Birth of Black Hole Possibly Being Observed

TheTXLibra writes "Robert Roy Britt reports on Space.com that we may now be witnessing the earliest stages of black hole development. Star SN 1986J, began to collapse in 1983 into a neutron star, resulting in a supernova explosion in 1986. If the mass of the neutron star reaches 1.4 times the mass of Earth's Sun, it will theoretically collapse into a black hole, if not, it will stabilize as a neutron star."

Comments

Re:Not quite accurate.

[Hungus]

You are pissing over 3 years? Read the article and you can derive that it supposedly went nova over 31 million years ago. We are just now seeing/detecting it from 1982/3 on. Oh and the reason it wasn't "seen" was because the frequency of the emmisions.

SN 1986J was so bizarre that it was serendipitously discovered first in the radio, and afterwards in the optical. Therefore, the precise date of its explosion is not known, but on the basis of the available radio and optical data sn 1986j has been estimated to have exploded around the end of 1982, or the beginning of 1983

Re:Holes?

[Hungus]

Because "Gravastars" are still very much a new and thus fringe theory.

Re:Not quite accurate.

[beeplet]

Also, the collapse into a neutron star or black hole would have been almost instantaneous... So we're not exactly watching the NS/BH being born - more like waiting for the dust to clear so we can see what's in there.

Knowing where to look...

[beeplet]

The article didn't even mention one of the most important reasons this is interesting - so far the only stellar-mass blackhole candidates are in binary systems (where you can infer the mass of an unseen object from the orbit of the visible star). Otherwise, you can't see find a black hole unless you know where to look - and now we do.

(I guess you could also theoretically look for black holes by their gravitational lensing effects, but you would have to monitor a huge number of stars and hope that a black hole intercepts your line-of-sight to one of them, so not very practical.)

Re:Holes?

[Christopher Thomas]

You're promising not to reply to my posts, now please STOP DOING IT.

Fine. _I'll_ reply.

Gravastars are an interesting idea, but they:

a) Propose modifications to physics (the phase transition that gives rise to a different type of space in the interior).

and

b) Attempt to solve a problem that doesn't necessarily exist (embodiment of entropy in black holes, which string theory takes a fairly good stab at explaining).

Thus, I'm skeptical of claims that gravastars exist, barring observations supporting their existance or wider acceptance by the scientific community.

At least in the paper I've managed to dig up so far, they acknowledge many othe potential models of how black holes work, and suggest types of observations that would help determine whether their model is accurate (i.e., they don't claim it's the One True Model off the bat). This is one of the hallmarks of good science.

Observations to look for are gravity-wave signatures of resonance modes in the stiff shell surrounding the gravastar, and optical signatures of impacting matter interacting with this shell. The first should be possible when we get sufficiently sensitive gravity wave detectors online, and the second should be possible from observations of accretion disks in known black hole/other star binary pairs once Mazur and Mottola have worked through the math to figure out what the observational signatures should _be_. Thirdly, if you could get close enough to take good measurements, you'd be able to distinguish between gravastar-type black holes and Hawking-Bekenstein black holes by different radiation signatures coming off of them, but that requires being right next to the hole and having instruments sensitive enough to detect very faint, low-frequency thermal radiation.

In summary, claiming that the gravastar model _is_ what black holes are is very, very premature.