Sagittarius A* in 60 Seconds [HD]

Astronomers have long known that the supermassive black hole at the center of our Milky Way galaxy is a particularly poor eater. The fuel for this black hole, known as Sagittarius A* (or Sgr A* for short), comes from powerful winds blown off nearby stars. Scientists have previously calculated that Sgr A* should consume about one percent of the fuel carried in the winds. However, it now appears that Sgr A* consumes much less than even that. It only ingests about one percent of that one percent. Why does it consume so little? A theoretical model based on these new deep data seen in this Chandra image may provide the answer. It turns out that there is an inner and outer region around the black hole. Pressure flowing outward causes nearly all of the gas to move away from the black hole. This in turn starves the black hole of much of its fuel, and this is why astronomers have seen so little activity from this, our closest supermassive black hole.

credit: NASA / Harvard-Smithsonian Center for Astrophysics

source: http://chandra.harvard.edu/resources/podcasts/hd/index.html

Category:

Science & Technology

Tags:

• Chandra
• x-ray astronomy
• Sagittarius A*
• milky way
• black hole

[kitten313131]

Glad to hear that the nearest all-devouring monster isnt very hungry. I think that is good news. How far away is it anyway? (in case it changes its mind)

[djxatlanta]

It's 26,000 light years away... which is 153 quadrillion miles. There are closer black holes to Earth, but there are no black holes that pose any danger to our solar system, nor are there any large stars in our vicinity that could collapse into black holes.

[soma115]

It strikes me with every new discovery - universe is made to sustain itself. Even might black hole has limits of how much it can digest.

Maybe there is no dark energy, maybe mechanism like this speeding up expansion.

[djxatlanta]

These are completely different processes... in the case of supermassive black holes at the center of galaxies, when the black hole is in the midst of a feeding frenzy, the black hole pushes surrounding matter away from itself via winds, thus causing the black hole to die down -- it's a cyclical affair. Dark energy is proposed to explain the accelerating expansion of the universe.

[soma115]

I know. I just think that dark energy may not be responsible for increasing expansion speed. There are super-novas, north/south black hole jets, solar wind (blowing h2 away) and a wind from black hole - lots of matter going away from heavy objects. But that is just my theory.

One thing you said is new for me - where you found information about cycles in black hole?