is in pairing mode too for them to find each other and connect.
I plugged it into the audio output of the plane and enjoyed a movie on my own Bluetooth buds.
I tested it with both my Google Pixel Buds Pro and Nothing Ear 1, and it worked like a charm. In a few seconds, I was watching a movie on the headrest display in front of me without sacrificing my ears’ comfort. And without wearing Air France’s terrible-sounding on-ear headphones, which have been on countless heads before mine. (I later took another flight where they provided those single-use buds and avoided those too — less e-waste, more comfortable ears, a win-win for all.)
Rita El Khoury / Android Authority
The best part is that the Pixel Buds Pro can connect to two devices at the same time, so I could easily switch from watching a movie on the plane’s display (with the AirFly Pro) to listening to some music or catching a video on my phone, without taking my buds out, pressing any button, or plugging/unplugging anything. This isn’t a Buds Pro-only feature, though — look for headphones or buds that offer “Multipoint” functionality and you can have a similarly seamless experience.
Beyond planes, this can add Bluetooth output to older TVs and game consoles, iPods, and gym equipment.
Back to the dongle, now. It can do so much more. I’m focusing on the travel experience, but you can basically use this to turn anything with a 3.5mm headset output into a wireless device. Gym equipment, an iPod Nano or Classic, an older TV or game console; the list goes on.
There’s also a splitter functionality that lets you route the audio to two Bluetooth headsets at the same time, so you could watch the same thing with a friend, sibling, or partner in a public place and still enjoy the isolation of your own individual headphones/buds.
Rita El Khoury / Android Authority
But there’s another side to the equation too. See that small TX-RX toggle on the side of the AirFly Pro? Move it to the RX position to completely change how the dongle works.
Now it’s a Bluetooth receiver. Plug it into the auxiliary input jack of any car or speaker and it will catch and play any audio from an emitting device like your phone, tablet, or computer. So versatile.
One flick and it transforms into a Bluetooth receiver for any car or speaker. Perfect for road trips.
During my Canadian trip, I used the dongle in receiver mode in our rental cars to play my favorite tunes. Again, one button press let me pair it to my Pixel 6 Pro. I didn’t have to figure out the Bluetooth pairing process of each car, I just paired once with the dongle and plugged it into the cars. I kind of regret not having tried a solution like this with my old Subaru XV. That car had the most fickle Bluetooth connection and failed to see my phone four times out of five; a Bluetooth receiver like this would have let me bypass that entirely.
Despite its tiny size, the AirFly Pro’s battery lasts about 16 hours. It handled a seven-hour flight, a few hours of driving, then almost lasted through the same seven-hour flight back. And when it was empty, I just charged it over USB-C and it was ready to go.
If you don’t care about the receiver feature, you can save a few bucks by picking a more basic AirFly version. These are the options offered now:
- The AirFly ($34.99) is just a Bluetooth transmitter and can only pair with one set of headphones at a time.
- The AirFly Duo ($44.99) adds the option to pair and listen on two Bluetooth headsets simultaneously.
- The AirFly Pro ($54.99) does all of the above and acts as a receiver too.
- A discontinued AirFly USB-C (still sold by third-party vendors for $60 or above) was basically the same as the Duo but with a USB-C plug instead of the 3.5mm jack.
The Pro makes the most sense for my usage, but I wish it came with a USB-C converter in the box to let me use it on my Android phones and iPad too.
Rita El Khoury / Android Authority
It’s incredibly convenient to have my setup ready to go on any flight and in any car.
Was the AirFly Pro essential in any of the situations where I tried it? No, of course not. But it was incredibly convenient to get on a flight or in a car and know I had my own setup ready to go. And it’s so tiny and portable too. That’s why it has rightfully earned a permanent spot in my travel bag.
AirFly Pro
Great on airplanes • Works in cars • USB-C charging
A versatile dongle that lets you use your own Bluetooth headset on planes and more
The AirFly Pro is a dual-mode Bluetooth dongle. In Transmit mode, it can share audio from any device (including planes) to a pair of Bluetooth buds or headphones. In Receive mode, it can be plugged into a car or speakers to receive audio from a phone or tablet. It charges over USB-C and lasts 16 hours on a charge.
Dead stars in Milky Way’s companion galaxy cause gamma-ray cocoon
Mysterious ultrabright gamma-ray emissions in the giant bubbles blown out by our galaxy may finally have an explanation.
Researchers used data from the Gaia and Fermi space telescopes to search through the Fermi bubbles, a pair of colossal hourglass-shaped bubbles that extend from the poles of the Milky Way and span 50,000 light-years, to trace the source of the very bright gamma-ray emission spots.
They discovered that one of the brightest of these spots, dubbed the “Fermi cocoon,” located in the southern bubble, was caused by emissions from rapidly spinning dead stars called pulsars in the Milky Way’s satellite galaxy Sagittarius. The finding could shed light on how these collapsed dead stars act as cosmic particle accelerators, blasting out high-energy particles that go on to cause gamma-ray emissions.
Related: Astronomers spot the brightest intergalactic pulsar yet beyond the Milky Way
Gamma-rays have previously been highlighted as a possible result of dark matter annihilation. But if gamma-rays are the result of particles accelerated by pulsars, they may not be evidence of dark matter.
The Sagittarius dwarf satellite galaxy is viewed from Earth through the Fermi bubbles and is marked by elongated streams of gas and stars that were ripped from the galaxy’s core as its tight orbit threaded it through the disk of the Milky Way.
Gamma-ray emissions are thought to be created by young stars, by dark matter annihilation or by millisecond pulsars. This violent gas removal means that the Sagittarius dwarf galaxy is no longer forming stars and lacks stellar nurseries, so its gamma-ray emissions can’t be the result of young stars.
Furthermore, the shape of the Fermi cocoon closely matches the observed distribution of visible stars, ruling out dark matter as a source of the emissions. (If dark matter were present, its gravity would affect the shape of the cocoon). Thus, the researchers concluded that the only possible sources of this powerful radiation were a hitherto unknown population of millisecond pulsars, which are rapidly rotating, ultradense stellar remnants that spin hundreds of times per second.
“We are satisfied there is only one possibility: rapidly spinning objects called ‘millisecond pulsars,'” the team wrote in an Australian National University statement (opens in new tab). “Millisecond pulsars in the Sagittarius dwarf were the ultimate source of the mysterious cocoon, we found.”
Like all neutron stars, a pulsar forms when a star much more massive than the sun reaches the end of its life and can no longer carry out nuclear fusion in its core. As a result, it can no longer support itself against complete gravitational collapse. Accompanied by a massive supernova blast, the gravitational collapse leaves behind a city-size star with a mass around that of the sun. This stellar remnant is composed of matter so dense that a teaspoon of it would weigh 4 billion tons.
Scientists think millisecond pulsars’ rapid rotation is caused by the accretion of matter from a binary companion star that adds angular momentum to the dead star — or “spins it up.”
Due to their powerful magnetic fields, the poles of pulsars blast out electrons and positrons (electrons’ antimatter equivalents). When the electrons interact with low-energy photons that make up the cosmic microwave background (CMB) — radiation left over from shortly after the Big Bang — the electrons impart some of their kinetic energy. This causes CMB photons to become much more energetic gamma-ray photons.
By demonstrating that the gamma-ray cocoon is the result of pulsars, the team’s results suggest that the gamma-ray emissions in the Fermi bubbles are not the result of dark matter annihilation, the researchers said.
“This is significant because dark matter researchers have long believed that an observation of gamma rays from a dwarf satellite would be a smoking-gun signature for dark matter annihilation,” team co-leader Oscar Macias, a researcher at the University of Amsterdam, said in a statement. (opens in new tab) “Our study compels a reassessment of the high energy emission capabilities of quiescent stellar objects, such as dwarf spheroidal galaxies, and their role as prime targets for dark matter annihilation searches.”
The team’s research was published online Sept. 5 in the journal Nature Astronomy (opens in new tab).
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This Record-Breaking ‘Black Widow’ Pulsar Is The Most Massive Neutron Star Yet
One of the most extreme stars in the Milky Way just got even more wack.
Scientists have measured the mass of a neutron star named PSR J0952-0607, and found that it’s the most massive neutron star discovered yet, clocking in at a whopping 2.35 times the mass of the Sun.
If true, this is very close to the theorized upper mass limit of around 2.3 solar masses for neutron stars, representing an excellent laboratory for studying these ultra-dense stars at what we think is the brink of collapse, in the hope of better understanding the weird quantum state of the matter of which they are made.
“We know roughly how matter behaves at nuclear densities, like in the nucleus of a uranium atom,” said astrophysicist Alex Filippenko of the University of California, Berkeley.
“A neutron star is like one giant nucleus, but when you have one-and-a-half solar masses of this stuff, which is about 500,000 Earth masses of nuclei all clinging together, it’s not at all clear how they will behave.”
Neutron stars are the collapsed cores of massive stars that were between around 8 and 30 times the mass of the Sun, before they went supernova and blew most of their mass off into space.
These cores, tending to be around 1.5 times the mass of the Sun, are among the densest objects in the Universe; the only thing denser is a black hole.
Their mass is packed into a sphere just 20 kilometers (12 miles) or so across; at that density, protons and electrons can combine into neutrons. The only thing keeping this ball of neutrons from collapsing into a black hole is the force it would take for them to occupy the same quantum states, described as degeneracy pressure.
In some ways this means neutron stars behave like massive atomic nuclei. But what happens at this tipping point, where neutrons form exotic structures or blur into a soup of smaller particles, is hard to say.
PSR J0952-0607 was already one of the most interesting neutron stars in the Milky Way. It’s what is known as a pulsar – a neutron star that is spinning very fast, with jets of radiation emitting from the poles. As the star spins, these poles sweep past the observer (us) in the manner of a cosmic lighthouse so that the star appears to pulse.
These stars can be insanely fast, their rotation rate on millisecond scales. PSR J0952-0607 is the second-fastest pulsar in the Milky Way, rotating a mind-blowing 707 times per second. (The fastest is only slightly faster, with a rotation rate of 716 times per second.)
It’s also what is known as a “black widow” pulsar. The star is in a close orbit with a binary companion – so close that its immense gravitational field pulls material from the companion star. This material forms an accretion disk that whirls around and feeds into the neutron star, a bit like water swirling around a drain. Angular momentum from the accretion disk is transferred to the star, causing its spin rate to increase.
A team led by astrophysicist Roger Romani of Stanford University wanted to understand better how PSR J0952-0607 fit into the timeline of this process. The binary companion star is tiny, less than 10 percent of the mass of the Sun. The research team made careful studies of the system and its orbit and used that information to obtain a new, precise measurement for the pulsar.
Their calculations returned a result of 2.35 times the mass of the Sun, give or take 0.17 solar masses. Assuming a standard neutron star starting mass of around 1.4 times the mass of the Sun, that means that PSR J0952-0607 has slurped up to an entire Sun’s worth of matter from its binary companion. This, the team says, is really important information to have about neutron stars.
“This provides some of the strongest constraints on the property of matter at several times the density seen in atomic nuclei. Indeed, many otherwise popular models of dense-matter physics are excluded by this result,” Romani explained.
“A high maximum mass for neutron stars suggests that it is a mixture of nuclei and their dissolved up and down quarks all the way to the core. This excludes many proposed states of matter, especially those with exotic interior composition.”
The binary also shows a mechanism whereby isolated pulsars, without binary companions, can have millisecond rotation rates. J0952-0607’s companion is almost gone; once it’s entirely devoured, the pulsar (if it’s not tipped over the upper mass limit and collapses further into a black hole) will retain its insanely fast rotation speed for quite some time.
And it will be alone, just like those all the other isolated millisecond pulsars.
“As the companion star evolves and starts becoming a red giant, material spills over to the neutron star, and that spins up the neutron star. By spinning up, it now becomes incredibly energized, and a wind of particles starts coming out from the neutron star. That wind then hits the donor star and starts stripping material off, and over time, the donor star’s mass decreases to that of a planet, and if even more time passes, it disappears altogether,” Filippenko said.
“So, that’s how lone millisecond pulsars could be formed. They weren’t all alone to begin with – they had to be in a binary pair – but they gradually evaporated away their companions, and now they’re solitary.”
The research has been published in The Astrophysical Journal Letters.
Heaviest neutron star results after devouring companion star
Called a neutron star, the dense, collapsed remnants of a massive star weighs more than twice the mass of our sun, making it the heaviest neutron star known to date. The object spins 707 times per second, which also makes it one of the fastest-spinning neutron stars in the Milky Way.
The neutron star is known as a black widow because, much like these arachnids known for female spiders that consume much smaller male partners after mating, the star has shredded and devoured almost the entire mass of its companion star.
This stellar feast has allowed the black widow to become the heaviest neutron star observed so far.
Astronomers were able to weigh the star, called PSR J0952-0607, by using the sensitive Keck telescope at the W. M. Keck Observatory on Maunakea in Hawaii.
The observatory’s Low Resolution Imaging Spectrometer recorded visible light from the shredded companion star, which glowed due to its high heat.
The companion star is now about the size of a large gaseous planet, or 20 times the mass of Jupiter. The side of the companion star that faces the neutron star is heated to 10,700 degrees Fahrenheit (5,927 degrees Celsius) — hot and bright enough to be seen by a telescope.
Neutron star cores are the densest matter in the universe, outside of black holes, and 1 cubic inch (16.4 cubic centimeters) of a neutron star weighs more than 10 billion tons, according to study author Roger W. Romani, a professor of physics at Stanford University in California.
This particular neutron star is the densest object within sight of Earth, according to the researchers.
“We know roughly how matter behaves at nuclear densities, like in the nucleus of a uranium atom,” said study coauthor Alex Filippenko in a statement. Filippenko holds dual titles of professor of astronomy and distinguished professor of physical sciences at the University of California, Berkeley.
“A neutron star is like one giant nucleus, but when you have one-and-a-half solar masses of this stuff, which is about 500,000 Earth masses of nuclei all clinging together, it’s not at all clear how they will behave.”
A neutron star like PSR J0952-0607 is called a pulsar because as it spins, the object acts like a cosmic lighthouse, regularly beaming out light through radio waves, X-rays or gamma rays.
Normal pulsars spin and flash about once a second, but this one is pulsing hundreds of times per second. This is because the neutron star becomes more energized as it strips material away from the companion star.
“In a case of cosmic ingratitude, the black widow pulsar, which has devoured a large part of its mate, now heats and evaporates the companion down to planetary masses and perhaps complete annihilation,” Filippenko said.
Astronomers first discovered the neutron star in 2017, and Filippenko and Romani have studied similar black widow systems for more than a decade. They have been trying to understand how large neutron stars can become. If neutron stars become too heavy, they collapse and become black holes.
The PSR J0952-0607 star is 2.35 times the mass of the sun, which is now considered to be the upper limit for a neutron star, the researchers said.
“We can keep looking for black widows and similar neutron stars that skate even closer to the black hole brink. But if we don’t find any, it tightens the argument that 2.3 solar masses is the true limit, beyond which they become black holes,” Filippenko said.
The heaviest neutron star known is shredding its companion
The heaviest neutron star ever detected is shredding its companion while spinning on its axis over 700 times per second.
The neutron star, known as PSR J0952-0607, was discovered in 2017 about 3,000 light-years from Earth in the constellation Sextans. Recent measurements show the star weighs 2.35 times as much as the sun, which makes it the heaviest neutron star known.
Neutron stars are stellar corpses, remnants of supernova explosions left behind when giant stars die after they run out of fuel in their cores. These stars, while only a few miles wide, boast the mass of the entire sun and more, making them the densest known objects in the universe apart from black holes.
Neutron stars are born spinning and can be detected only through beams of radio waves, X-rays and gamma rays, which they emit like cosmic light houses. Because of their blinking or pulsing nature, they are frequently referred to as pulsars.
Related: The first telescope of its kind will hunt for sources of gravitational waves
Most pulsars spin rather slowly, about once per second. PSR J0952-0607, on the other hand, completes over 700 rotations every second, which makes it one of the fastest spinning neutron stars known (in addition to being the heaviest). Thanks to its unique nature, PSR J0952-0607 can help scientists answer some profound questions about the nature of these puzzling objects.
Scientists, for example, think that when neutron stars get too heavy, they collapse onto themselves and turn into black holes. But they don’t know at what mass this collapsing process takes place. They also don’t understand the state of the matter inside of these stars, which are so dense that atoms likely cannot exist in their regular form inside them and instead get squashed into a soup of free-floating quarks (the constituents of protons and neutrons). The density of neutron stars is so high that one cubic inch (16 cubic centimeters) weighs over 10 billion tons.
“We know roughly how matter behaves at nuclear densities, like in the nucleus of a uranium atom” Alex Filippenko, Distinguished Professor of Astronomy at the University of California, Berkeley and one of the authors of a study describing the star, said in a statement. “A neutron star is like one giant nucleus, but when you have one-and-a-half solar masses of this stuff, which is about 500,000 Earth masses of nuclei all clinging together, it’s not at all clear how they will behave.”
PSR J0952-0607 is part of a binary system known as a black widow pulsar. Named after the notorious black widow spiders, which consume their partners after mating, these systems consist of a neutron star that devours matter from a companion star. This infalling matter is responsible for the mind-boggling rotation speed of these pulsars.
The neutron stars at the heart of the black widow pulsars are quite difficult to study by themselves as they are extremely faint.
The astronomers were able to estimate the mass of PSR J0952-0607 by focusing on the remnants of the companion star, which has by now been reduced to the size of a large planet, about 20 times the size of Jupiter. Using the 3.2-feet (10 meters) W. M. Keck Observatory on Maunakea in Hawai’i, they were able to obtain spectra of the visible light emitted by the disappearing companion. By comparing the spectra to that of similar stars, they were able to measure the orbital velocity of the companion star and calculate the mass of the neutron star.
Filippenko and his colleague Roger W. Romani, a professor of astrophysics at Stanford University, have studied about a dozen black widow binary systems in recent years, but only six of them had a companion star bright enough to enable them to calculate the neutron star’s mass.
“By combining this measurement with those of several other black widows, we show that neutron stars must reach at least this mass, 2.35 plus or minus 0.17 solar masses [before collapsing into black holes],” Romani said in the statement. “In turn, this provides some of the strongest constraints on the property of matter at several times the density seen in atomic nuclei. Indeed, many otherwise popular models of dense-matter physics are excluded by this result.”
The study was accepted for publication in the journal Astrophysical Journal Letters and is currently available online through the repository Arxiv.
Follow Tereza Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook.
Hubble Reveals Surviving Companion Star in Aftermath of Titanic Supernova Explosion
This artist’s illustration shows supernova 2013ge, with its companion star at the lower right. The companion star is impacted by the blast wave from the supernova, but not destroyed. Over time astronomers observed the ultraviolet (UV) light of the supernova fading, revealing a nearby second source of UV light that maintained brightness. The theory is that the two massive stars evolved together as a binary pair, and that the current survivor siphoned off its partner’s outer hydrogen gas shell before it exploded. Eventually, the companion star will also go supernova. Credit: NASA, ESA, Leah Hustak (STScI)
The discovery helps explain the puzzle of hydrogen loss pre-supernova, and supports the theory that most massive stars are paired.
It’s not unheard of to find a surviving star at the scene of a massive supernova explosion, which would be expected to obliterate everything around it, but the latest research from the
Suspicions that companion stars are to blame—siphoning away their partners’ outer shells before their death—are supported by Hubble’s identification of a surviving companion star on the scene of supernova 2013ge. The discovery also lends credence to the theory that most massive stars form and evolve as binary systems. It could also be the prequel to another cosmic drama: In time, the surviving, massive companion star will also undergo a supernova, and if both the stars’ remnant cores are not flung from the system, they will eventually merge and produce gravitational waves, shaking the fabric of space itself.
This infographic shows the evolution astronomers propose for supernova (SN) 2013ge. Panels 1-3 show what has already occurred, and panels 4-6 show what may take place in the future. 1) A binary pair of massive stars orbit one another. 2) One star ages into its red giant stage, getting a puffy outer envelope of hydrogen that its companion star siphons off with gravity. Astronomers propose this is why Hubble found no trace of hydrogen in the supernova debris. 3) The stripped-envelope star goes supernova (SN 2013ge), jostling but not destroying its companion star. After the supernova, the dense core of the former massive star remains either as a neutron star or a black hole. 4) Eventually the companion star also ages into a red giant, maintaining its outer envelope, some of which came from its companion. 5) The companion star also undergoes a supernova. 6) If the stars were close enough to each other not to be flung from their orbits by the supernova blast wave, the remnant cores will continue to orbit one another and eventually merge, creating gravitational waves in the process. Credit: NASA, ESA, Leah Hustak (STScI)
The finding provides crucial insight into the binary nature of massive stars, as well as the potential prequel to the ultimate merger of the companion stars that would rattle across the universe as 
Hubble images of galaxy NGC 3287 show supernova 2013ge fading over time, revealing the steady source of ultraviolet light astronomers have identified as its binary companion star. Credit: Science: NASA, ESA, Ori Fox (STScI), Image Processing: Joseph DePasquale (STScI)
The cause of the hydrogen loss had been a mystery, and astronomers have been using Hubble to search for clues and test theories to explain these stripped supernovae. The new Hubble observations provide the best evidence yet to support the theory that an unseen companion star siphons off the gas envelope from its partner star before it explodes.
“This was the moment we had been waiting for, finally seeing the evidence for a binary system progenitor of a fully stripped supernova,” said astronomer Ori Fox of the Space Telescope Science Institute in Baltimore, Maryland, lead investigator on the Hubble research program. “The goal is to move this area of study from theory to working with data and seeing what these systems really look like.”
Fox’s team used Hubble’s Wide Field Camera 3 to study the region of supernova (SN) 2013ge in ultraviolet light, as well as previous Hubble observations in the Barbara A. Mikulski Archive for Space Telescopes (MAST). Astronomers saw the light of the supernova fading over time from 2016 to 2020—but another nearby source of ultraviolet light at the same position maintained its brightness. This underlying source of ultraviolet emission is what the team proposes is the surviving binary companion to SN 2013ge.
Two by two?
Previously, scientists theorized that a massive progenitor star’s strong winds could blow away its hydrogen gas envelope, but observational evidence didn’t support that. To explain the disconnect, astronomers developed theories and models in which a binary companion siphons off the hydrogen.
“In recent years many different lines of evidence have told us that stripped supernovae are likely formed in binaries, but we had yet to actually see the companion. So much of studying cosmic explosions is like forensic science—searching for clues and seeing what theories match. Thanks to Hubble, we are able to see this directly,” said Maria Drout of the University of Toronto, a member of the Hubble research team.
Hubble image of galaxy NGC 3287. Credit: Science: NASA, ESA, Ori Fox (STScI), Image Processing: Joseph DePasquale (STScI)
In prior observations of SN 2013ge, Hubble saw two peaks in the ultraviolet light, rather than just the one typically seen in most supernovae. Fox said that one explanation for this double brightening was that the second peak shows when the supernova’s shock wave hit a companion star, a possibility that now seems much more likely. Hubble’s latest observations indicate that while the companion star was significantly jostled, including the hydrogen gas it had siphoned off its partner, it was not destroyed. Fox likens the effect to a jiggling bowl of jelly, which will eventually settle back to its original form.
While additional confirmation and similar supporting discoveries need to be found, Fox said that the implications of the discovery are still substantial, lending support to theories that the majority of massive stars form and evolve as binary systems.
One to Watch
Unlike supernovae that have a puffy shell of gas to light up, the progenitors of fully stripped-envelope supernovae have proven difficult to identify in pre-explosion images. Now that astronomers have been lucky enough to identify the surviving companion star, they can use it to work backward and determine characteristics of the star that exploded, as well as the unprecedented opportunity to watch the aftermath unfold with the survivor.
As a massive star itself, SN 2013ge’s companion is also destined to undergo a supernova. Its former partner is now likely a compact object, such as a
“With the surviving companion of SN 2013ge, we could potentially be seeing the prequel to a gravitational wave event, although such an event would still be about a billion years in the future,” Fox said.
This illustration demonstrates how a massive star (at least 8 times bigger than our sun) fuses heavier and heavier elements until exploding as a supernova and spreading those elements throughout space. Credit: NASA, ESA, and L. Hustak (STScI)
Fox and his collaborators will be working with Hubble to build up a larger sample of surviving companion stars to other supernovae, in effect giving SN 2013ge some company again.
“There is great potential beyond just understanding the supernova itself. Since we now know most massive stars in the universe form in binary pairs, observations of surviving companion stars are necessary to help understand the details behind binary formation, material-swapping, and co-evolutionary development. It’s an exciting time to be studying the stars,” Fox said.
“Understanding the lifecycle of massive stars is particularly important to us because all heavy elements are forged in their cores and through their supernovae. Those elements make up much of the observable universe, including life as we know it,” added co-author Alex Filippenko of the University of California at Berkeley.
The results are published in The Astrophysical Journal Letters.
Reference: “The Candidate Progenitor Companion Star of the Type Ib/c SN 2013ge” by Ori D. Fox, Schuyler D. Van Dyk, Benjamin F. Williams, Maria Drout, Emmanouil Zapartas, Nathan Smith, Dan Milisavljevic, Jennifer E. Andrews, K. Azalee Bostroem, Alexei V. Filippenko, Sebastian Gomez, Patrick L. Kelly, S. E. de Mink, Justin Pierel, Armin Rest, Stuart Ryder, Niharika Sravan, Lou Strolger, Qinan Wang and Kathryn E. Weil, 13 April 2022, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/ac5890
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.
Listen to the X-ray echoes of a black hole as it devours a companion star
The sound of a binary black hole’s echoes, courtesy of MIT’s Erin Kara and Kyle Keane. Animation computed by Michal Dovciak.
Black holes feeding on companion stars can go through cycles where they emit high-energy outbursts. MIT astronomers are using X-ray echoes from those cycles to map out the environment around these exotic objects, similar to how bats map out their environment via echolocation. The astronomers hope to use this new data to learn more about the evolution of these kinds of black hole systems, and by extension, the formation of galaxies, according to a new paper published in the Astrophysical Journal.
“The role of black holes in galaxy evolution is an outstanding question in modern astrophysics,” said co-author Erin Kara of MIT. “These black hole binaries appear to be ‘mini’ supermassive black holes, and so by understanding the outbursts in these small, nearby systems, we can understand how similar outbursts in supermassive black holes affect the galaxies in which they reside.”
As we’ve reported previously, it’s a popular misconception that black holes behave like cosmic vacuum cleaners, ravenously sucking up any matter in their surroundings. In reality, only stuff that passes beyond the event horizon—including light—is swallowed up and can’t escape, although black holes are also messy eaters. That means that part of an object’s matter is ejected in a powerful jet.
If that object is a star—such as the companion star of a black hole binary system—the process of being shredded (or “spaghettified”) by the powerful gravitational forces of a black hole occurs outside the event horizon, and part of the star’s original mass is ejected violently outward. This process can form a rotating ring of matter (aka an accretion disk) around the black hole that emits powerful X-rays, visible light, and sometimes radio waves. Those jets are one way astronomers can indirectly infer the presence of a black hole.
The MIT team was particularly interested in systems where the companion star is about one solar mass and exhibits cyclical outbursts in the form of X-ray flashes. Per the authors, most scientists think that a hot plasma located close to the black hole, called the X-ray corona, plays a role in these cycles, but questions remain about how the X-ray corona is formed in the first place, as well as how it evolves throughout an outburst.
Enlarge / Illustration of a black hole pulling material off a neighboring star and into an accretion disk.
Aurore Simonnet/NASA Goddard Space Flight Center
The emitted X-rays can sometimes reflect off the accretion disk, creating ‘echoes’ of the initial emission. And detecting those echoes offers an excellent opportunity for tracing how the black hole evolves as it feeds. Specifically, it’s possible to estimate the time lag between when a telescope detects light from the corona and when it picks up the X-ray echoes and monitor how that lag shifts as the system works through an outburst cycle.
Astronomers had previously detected X-ray echoes (or reverberations) from two binary systems in the Milky Way galaxy. To hunt for more, the MIT team developed an automated search tool dubbed the “Reverberation Machine” and used it to analyze data collected by NASA’s Neutron star Interior Composition Explorer (NICER) on board the ISS. The Reverberation Machine identified 26 candidate black hole binary systems, and of those, 10 (including the previously detected systems) were emitting detectable X-ray echoes.
All of the eight new black hole binary systems emitting echoes ranged from five to 15 solar masses, and all the companion stars were about the size of our Sun. “As far as we can tell, the fact that we only see detections in about half of the black holes is due to their higher quality of data, not because they are particularly unique,” Kara told Ars.
What does this new data tell astronomers about how a binary black hole evolves during an outburst? The MIT team was able to construct a reasonably universal picture. The system typically begins in a relatively quiescent state. As material falls onto the accretion disk faster, the X-ray emission also increases in luminosity, dominated by “hard” X-rays. This so-called “hard state” produces the corona and a jet of particles emitted into space at close to the speed of light. During this period, the team found that the time lags between emission and echo were short and fast, lasting mere milliseconds.
After several weeks, the outburst cycle has run its course—because the black hole has nearly finished its stellar meal—producing one last dramatic flash before it enters a “soft” lower-energy state, eventually returning to quiescence. The MIT team was intrigued to find that, during this transition, the time lags became longer for all 10 of the systems, implying an increase in the distance between the corona and the accretion disk. They suggested that this could result from the corona expanding during the final high energy burst.
“We’re at the beginnings of being able to use these light echoes to reconstruct the environments closest to the black hole,” said Kara. “Now we’ve shown these echoes are commonly observed, and we’re able to probe connections between a black hole’s disk, jet, and corona in a new way.”