Massive stars about eight times more massive than the Sun explode as supernovae at the end of their lives. The explosions, which leave behind a black hole or a neutron star, are so energetic they can outshine their host galaxies for months. However, astronomers appear to have spotted a massive star that skipped the explosion and turned directly into a black hole. Stars are balancing acts between the outward force of fusion and the inward force of their own gravity. When a massive star enters its last evolutionary stages, it begins to run out of hydrogen, and its fusion weakens. The outward force from its fusion can no longer counteract the star’s powerful gravity, and the star collapses in on itself. The result is a supernova explosion, a calamitous event that destroys the star and leaves behind a black hole or a neutron star. However, it appears that sometimes these stars fail to explode as supernovae and instead turn directly into black holes. New research shows how one massive, hydrogen-depleted supergiant star in the Andromeda galaxy (M31) failed to detonate as a supernova. The research is “The disappearance of a massive star marking the birth of a black hole in M31.” The lead author is Kishalay De, a postdoctoral scholar at the Kavli Institute for Astrophysics and Space Research at MIT. These types of supernovae are called core-collapse supernovae, also known as Type II. They’re relatively rare, with one occurring about every one hundred years in the Milky Way. Scientists are interested in supernovae because they are responsible for creating many of the heavy elements, and their shock waves can trigger star formation. They also create cosmic rays that can reach Earth. This new research shows that we may not understand supernovae as well as we thought. Artist’s impression of a Type II supernova explosion. These supernovae explode when a massive star nears the end of its life and leaves behind either a black hole or a neutron star. But sometimes, the supernova fails to explode and collapses directly into a black hole. Image Credit: ESO The star in question is named M31-2014-DS1. Astronomers noticed it brightening in mid-infrared (MIR) in 2014. For one thousand days, its luminosity was constant. Then, for another thousand days between 2016 and 2019, it faded dramatically. It’s a variable star, but that can’t explain these fluctuations. In 2023, it was undetected in deep optical and near-IR (NIR) imaging observations. The researchers say that the star was born with an initial mass of about 20 stellar masses and reached its terminal nuclear-burning phase with about 6.7 stellar masses. Their observations suggest that the star is surrounded by a recently ejected dust shell, in accordance with a supernova explosion, but there’s no evidence of an optical outburst. “The dramatic and sustained fading of M31-2014-DS1 is exceptional in the landscape of variability in massive, evolved stars,” the authors write. “The sudden decline of luminosity in M31-2014-DS1 points to the cessation of nuclear burning together with a subsequent shock that fails to overcome the infalling material.” A supernova explosion is so powerful that it completely overcomes infalling material. “Lacking any evidence for a luminous outburst at such proximity, the observations of M31-2014-DS1 bespeak signatures of a ‘failed’ SN that leads to the collapse of the stellar core,” the authors explain. What could make a star fail to explode as a supernova, even if it’s the right mass to explode? Supernovae are complex events. The density inside a collapsing core is so extreme that electrons are forced to combine with protons, creating both neutrons and neutrinos. This process is called neutronization, and it creates a powerful burst of neutrinos that carries about 10% of the star’s rest mass energy. The outburst is called a neutrino shock. Neutrinos get their name from the fact that they’re electrically neutral and seldom interact with regular matter. Every second, about 400 billion neutrinos from our Sun pass right through every person on Earth. But in a dense stellar core, the neutrino density is so extreme that some of them deposit their energy into the surrounding stellar material. This heats the material, which generates a shock wave. The neutrino shock always stalls, but sometimes it revives. When it revives, it drives an explosion and expels the outer layer of the supernova. If it’s not revived, the shock wave fails, and the star collapses and forms a black hole. This image illustrates how the neutrino shock wave can stall, leading to a black hole without a supernova explosion. A shows the initial shock wave with cyan lines representing neutrinos being emitted and the red circle representing the shock wave propagating outward. B shows the neutrino shock stalling, with white arrows representing infalling matter. The outer layers fall inward, and the neutrino heating isn’t powerful enough to revive the shock. C shows the failed shock dissipating as a dotted red line and the stronger white arrows represent the collapse accelerating. The outer layers are falling in rapidly, and the core is becoming more compact. D shows the black hole forming, with the blue circle representing the event horizon and the remaining material forming an accretion disk. (Credit: Original illustration created for this article.) In M31-2014-DS1, the neutrino shock was not revived. The researchers were able to constrain the amount of material ejected by the star, and it was far below what a supernovae would eject. “These constraints imply that the majority of stellar material (?5 solar masses) collapsed into the core, exceeding the maximum mass of a neutron star (NS) and forming a BH,” they conclude. About 98% of the star’s mass collapsed and created a black hole with about 6.5 solar masses. M31-2014-DS1 isn’t the only failed supernova, or candidate failed supernova, that astronomers have found. They’re difficult to spot because they’re characterized by what doesn’t happen rather than what does. A supernova is hard to miss because it’s so bright and appears in the sky suddenly. Ancient astronomers recorded several of them. In 2009, astronomers discovered the only other confirmed failed supernova. It was a supergiant red star in NGC 6946, the “Fireworks Galaxy.” It’s named N6946-BH1 and has about 25 solar masses. After disappearing from view, it left only a faint infrared glow. In 2009, its luminosity increased to a million solar luminosities, but by 2015, it had disappeared in optical light. A survey with the Large Binocular Telescope monitored 27 nearby galaxies, looking for disappearing massive stars. The results suggest that between 20% and 30% of massive stars can end their lives as failed supernovae. However, M31-2014-DS1 and N6946-BH1 are the only confirmed observations. The post A Star Disappeared in Andromeda, Replaced by a Black Hole appeared first on Universe Today.

The impacts could be chronic.

You might be surprised by his post-election message. Continue reading…

Michael Jordan’s NASCAR Team Sideswiped By Federal Judge [WATCH]

Before diving into Christmas content, don't forget to add these fun Thanksgiving movies to your watchlist.

Formed in Canada back in 1968, Rush became one of the most influential and successful power trios of all time. The bassist, singer and keyboardist Geddy Lee was certainly a fundamental part of the group and was an inspiration for countless musicians who appeared later on. A really nice guy, who often talks to the press, Geddy talked over the decades about many other bands. He even once mentioned the Canadian group, which in his opinion is one of the greatest of all time. The Canadian band Geddy Lee said is one of the best of all time It was in an interview with CBC Music back in 2016 (Transcribed by Rock and Roll Garage), one year before Gord Downie’s death and the end of the band, that Geddy Lee said the Tragically Hip was the ultimate Canadian band. The group was formed in Kingston, Ontario, Canada in 1984 and was active until 2017. “Calling The Hip a Canadian band or the ultimate Canadian band, however you wanna look at it, is an interesting question, because what is it that makes them uniquely Canadian? I don’t know that. I consider them uniquely Canadian, but they are certainly one of the greatest bands that we’ve ever produced in this country. Their popularity goes coast to coast and is undeniable.” “Their catalog is deep, their sound is sort of born, to me, out of folk and blues, amplified. The voice of Gord Downie and his poetry have given it a very, very unique tone. I’ve always found it very affecting. I guess the fact that a lot of their subject matter deals with locations in this country." Geddy Lee continued: "Particularly in my home province of Ontario makes them uniquely Ontarian. But they’re just a great band. Simply, just a great band. Whether they’re Canadian, whether they’re from anywhere, they would still be just as great,” Geddy Lee said. The Tragically Hip were Rush's opening act back in 1991 during the tour the power trio was promoting their album "Roll The Bones". Geddy said he was really impressed with the energy and the way the lyrics of their songs fit with the music. During their career, The Tragically Hip released 13 studio albums. Some of their most famous songs are “Bobcaygeon”, “New Orleans Is Sinking”, “Wheat Kings and “Ahead By A Century”. They received multiple Canadian music awards from 1996 to 2016. They were also the best-selling band in Canada and the fourth best-selling Canadian artist overall in Canada. Geddy Lee’s favorite Tragically Hip song [embed]https://www.youtube.com/watch?v=X0zWpWALWEI&pp=ygURZmlmdHkgbWlzc2lvbiBjYXA%3D[/embed] During the same interview with CBC (Transcribed by Rock and Roll Garage), the legendary Rush frontman revealed that "Fifty-Mission Cap" is his favorite song by them. He also noted that it must be the most "Canadian" song of the band. It was first featured on their 1993 album "Fully Completely". “You know, I love ‘Fifty-Mission Cap’, to me is probably that’s probably the most Canadian Hip song there is (Laughs). You could make an argument for ‘Bobcaygeon’. But there is something about the mystery of Bill Barilko put into lyrics.” “It just seems like such a strange and uniquely Canadian take on that whole thing. Especially Gord has a great way of personalizing whatever he’s talking about. You know, I look at this lyric writing as short story writing and he really puts you in a place, in a character’s mindset. There’s sort of nostalgia, mystery and Rock and Roll all mixed together in Fifty-Mission Cap,” Geddy Lee said. During their 33-year career, the band reached number 1 on the Canadian charts 9 times. He also praised "Ahead By a Century" [embed]https://www.youtube.com/watch?v=QE2joQsWXJg&pp=ygUSYWhlYWQgYnkgYSBjZW50dXJ5[/embed] Lee also praised in the conversation the track "Ahead by a Century". The track was first featured on their 1996 album "Trouble at the Henhouse". "I just think that 'Ahead By a Century" is a beautifully written song. I'm not even sure what it's about. But I get the feeling that I know what it's about. That's the hallmark of good poetry. You can read poetry of any kind and you get a feeling of what the poet is talking about." "You'll never know exactly what was in that poet's mind and I think that holds true with Gord's writing. You're never a hundred percent sure that you've nailed what he's talking about. But you have a feeling you do and that feeling becomes close to you. That's a great poet to me," Geddy Lee said.The post The Canadian band Geddy Lee said is one of the best of all time appeared first on Rock And Roll Garage.

Arizona officials have estimated that general election results could take about two weeks to finalize this year, which is consistent with past elections. AllSides highlights content from Gigafact, a network of newsrooms that respond to online claims. View the full fact brief on ACIR.

Although Colorado joined the National Popular Vote Compact, the pact has not taken effect because not enough states have signed on to make it legally binding. AllSides highlights content from Gigafact, a network of newsrooms that respond to online claims. View the full fact brief on Colorado Sun.

Whoa, baby! Fielding questions about where babies come from can be a full-time job, especially when you’ve got a classroom full of curious kids. Most times, this big question is left to the parents, who sometimes give elaborate answers that they invariably need to correct when the child is older. I’ve heard parents tell kids that babies come from watermelon seeds that get accidentally swallowed or that a stork drops babies off on doorsteps (I’ve yet to hear where the stork gets this unsuspecting child). People can spin some tall tales in an effort to avoid answering the question of where babies come from and how they get out. In 2022, A K-5 science teacher in North Carolina decided she was going to answer questions from her curious second grade class with age-appropriate truthful answers. Nancy Bullard was preparing for maternity leave with her first child and realized she would need to inform her class that she would be out for a few months so they wouldn’t be concerned.Bullard told Today Parents, "I didn’t want them to get caught off guard when I stopped coming to school. Plus, I wanted to reassure them that my leave was temporary." Bullard has a rotating group of students that come through her science lab weekly and she decided to turn her expected absence into a lesson she titled “Baby Bonanza.” During the lesson, the kids were able to draw the baby and guess his birthday, weight and time of birth.Bullard also said the students gave her very cute parenting advice and tips on how to be a good mom. Some of this included singing the baby a song to throwing a piece of cheese on its face. The cheese was inspired by a TikTok video, the child admitted, but other gems included feeding and changing the baby, while one child suggested running away if the baby started crying. When Mrs. B. returned to work after welcoming her first child, Sam, a baby boy, the kids were ready to learn more, and Mrs. B did not disappoint. Bullard told Today Parents, "I wanted to take a few minutes to catch up with students, introduce them to my son, and let them ask questions. When I wrote my lesson plan for this day I planned to spend about five minutes answering questions, but ended up spending nearly 20 minutes doing so." Login • Instagram See on Instagram The students were filled with curiosity when their teacher returned. One asked “Is it difficult to have a baby?” to which Mrs. B. responded, “Yeah, yeah it is. It’s pretty tough.” Another student asked if the baby slept with his mom and dad, while another wanted to know the big question. You know: Where do babies come from? Without missing a beat, Bullard answered like the science teacher she is, with “They come from an organ called your uterus,” while pointing to her lower belly.Bullard explained to Today that she taught a lesson earlier in the year about organs and organ function to her kids in K-5. “Regardless of age, all my students understand the basic concept of pregnancy: There was a baby inside me, now that baby is out, and I spent maternity leave taking care of him … Students were interested, curious, and excited to get their questions answered," the new mom said. "As a science teacher, I welcome curiosity and always strive to answer questions factually."The elementary science teacher shared the video on TikTok and Instagram, “Mrs. B TV,” where the video has racked up more than 7 million views across the two platforms. May all children be so lucky as to have a Mrs. B. at some point in their school career.This article originally appeared on 4.5.22