Comments on: Astronomers see ANOTHER star ripped apart by a black hole!

By: Andrew Planet

Andrew Planet — Thu, 16 Aug 2012 22:12:25 +0000

Excellent article, again. I hope the day will soon come when we’ll be able to go beyond the dogma that nothing can escape a black hole. Black hole energy jets are well documented as travelling well beyond the gravitational pull of the black holes that produce them, originally being pulled in from their accretion discs. I have not read my latter point of view anywhere but I think it’s self evident

By: Science with Pan-STARRS | J. Roald Smeets

Science with Pan-STARRS | J. Roald Smeets — Sun, 01 Jul 2012 23:20:21 +0000

[...] Astronomers see ANOTHER star ripped apart by a black hole! (blogs.discovermagazine.com) [...]

By: Black Hole Feeds on Star « Space « Science Today: Beyond the Headlines

Black Hole Feeds on Star « Space « Science Today: Beyond the Headlines — Mon, 07 May 2012 23:10:09 +0000

[...] The Bad Astronomer explains the details in Discover: [...]

By: Monday Link Review | Knovel Blog

Monday Link Review | Knovel Blog — Mon, 07 May 2012 15:50:05 +0000

[...] 5. Photos: Another Star Ripped Apart By a Black Hole. Because it never gets old, does it? [...]

By: Star Shredded by a Black Hole « Archimedes' Archive

Star Shredded by a Black Hole « Archimedes' Archive — Mon, 07 May 2012 03:56:47 +0000

[...] http://blogs.discovermagazine.com/badastronomy/2012/05/02/astronomers-see-another-star-ripped-apart-… Like this:LikeBe the first to like this post. [...]

By: Carl Coker

Carl Coker — Sat, 05 May 2012 01:33:00 +0000

Jim, your first guess would be correct. I don’t remember the exact number off the top of my head, but there’s somewhere north of 30 magnitudes of extinction in visible and UV light towards the galactic center. What this means is that if you presume the flare would be as bright as Sirius is in our sky if it were to occur in the MW (so, if it appeared as -1.5 visible mag) without all the dust and stuff in the way, it would be about 29th magnitude in reality, or about a trillion times fainter. You would see quite a bit of IR, radio, and X-ray, but the visible and UV light would be almost totally obscured.

Just as a quick calculation, though, the absolute visible magnitude of the MW is -20 or so. 350 times brighter would make it -26 or -27. So, add on the 30 magnitudes of extinction I mentioned, and that comes out to about 3rd or 4th magnitude, but that’s still at only 10 parsecs away (32.6 light years). If instead we put it at the galactic center, ~8.5 kiloparsecs away, that drops to 17th or 18th magnitude, which is pretty faint. The apparent IR emission would be much brighter, since there’s much less extinction in the IR, but still not anywhere near enough to affect us in the slightest.

By: Did It Want Fries With That? « From This Litter Box

Did It Want Fries With That? « From This Litter Box — Thu, 03 May 2012 23:30:38 +0000

[...] http://blogs.discovermagazine.com/badastronomy/2012/05/02/astronomers-see-another-star-ripped-apart-… [...]

By: In Lack of a Better Title – You Know What This Post is, Don’t You? « Rebecca's Corner

Thu, 03 May 2012 21:43:28 +0000

[...] 1: Astronomers see ANOTHER star ripped apart by a black hole! – Discovery Magazine / Bad Astronom… [...]

By: Jim Johnson

Jim Johnson — Thu, 03 May 2012 19:24:15 +0000

Phil, you probably get this sort of question all the time, but I wasn’t able to figure it out myself from my sources (Google). What could we expect to experience when next a star is pulled apart by the Milky Way’s supermassive black hole (if we’re still here when it happens)?

When I read, “… the ultraviolet light from this galaxy flared 350 times brighter than it was before!” the question popped into my head.

I figured I could just find out how much ultraviolet light reaches earth from our own galaxy (the sun excluded) & multiply that by 350, and have a ballpark answer – which I expected to still be far below the the threshold received from our sun.

However, I haven’t been able to find how much ultraviolet light does reach us from the Milky Way. Some sites do provide info on how much starlight (which I assume to mean light in the visible spectrum) reaches earth, from which my calculations – bear in mind that my math is prone to mistakes – show that if such an event produced VISIBLE light 350 times brighter than the whole galaxy and it was not blocked by anything, then it would be about 7 % of the moon’s brightness by the time it reached us.

However, even if the source & my math are both correct, that calculation makes several assumptions that I haven’t been able to verify, besides which I haven’t been able to find out what percentage of total starlight hitting earth is from within our galaxy, whether the 350X multiplier is anything close to representative, or if the star-ripping events emit light at other spectrums than ultraviolet. Even if correct, it doesn’t tell ALL the effects we’d witness in such an event, so finally I gave up and came here to ask the question.

My guess was that the answer would be something like “the event would be detectable in the infrared but hidden in the visible spectrum and ultraviolet by the dust at the center of our galaxy”, but then I went back & re-read your posts from the earlier event, found this line, “It literally makes the hair on the back of my neck stand up. I’m glad this happened billions of light years away.”, and now I don’t know what to guess. But I’m still curious.

By: Richard Drumm The Astronomy Bum

Richard Drumm The Astronomy Bum — Thu, 03 May 2012 18:11:47 +0000

By the way, Here is a finder chart for the Black Hole that swallowed the Red Giant. It’s near the USNO star marked in red, in Camelopardalis.
Which is good, because NOTHING EVER HAPPENS in Camelopardalis…
;^)

http://www.flickr.com/photos/24473498@N02/6993427106/sizes/l/in/photostream/