Space and astronomy news
In 1936 astronomers watched as FU Orionis, a dim star in the Orion constellation, brightened dramatically. The star’s brightness increased by a factor of 100 in a matter of months. When it peaked, it was 100 times more luminous than our Sun.
Astronomers had never observed a young star brightening like this.
Continue reading “The Hubble and FU Orionis: a New Look at an Old Mystery”
If you were lucky enough to observe a total eclipse, you are certain to remember the halo of brilliant light around the Moon during totality. It’s known as the corona, and it is the diffuse outer atmosphere of the Sun. Although it is so thin we’d consider it a vacuum on Earth, it has a temperature of millions of degrees, which is why it’s visible during a total eclipse. According to our understanding of black hole dynamics black holes should also have a corona. And like the Sun’s corona, it is usually difficult to observe. Now a study in The Astrophysical Journal has made observations of this elusive region.
Continue reading “Astronomers Map the Shape of a Black Hole's Corona for the First Time”
Black holes are by their very nature, challenging to observe and difficult to spot. It’s usually observations of the accretion disk that reveal properties of the hidden black hole. There is often enough material within the accretion disk to make them shine so brightly that they can often be among the brightest objects in space. A wonderful image has been released which shows the highest resolution simulation of a black hole accretion disk ever created.
Continue reading “Simulating the Accretion Disk Around a Black Hole”
Some Supermassive Black Holes (SMBHs) consume vast quantities of gas and dust, triggering brilliant light shows that can outshine an entire galaxy. But others are much more sedate, emitting faint but steady light from their home in the heart of their galaxy.
Observations from the now-retired Spitzer Space Telescope help show why that is.
Continue reading “Not All Black Holes are Ravenous Gluttons”
We can’t see them directly, but we know they’re there. Supermassive black holes (SMBHs) likely dwell at the center of every large galaxy. Their overwhelming gravity draws material toward them, where it collects in an accretion disk, waiting its turn to cross the event horizon into oblivion.
But in one galaxy, the SMBH has choked on its meal and spit it out, sending material away at high speeds and clearing out the entire neighbourhood.
Continue reading “A Black Hole Has Cleared Out Its Neighbourhood”
Pulsars are the lighthouses of the universe. These rotating dead stars shoot twin jets of radiation from their poles, usually with a predictable rhythm. But sometimes pulsars behave strangely, and one pulsar in particular has had astronomers scratching their heads for years. It’s called PSR J1023+0038, and a decade ago, it shut off its jets and began oscillating between two brightness levels in an unpredictable pattern. Now, scientists think they understand why: it is busy eating a neighboring star.
Continue reading “A Bizarre Pulsar Switches Between Two Brightness Modes. Astronomers Finally Figured Out Why.”
Black holes swallow everything—including light—which explains why we can’t see them. But we can observe their immediate surroundings and learn about them. And when they’re on a feeding binge, their surroundings become even more luminous and observable.
This increased luminosity allowed astronomers to find a black hole that was feasting on material only 800 million years after the Universe began.
Continue reading “Hungry Black Hole was Already Feasting 800 Million Years After the Big Bang”
Black holes are among the most awesome and mysterious objects in the known Universe. These gravitational behemoths form when massive stars undergo gravitational collapse at the end of their lifespans and shed their outer layers in a massive explosion (a supernova). Meanwhile, the stellar remnant becomes so dense that the curvature of spacetime becomes infinite in its vicinity and its gravity so intense that nothing (not even light) can escape its surface. This makes them impossible to observe using conventional optical telescopes that study objects in visible light.
As a result, astronomers typically search for black holes in non-visible wavelengths or by observing their effect on objects in their vicinity. After consulting the Gaia Data Release 3 (DR3), a team of astronomers led by the University of Alabama Huntsville (UAH) recently observed a black hole in our cosmic backyard. As they describe in their study, this monster black hole is roughly twelve times the mass of our Sun and located about 1,550 light-years from Earth. Because of its mass and relative proximity, this black hole presents opportunities for astrophysicists.
Continue reading “A Monster Black Hole has Been Found Right in our Backyard (Astronomically Speaking)”
Astronomers using the ALMA Observatory have discovered an unusual, massive star near the center of our galaxy, a star that has two spiral arms. The arms are part of an accretion disk, a broad disk of dust and gas surrounding the protostar. While this is not the first star to be seen with such rare arm-like features, researchers say they believe they can track the formation of the spiral arms to a close encounter the star had with another object.
Continue reading “A Star has Grown Spiral Arms”
Fifty years ago, English mathematical physicist and Nobel-prize winner Roger Penrose proposed that energy could be extracted from the space around a rotating black hole. Known as the ergosphere, this region lies just outside an event horizon, the boundary within which nothing can escape a black hole’s gravitational pull (even light). It is also here where infalling matter is accelerated to incredible speeds and emits all kinds of energy.
This became known as the Penrose Process, which many theorists have since expanded on. The latest comes from a study conducted by researchers from Columbia University and the Universidad Adolfo Ibáñez in Chile. With support from organizations like NASA, they demonstrated how a better understanding of the physics at work around spinning black holes could allow us to harness their energy someday.
Continue reading “A New Idea to Harness Energy From Black Holes”