What is a galaxy?

We live in a galaxy called the Milky Way. But there is so much more to know about these grand and glorious star islands in space! Click in here, and prepare to have your mind expanded. Source: https://earthsky.org/astronomy-essentials/definition-what-is-a-galaxy…

The Only Black Hole We’ve Ever Seen Has a Shadow That Wobbles

The supermassive black hole at the center of the M87 galaxy has a shadow crescent that moves, like a dancer in the dark. From a report: Over a year ago, scientists unleashed something incredible on the world: the first photo of a black hole ever taken. By putting together radio astronomy observations made with dishes across four continents, the collaboration known…

Insight-HXMT discovers closest high-speed jet to black hole

Insight-HXMT, China’s first space X-ray astronomical satellite, has discovered a low-frequency quasi-periodic oscillation (QPO) above 200 kiloelectron volts (keV) in a black hole binary, making it the highest energy low-frequency QPO ever found. The scientists also found that the QPO originated from the precession of a relativistic jet (high-speed outward-moving plasma stream) near the event horizon of the black hole. These…

Researcher proposes universal mechanism for ejection of matter by black holes

Black holes can expel a thousand times more matter than they capture. The mechanism that governs both ejection and capture is the accretion disk, a vast mass of gas and dust spiraling around the black hole at extremely high speeds. The disk is hot and emits light as well as other forms of electromagnetic radiation. Part of the orbiting matter is…

New observations of black hole devouring a star reveal rapid disk formation

When a star passes too close to a supermassive black hole, tidal forces tear it apart, producing a bright flare of radiation as material from the star falls into the black hole. Astronomers study the light from these “tidal disruption events” (TDEs) for clues to the feeding behavior of the supermassive black holes lurking at the centers of galaxies. Source: https://phys.org/news/2020-08-black-hole-devouring-star-reveal.html…

Space telescope to study quasars and their host galaxies in three dimensions

Supermassive black holes, which likely reside at the centers of virtually all galaxies, are unimaginably dense, compact regions of space from which nothing—not even light—can escape. As such a black hole, weighing in at millions or billions of times the mass of the Sun, devours material, it is surrounded by a swirling disk of gas. When gas from this disk falls…

Strange gamma-ray heartbeat puzzles scientists

Scientists have detected a mysterious gamma-ray heartbeat coming from a cosmic gas cloud. The inconspicuous cloud in the constellation Aquila is beating with the rhythm of a neighboring precessing black hole, indicating a connection between the two objects, as the team led by DESY Humboldt Fellow Jian Li and ICREA Professor Diego F. Torres from the Institute of Space Sciences (IEEC-CSIC)…

Fastest star ever seen is moving at 8% the speed of light

In the center of our galaxy, hundreds of stars closely orbit a supermassive black hole. Most of these stars have large enough orbits that their motion is described by Newtonian gravity and Kepler’s laws of motion. But a few orbit so closely that their orbits can only be accurately described by Einstein’s theory of general relativity. The star with the smallest…

Runaway star might explain black hole’s disappearing act

At the center of a far-off galaxy, a black hole is slowly consuming a disk of gas that swirls around it like water circling a drain. As a steady trickle of gas is pulled into the gaping maw, ultrahot particles gather close to the black hole, above and below the disk, generating a brilliant X-ray glow that can be seen 300…

Scientists propose plan to determine if Planet Nine is a primordial black hole

Scientists at Harvard University and the Black Hole Initiative (BHI) have developed a new method to find black holes in the outer solar system, and along with it, determine once-and-for-all the true nature of the hypothesized Planet Nine. The paper, accepted to The Astrophysical Journal Letters, highlights the ability of the future Legacy Survey of Space and Time (LSST) mission to…