accretion disks

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Cosmic ‘Spitballs’ Released From Milky Way’s Black Hole

“Black holes don’t just provide gravity, absorb incoming matter and prevent anything from escaping. They also gravitationally pull on and tear matter that passes nearby, including stars. In a surprising find, a new study out of Harvard shows that torn-apart stars aren’t merely reduced into gas, but they form dense streams that re-condense into planets in just year-long timescales. Moving rapidly away from the central black hole, these 'cosmic spitballs’ represent a brand new population of rogue planets, and are potentially the most catastrophic objects from space careening through our galaxy.”

Imagine you’re a star passing too close to a black hole. What’s going to happen to you? Yes, you’ll be tidally disrupted and eventually torn apart. Some of the matter will be swallowed, some will wind up in an accretion disk, and some will be accelerated and ejected entirely. But quite surprisingly, the ejected matter doesn’t just come out in the form of hot gas, but it condenses into large numbers of rapidly-moving planets. This population should make up approximately one out of every 1000 rogue planets, but should be uniquely identifiable. The vast majority will move at incredible speeds of around 10,000 km/s, be approximately the mass of Jupiter but will be made out of shredded star material, rather than traditional planetary material. As the next generation of infrared telescopes come online, these ‘cosmic spitballs’ should be one of the most exciting novel discoveries of all.

Come get the whole story on cosmic spitballs, fresh from the AAS meeting!

Quasar Banishing Spell 🌌💫

“A quasar is believed to be a supermassive black hole surrounded by an accretion disk. An accretion disk is a flat, disk-like structure of gas that rapidly spirals around a larger object, like a black hole, a new star, a white dwarf, etc. A quasar gradually attracts this gas and sometimes other stars or or even small galaxies with their gravity - these objects get sucked into the black hole. When a galaxy, star, or gas is absorbed into a quasar in such a way, the result is a massive collision of matter that causes a gigantic explosive output of radiation energy and light. This great burst of energy results in a flare, which is a distinct characteristic of quasars.”

When banishing objects, it’s never a bad idea to fill the leftover void with positive energy.

This spell is designed to banish negative energy into the supermassive black hole that is generally coupled with a quasar and invite positive energy using the brilliant light emitted from a quasar.

Ingredients:

  • Visualization
  • Stardust powder
  • Black Candle
  • White Candle
  • Onyx
  • Clear Quartz

Instructions:

  1. Sprinkle stardust powder around the wick of your candles and light them
  2. Hold the onyx in your left hand to represent the supermassive black hole, and hold the quartz in your right hand to represent the quasar 
  3. Close your eyes and visualize the energy you wish to banish being absorbed into the supermassive black hole (onyx)
  4. Then, visualize positive energy being emitted from the quasar (clear quartz)
  5. Open your eyes, and discard the onyx however you wish but store the clear quartz in a safe place
  6. Snuff out your candles 

🌌🌟🌠🔮

Centaurus A Extreme Deep Field

Centaurus A is the closest radio galaxy to us and is hosting an Active Galactic Nuleus (AGN) in its centre. It is believed that the twisting of magnetic fields in the accretion disk around the central supermassive black hole collimates the outflow along its rotation axis, so a resulting jet of plasma emerges from each face of the accretion disk.

Credit: Rolf Olsen

vimeo

This short clip of a rounded ring of ice spinning on the Middle Fork Snoqualmie River in Washington was one of the most popular videos shared on Social Media this week. Ice disks like these are thought to form either by ice that gets caught in an eddy in a river and is compacted into a circle while the water swirls, or ice that gets caught in an eddy as a sheet and then is rounded by collision with surrounding ice. The fact that there is an outer layer on this disk makes me think that outer layer has been accreted to the spinning disk as ice fell into a stationary eddy in this case. 

Black Holes: Monsters in Space

This artist’s concept illustrates a supermassive black hole with millions to billions times the mass of our sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies. (Smaller black holes also exist throughout galaxies.) In this illustration, the supermassive black hole at the center is surrounded by matter flowing onto the black hole in what is termed an accretion disk. This disk forms as the dust and gas in the galaxy falls onto the hole, attracted by its gravity.

Also shown is an outflowing jet of energetic particles, believed to be powered by the black hole’s spin. The regions near black holes contain compact sources of high energy X-ray radiation thought, in some scenarios, to originate from the base of these jets. This high energy X-radiation lights up the disk, which reflects it, making the disk a source of X-rays. The reflected light enables astronomers to see how fast matter is swirling in the inner region of the disk, and ultimately to measure the black hole’s spin rate.

Image credit:
NASA/JPL-Caltech

cosmic witchcraft 101: venusian magick ♀

Venus is the second planet from the Sun. Most likely the planet formed through disk accretion - gravitational forces drawing dust and particles together to form a rocky core, which gets big enough to capture the lighter elements that form the planet’s atmosphere. Astronomer Giovanni Cassini reported a moon on venus in the 1600′s, and many people claimed to see it over the next 200 years. Most of these sightings were proven to be nearby stars, but scientists believe Venus had a moon in our solar system’s earlier years. They hypothesize a huge impact on Venus created a moon billions of years ago, but 10 million years after its formation another huge impact reversed the planet’s spin direction and caused the moon to spiral inward until it collided with Venus.

Facts:

  • Venus is the 3rd brightest object in the sky after the Sun and Moon.
  • Incredibly thick, reflective clouds of sulfuric acid cause the planet to shine so brightly.
  • Due to its runaway greenhouse effect, Venus is the hottest planet in the solar system.
  • A Venusian day is 243 Earth days, 18 days longer than a Venusian year.
  • Venus spins backward compared to the other planets. From its surface, the Sun would appear to rise in the west and set in the east.
  • Venus is the most spherical of all the planets.

Magickal Correspondences*

Colors: red, pink, white, green, yellow, purple

Intents: love, self-love, glamors, balance, peace, creativity, attraction, beauty, justice, material comfort, finances, reversal of fortune

Herbs: vanilla, rose, poppy, peppermint, daffodil, juniper, hibiscus, heather, tansy, lilac, violet, myrrh, eucalyptus

Crystals: emerald, rose quartz, blue calcite, jade, green jasper, lapis lazuli, sodalite, turquoise, rhodonite, serpentine, celestite

*some of these correspondences are based on traditional associations and some are based on my personal associations

HUBBLE FINDS THAT THE NEAREST QUASAR IS POWERED BY A DOUBLE BLACK HOLE

Astronomers using NASA’s Hubble Space Telescope have found that Markarian 231 (Mrk 231), the nearest galaxy to Earth that hosts a quasar, is powered by two central black holes furiously whirling about each other.

The finding suggests that quasars – the brilliant cores of active galaxies – may commonly host two central supermassive black holes that fall into orbit about one another as a result of the merger between two galaxies. Like a pair of whirling skaters, the black-hole duo generates tremendous amounts of energy that makes the core of the host galaxy outshine the glow of the galaxy’s population of billions of stars, which scientists then identify as quasars.

Scientists looked at Hubble archival observations of ultraviolet radiation emitted from the center of Mrk 231 to discover what they describe as “extreme and surprising properties.”

If only one black hole were present in the center of the quasar, the whole accretion disk made of surrounding hot gas would glow in ultraviolet rays. Instead, the ultraviolet glow of the dusty disk abruptly drops off towards the center. This provides observational evidence that the disk has a big donut hole encircling the central black hole. The best explanation for the observational data, based on dynamical models, is that the center of the disk is carved out by the action of two black holes orbiting each other. The second, smaller black hole orbits in the inner edge of the accretion disk, and has its own mini-disk with an ultraviolet glow.

“We are extremely excited about this finding because it not only shows the existence of a close binary black hole in Mrk 231, but also paves a new way to systematically search binary black holes via the nature of their ultraviolet light emission,” said Youjun Lu of the National Astronomical Observatories of China, Chinese Academy of Sciences.

“The structure of our universe, such as those giant galaxies and clusters of galaxies, grows by merging smaller systems into larger ones, and binary black holes are natural consequences of these mergers of galaxies,” added co-investigator Xinyu Dai of the University of Oklahoma.

The central black hole is estimated to be 150 million times the mass of our Sun, and the companion weighs in at 4 million solar masses. The dynamic duo completes an orbit around each other every 1.2 years.

The lower-mass black hole is the remnant of a smaller galaxy that merged with Mrk 231. Evidence of a recent merger comes from the host galaxy’s asymmetry, and the long tidal tails of young blue stars.

The result of the merger has been to make Mrk 231 an energetic starburst galaxy with a star-formation rate 100 times greater than that of our Milky Way galaxy. The infalling gas fuels the black hole “engine,” triggering outflows and gas turbulence that incites a firestorm of star birth.

The binary black holes are predicted to spiral together and collide within a few hundred thousand years.

Mrk 231 is located 600 million light-years away.

Jupiter a "failed star"

   astronomy has developed a lot.scientists have studied almost all planets.they are trying to figure out the formation of the planets.by doing so the came to know that the formation of  jupiter, “the king of all planets” was a little bit different. jupiter’s  formation initially, likely to be a star but a very different manner than stars form.thus it was called a “failed star”.

formation of stars

  Stars form directly from the collapse of dense clouds of interstellar gas and dust. Because of rotation, these clouds form flattened disks that surround the central, growing stars. After the star has nearly reached its final mass, by accreting gas from the disk, the leftover matter in the disk is free to form planets.  

a different jupiter

Jupiter is generally believed to have formed in a two-step process. First, a vast swarm of ice and rock ‘planetesimals’ formed. These comet-sized bodies collided and accumulated into ever-larger planetary embryos. Once an embryo became about as massive as ten Earths, its self-gravity became strong enough to pull in gas directly from the disk. During this second step, the proto-Jupiter gained most of its present mass (a total of 318 times the mass of the Earth). Soon thereafter, the disk gas was removed by the intense early solar wind, before Saturn could grow to a similar size.          

brown dwarf      

 brown dwarfs may look like planets but they form like stars–that is, they collapse directly from a gas cloud, rather than building up in the disk around a star. Brown dwarfs lack sufficient mass to shine, so they might more fairly be described as “failed stars.“   

why jupiter?

                jupiter is formed  of same elements such as hydrogen,helium as of the sun,but it is not massive enough pressure and temperature to fuse hydrogens to form helium ,which is the power source of stars. 

binary star system

if jupiter had become a star,our solar system would have become a binary star system.a binary star system is those systems having two stars.they both revolve around themselves in their own orbits.it is interesting to note that most of the solar systems in the universe are binary,triple or higher multiple star systems but our sun is rather unusual.it is the sun which grabbed most of the mass during the formation of solar system.this made jupiter a failed star while in other systems the masses are more equitably distributed
thus its still mysterious, scientists are trying to fathom these mysterious details of the birth process.

source:scientific american

pc :nasa,wikipedia

#science#space#astronomy#nasa

Cataclysmic Dawn: Will this dawn bring another nova? Such dilemmas might be pondered one day by future humans living on a planet orbiting a cataclysmic variable binary star system. Cataclysmic variables involve gas falling from a large star onto an accretion disk surrounding a massive but compact white dwarf star. Explosive cataclysmic events such as a dwarf nova can occur when a clump of gas in the interior of the accretion disk heats up past a certain temperature. At that point, the clump will fall more quickly onto the white dwarf and land with a bright flash. Such dwarf novas will not destroy either star, and may occur irregularly on time scales from a few days to tens of years. Although a nova is much less energetic than a supernova, if recurrent novas are not violent enough to expel more gas than is falling in, mass will accumulate onto the white dwarf star until it passes its Chandrasekhar limit. At that point, a foreground cave may provide little protection, as the entire white dwarf star will explode in a tremendous supernova. via NASA

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Astroquizzical: does a black hole have a shape?

“Does a black hole have a shape? Is there a front and back or side view? Does it look the same from all vantage points?”

When you think about a black hole, you very likely think about a large amount of mass, pulled towards a central location by the tremendous force of gravity. While black holes themselves may be perfectly spherical (or for rotating black holes, almost perfectly spherical), there are important physical cases that can cause them to look tremendously asymmetrical, including the possession of an accretion disk and, in the most extreme case, a merger with another black hole.

youtube

How can scientists study a faraway black hole that emits no light? By observing its quasar. As objects get pulled onto the accretion disk orbiting a supermassive black hole, friction creates a bright light known as a quasar. In this video, researchers use a “galaxy-sized lens” to analyze light from a distant quasar—revealing a supermassive black hole with a truly voracious appetite! See more Science Bulletins here