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Three supermassive black holes found lurking in one galaxy NGC 6240 is a well-studied example of a galaxy merger. But the discovery that it hides three supermassive black holes makes it a stunning example of a galaxy formed through a triple merger. By Alison Klesman  |  Published: Friday, November 22, 2019 RELATED TOPICS: BLACK HOLES | GALAXIES The strange galaxy NGC 6240 is an ultra-rare example of a galaxy harboring three supermassive black holes near its core. Astronomers already knew of the galaxy's active, northern black hole (N), but thanks to cutting-edge 3D-mapping techniques, they've now identified two more —...

WASHINGTON (AFP) – A massive bright reddish star in the Orion constellation has mysteriously shrunk by over 15 percent in the last 15 years and astronomers have not yet determined why, according to a study released Tuesday. Betelgeuse, considered a supergiant star, is so large that it would reach to Jupiter's orbit in our solar system. But at a radius of about five astronomical units, the star has shrunk in size since 1993 by a distance equivalent to Venus's orbit. "To see this change is very striking," University of California, Berkley professor Charles Townes, who whon the 1964 Nobel Prize...

Intense pressure can force neutrons into cubes rather than spheres, say physicistsInside atomic nuclei, protons and neutrons fill space with a packing density of 0.74, meaning that only 26 percent of the volume of the nucleus in is empty. That's pretty efficient packing. Neutrons achieve a similar density inside neutron stars, where the force holding neutrons together is the only thing that prevents gravity from crushing the star into a black hole. Today, Felipe Llanes-Estrada at the Technical University of Munich in Germany and Gaspar Moreno Navarro at Complutense University in Madrid, Spain, say neutrons can do even better. These...

The quasar OJ287 contains two black holes (this slightly dated illustration lists the larger black hole's mass as 17 billion Suns, though researchers now estimate it is 18 billion Suns). The smaller black hole crashes through a disc of material around the larger one twice every orbit, creating bright outbursts (Illustration: VISPA) The most massive known black hole in the universe has been discovered, weighing in with the mass of 18 billion Suns. Observing the orbit of a smaller black hole around this monster has allowed astronomers to test Einstein's theory of general relativity with stronger gravitational fields than ever...

[T]he study of GRBs have been complicated by two major issues. On the one hand, GRBs are very short lived, lasting for only seconds at a time. Second, all detected events have occurred in distant galaxies, some of which were billions of light-years away. Nevertheless, there are a few theories as to what could account for them, ranging from the formation of black holes and collisions between neutron stars to extra-terrestrial communications. ... With the assistance of their collaborators in the US, France, the UK and Sweden, the team from Queen’s University Belfast relied on the Gemini laser, located at...

Phil PlaitNovember 16, 2015 A new study says that violent space weather that could cost $2 trillion in damage is more common than previously thought In the years 774 and 993, the Earth was attacked from space. Not by aliens, but by a natural event—and it was very, very powerful. Whatever it was, it subtly altered the chemistry of our planet’s atmosphere, creating trace amounts of radioactive elements like chlorine-36, beryllium-10, and carbon-14. And those provide the clue to what the event was: Those isotopes are created when high-energy protons slam into our air. That means the source must have...

Thanks to a lucky break and an overactive galaxy, astronomers have for the first time caught a massive star in the act of exploding. An X-ray outburst recently recorded by NASA's Swift satellite suggests that researchers began viewing the violent demise of a star in the galaxy NGC 2770 just a few seconds after the first X rays arrived at Earth, and hours before the first visible-light fireworks. Most supernovas aren't identified until they generate an outpouring of visible light, long after key information about the size and other properties of the collapsing star has vanished. The new finding suggests...

Imagine what our night sky would look like if its stellar density was a million times greater than it is now. Remarkably, such places actually exist: They’re called “Ultracompact Dwarfs,” and astronomers are calling them an entirely new kind of galaxy. Undergraduate astronomy students Michael Sandoval and Richard Vo from San José University discovered a pair of record-breaking compact galaxies buried within data contained in the Sloan Digital Sky Survey. These exotic objects are similar to ordinary globular clusters, but upwards of a hundred to a thousand times brighter. Advertisement Image: The two ultra-dense compact galaxies were discovered orbiting...

Explanation: The Great Nebula in Orion is an intriguing place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. But this image, an illusory-color four-panel mosaic taken in different bands of infrared light with the Earth orbiting WISE observatory, shows the Orion Nebula to be a bustling neighborhood or recently formed stars, hot gas, and dark dust. The power behind much of the Orion Nebula (M42) is the stars of the Trapezium star cluster, seen near the center of the above wide field image. The orange glow surrounding the bright stars pictured...

WASHINGTON (AFP) – The US space agency's Fermi telescope has detected a massive explosion in space which scientists say is the biggest gamma-ray burst ever detected, a report published Thursday in Science Express said. The spectacular blast, which occurred in September in the Carina constellation, produced energies ranging from 3,000 to more than five billion times that of visible light, astrophysicists said. "Visible light has an energy range of between two and three electron volts and these were in the millions to billions of electron volts," astrophysicist Frank Reddy of US space agency NASA told AFP. "If you think about...

An exploded star some 3.8 billion light-years away is forcing scientists to overhaul much of what they thought they knew about gamma-ray bursts – intense blasts of radiation triggered, in this case, by a star tens of times more massive than the sun that exhausted its nuclear fuel, exploded, then collapsed to form a black hole. Last April, gamma rays from the blast struck detectors in gamma-ray observatories orbiting Earth, triggering a frenzy of space- and ground-based observations. Many of them fly in the face of explanations researchers have developed during the past 30 years for the processes driving the...

For a fraction of a second in December, a dying remnant of an exploded star let out a burst of light that outshone the Milky Way's other half-trillion stars combined, astronomers announced today. Even on Earth, half a galaxy away, the starburst was one of the brightest objects ever observed in the sky, after the Sun and perhaps a few comets. The magnitude of the event caught most astronomers by surprise. "Whoppingly bright," said Dr. Brian Gaensler, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "It gave off more energy in 0.2 seconds than the Sun does...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2004 June 4 Sedna at Noon Illustration Credit: Adolf Schaller, ESA, NASA Explanation: Standing on Sedna - the solar system's most distant known planetoid - your view of the Sun at high noon might look something like this. An artist's dramatic vision, the picture shows the Sun suspended above the nearby horizon as a bright star immersed in the dusty ecliptic plane. Within the dust-scattered sunlight are more...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 April 14 A Gamma Ray Burst - Supernova Connection Credit: Al Kelly (JSCAS/NASA) & Arne Henden (Flagstaff/USNO) Explanation: New evidence has emerged that a mysterious type of explosion known as a gamma ray burst is indeed connected to a supernova of the type visible in the above image. Two weeks ago, the orbiting HETE satellite detected gamma-ray burst GRB030329. The extremely bright burst was found hours later...

When the Fermi team did the calculations, using the most conservative estimates for how astrophysics plays into this, they determined that the mass scale must be at least 1.2 times the Planck mass, and by using reasonable but less conservative assumptions, they derived lower limits on the mass scale of up to 100 times the Planck mass. One way to interpret this is to say that there is no variation of the speed of light coming from any quantum gravity effects at less than 1.2 times the Planck mass. And given that some quantum gravity frameworks predict that effects should...

Enough gold, uranium and other heavy elements about equal in mass to all of Earth's oceans likely came to the solar system from the collision of two neutron stars billions of years ago, a new study finds. If the same event were to happen today, the light from the explosion would outshine the entire night sky, and potentially prove disastrous for life on Earth, according to the new study's researchers. Recent findings have suggested that much of the gold and other elements heavier than iron on the periodic table was born in the catastrophic aftermath of colliding neutron stars,...

Radio observations using a combination of NSF’s Very Long Baseline Array, the Karl G. Jansky Very Large Array and the Robert C. Byrd Green Bank Telescope have revealed that a fast-moving jet of particles broke out into interstellar space after a pair of neutron stars merged in NGC 4993, a lenticular galaxy approximately 130 million light-years from Earth.-snip- Called GW170817, the merger of two neutron stars sent gravitational waves rippling through space. It was the first event ever to be detected both by gravitational waves and electromagnetic waves, including gamma rays, X-rays, visible light, and radio waves.The aftermath of the...

Earth could be in for a neighborhood dispute with a death star, according to an Australian astronomer. A spectacular rotating pinwheel system just down the astronomical road from Earth — 8,000 light years away — includes an unstable Wolf-Rayet star that could explode. Eight years ago, WR104 was discovered in the constellation Sagittarius by Sydney University astronomer Peter Tuthill. A Wolf-Rayet star is the last step on the way to a supernova — the explosion of a star at the end of its life. Images from the Mauna Kea in Hawaii telescope show that every eight months the two stars...

A brief but extremely powerful cosmic blast from a distance galaxy has taken the record for the brightest light ever seen from Earth. It was emitted by a gamma ray burst seven billion light-years away and created more energy in a few seconds than the sun will burn in its 10 billion year lifetime. The discovery, led by researchers from Curtin University in Western Australia involved more than 300 scientists from around the world. Gamma-ray bursts are the most energetic events in the universe - the most massive since the Big Bang, says co author of the study, Dr Gemma...

An emerging consensus suggests the crash can explain distant gamma-ray bursts GREAT ESCAPE A bright jet of fast-moving particles fled the scene after two neutron stars collided, spewing material and potentially forming a black hole (shown in this artist’s illustration). When a pair of ultradense cores of dead stars smashed into one another, the collision shot a bright jet of charged subatomic particles through space. Astronomers thought no such jet had made it out of the wreckage of the neutron star crash, first detected in August 2017. But new observations of the crash site using a network of radio telescopes...