The Milky Way's black hole may spring to life in 2013

http://arstechnica.com/science/news/2011/12/the-milky-ways-black-hole-may-spring-to-life-in-2013.ars

by evo_9 • 15 years ago

85 43 15 years ago

AznHisoka• 15 years ago

Could someone explain the implications of all this in laymen terms? Are we in deep shit?

ethanpoole• 15 years ago

No. From what I understand, any material caught in the accretion disk is merely funnelling down into the black hole's event horizon, i.e. the centre. It will not affect any orbiting bodies, such as our solar system, but it will make the black hole pseudo-visible to astronomers because the material in the accretion disk will admit some light.

michaelcampbell• 15 years ago

It will add mass to the black hole though, right? So that will affect orbits, no? Or is that just so infinitesimally small that it can reasonably be ignored?

polyfractal2• 15 years ago

In addition to the other explanations given, it won't affect us presently because it already happened a long time ago.

awj2• 15 years ago

If I send a slow, waddling mobster to go break your kneecaps, are you affected when I give the order or two weeks later when Guido knocks on your door?

Florin_Andrei2• 15 years ago

No.

But the accretion disk might appear visible to various instruments.

Basically, we will see the exact location of the black hole for the first time directly. Not the collapsar itself, of course, but the swirling disk surrounding it.

william42• 15 years ago

Considering the lightyears involved, I assume this means we'll see it in 2013?

hendler• 15 years ago

Was thinking the same thing. Depending on how you think about space-time it "is" happening 27,000 years go.

http://en.wikipedia.org/wiki/Milky_Way#Galactic_Center

swombat• 15 years ago

Or rather, it is happening now 27k light-years away.

sephlietz• 15 years ago

Presumably, yes. It would be odd for the astronomers to use two different temporal points of reference; time of observation is the only time that matters. Plus, any excitement on the part of astronomers would be super pointless if they had to wait another 24824 years to observe it.

jarin• 15 years ago

From the point of view of a photon originating in that gas cloud, it was emitted by an electron in the gas cloud and absorbed by an electron in the telescope sensor at the exact same instant.

finnw• 15 years ago

On the other hand it would be impressive if they correctly predicted it from 24-millenia-old data.

rbanffy• 15 years ago

That's correct. But never forget the idea of a "now" is deeply tied to a "here".

rufibarbatus2• 15 years ago

Implying whatever happened so many thousand years ago will have an impact here at about the same time we observe it happening from here? (I.e. light coming from that time and direction arrives here at about the same time as whatever implication this has to us does.)

If so, what kinds of implications would this have to us? Is this quasar radiation merely an observable thing, or could it disturb communications or something along those lines?

Edit: no doomsday paranoia implied. :-)

Florin_Andrei2• 15 years ago

Think of it as the "egocentric" rule of astronomy: always describe things from the perspective of the observer (you), not from the perspective of the agent.

davidhansen• 15 years ago

That may be about to change, however. Astronomers have spotted a cloud of gas with a mass about three times that of Earth that's on a trajectory that will have it pass close to Sgr A in 2013*

If this is for real, I am ridiculously humbled by the power of modern astronomy. It's pretty damned amazing to me that we have the ability to detect the location, dimension, and trajectory of a mere 3 earth-masses of thin, amorphous gas 27k light years away, in the noisiest and densest part of the galaxy.

johno215• 15 years ago

Based on the Nature article abstract images it appears they were able to image the cloud using the VLT telescope. I got confused about L'-band for a second. Thought they were talking about L-band.

Feel free to correct me if someone has read the article.

[1] http://www.nature.com/nature/journal/vaop/ncurrent/full/natu...

[2] http://www.eso.org/public/teles-instr/vlt.html

[edited for mistake]

Tuna-Fish• 15 years ago

This is the public webcast of the ESO VLT on the issue. http://www.youtube.com/watch?v=YFLkewQIzoA&feature=youtu...

I'd just like to point out that seeing that cloud isn't actually nearly as hard as getting direct observations of planets around other stars. The cloud is very brightly lit by all the stars around it, and is far enough from other light sources that you can just point a telescope at it without needing any tricks. Contrast this to looking at much dimmer planets that are very close to very bright stars. And we've been able to do that for big enough planets since 2008.

tikhonj• 15 years ago

Can somebody explain why the black hole at the center of our galaxy is called "Sgr A*"? Is there some system behind the name or are astronomers just like programmers in naming stuff (it took me a while to figure out how to pronounce nginx >:().

gruturo• 15 years ago

That stands for Sagittarius A* http://en.wikipedia.org/wiki/Sagittarius_A*

walexander• 15 years ago

Sgr is short for Sagitarrius, a constellation. If you mark off the boundary of Sagitarrius, Sgr A* would be in that region. The black hole itself does not have the name, but rather the radio source associated with it. (conjecture alert)I'm not sure where the * comes from, but I believe the A is associated with the fact that Sgr A is a super nova remnant. Supernova are typically named "SN [year] [alpha]" where [year] is the year discovered and [alpha] is an alphabetical character in order of discovery. A supernova remant wouldnt have a year associated, so i'm guessing it's given a constellation and then alphabetical marking.

Typically, astronomers have a mix of common names and many systematic naming schemes, but they get obsoleted when better instruments find darker objects. There was once a catalog of nebula called Messier with about 130 objects (M1,M2,..). We still use these designations, but suddely they found thousands more of these objects and had to rename using the New General Catalog, (NGC1,NGC2,NGC496). Even further the IC goes into many thousands.

For constellations, stars in each constellation are usually named alphabetically with greek chars in terms of their apparent brightness. Alpha Centauri is the brightest star, for example, in Centarus. Then there are common names like Polaris, the north star, whch is alpha ursa minoris.

nknight• 15 years ago

> There was once a catalog of nebula called Messier

Hah, I'd sort of known what the Messier catalog was, but you inspired me to look at its Wikipedia page[1]. Apparently Charles Messier was looking for comets, and was tired of getting distracted by things that weren't comets. M1 is the Crab Nebula[2].

This amuses me.

[1] http://en.wikipedia.org/wiki/Messier_object [2] http://en.wikipedia.org/wiki/List_of_Messier_objects

jmmcd• 15 years ago

It stands for "Signor A*", in order to show it proper respect. I'm glad to see that in this crude age, our astronomers still have class.

ars2• 15 years ago

I wonder if they took time dilation into account when calculating the arrival date.

ypcx• 15 years ago

This is absolutely shockingly awesome. (No I don't use these words often at all.) Based on the non-mainstream scientific evidence, the coming radiation has the power to completely reconfigure our DNA, and in fact all DNA/RNA on Earth's surface. This is what had been predicted by numerous ancient cultures including Mayans, and badly misinterpreted as the end of the world, or end of the times. If you don't happen to be a hardline mainstream scientist, I really recommend picking up this book, if for nothing else, then for all the absolutely shocking scientific research it references: http://www.amazon.com/dp/0525952047/

The Milky Way's black hole may spring to life in 2013

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