Comments on: More on NGC 1316 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/ I am an astronomer, writer, and skeptic. I likes reality the way it is, and I aims to keep it that way. My real name is Phil Plait, and I run the Bad Astronomy blog. Tue, 14 Feb 2012 14:37:42 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: SF Reader http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24225 SF Reader Tue, 28 Nov 2006 16:22:34 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24225 As an add-on to Gary's idea, what do the jets from the core black hole do to stars in their path? Are those SNs in that path, perhaps? It's clearly been going on for quite some time, given the size of the plumes. As an add-on to Gary’s idea, what do the jets from the core black hole do to stars in their path? Are those SNs in that path, perhaps?

It’s clearly been going on for quite some time, given the size of the plumes.

]]> By: lamacher http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24224 lamacher Thu, 23 Nov 2006 21:52:46 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24224 Brings up a question: does anyone know what the killing range for a SN is? For eg, if Betelgeuse at 500 LY or so has already blown up, what is the outlook for this solar system? Brings up a question: does anyone know what the killing range for a SN is? For eg, if Betelgeuse at 500 LY or so has already blown up, what is the outlook for this solar system?

]]> By: Mungascr http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24223 Mungascr Thu, 23 Nov 2006 14:09:03 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24223 Yep, its an unusal galaxy alright but it does (as someone here already mentioned) remind me quite a bit of Centaurus A (Which also has an NGC designation that I can't recall from the top of my head.) I wouldn't be rude about a galaxy that was so exceptional and showing such generosity with its supernova displays Phil! I'd say it was a standout or exceptionally cool galaxy rather than a weirdo and as for the er..crud ... it swallowed and ejected I think there are better ways you could phrase it. After all we don't want to hurt its feelings do we??? ;-) Yep, its an unusal galaxy alright but it does (as someone here already mentioned) remind me quite a bit of Centaurus A (Which also has an NGC designation that I can’t recall from the top of my head.)

I wouldn’t be rude about a galaxy that was so exceptional and showing such generosity with its supernova displays Phil!

I’d say it was a standout or exceptionally cool galaxy rather than a weirdo and as for the er..crud … it swallowed and ejected I think there are better ways you could phrase it.

After all we don’t want to hurt its feelings do we??? ;-)

]]> By: tacitus http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24222 tacitus Thu, 23 Nov 2006 03:40:42 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24222 Carl, interesting comments. As I mentioned in my previous comment, I would think that the supernova scenario would only be practical if the civilization had spread over an appreciable amount of the host galaxy. In that case, the use of a few thousands of stars in this manner, or even a million or two, in parts of the galaxy far enough away from the inhabited areas. And it likely would only happen if the civilization had exhausted other avenues for detecting and communicating with other intelligent life in nearby galaxies. If civilizations are really so rare that only a small percentage of galaxies are host to a single successful intelligent species (I think not likely, but it's possible) then what better way to advertise your presence than to light a few beacons that can be seen from half-way across the Universe? Sure it would be a long shot, but if you've accomplished everything else as a civilization except make contact with another, then I suspect you might go to extraordinary lengths trying. I agree it's not likely, but you never know.... :-) Carl, interesting comments. As I mentioned in my previous comment, I would think that the supernova scenario would only be practical if the civilization had spread over an appreciable amount of the host galaxy. In that case, the use of a few thousands of stars in this manner, or even a million or two, in parts of the galaxy far enough away from the inhabited areas.

And it likely would only happen if the civilization had exhausted other avenues for detecting and communicating with other intelligent life in nearby galaxies. If civilizations are really so rare that only a small percentage of galaxies are host to a single successful intelligent species (I think not likely, but it’s possible) then what better way to advertise your presence than to light a few beacons that can be seen from half-way across the Universe?

Sure it would be a long shot, but if you’ve accomplished everything else as a civilization except make contact with another, then I suspect you might go to extraordinary lengths trying.

I agree it’s not likely, but you never know…. :-)

]]> By: ioresult http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24221 ioresult Wed, 22 Nov 2006 22:11:16 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24221 All this reminds me of the Known Space sci-fi universe of Larry Niven where the center of our own milky way is undergoing a chain reaction of catastrophic supernovae. The shockwave will reach the ficticious Earth in 20k years. I'm wondering what could possibly cause such a chain reaction... a supergiant black-hole merger creating a gravitational shockwave that would precipitate the collapse of surrounding stars? Wow, such imagination! All this reminds me of the Known Space sci-fi universe of Larry Niven where the center of our own milky way is undergoing a chain reaction of catastrophic supernovae. The shockwave will reach the ficticious Earth in 20k years. I’m wondering what could possibly cause such a chain reaction… a supergiant black-hole merger creating a gravitational shockwave that would precipitate the collapse of surrounding stars? Wow, such imagination!

]]> By: ioresult http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24220 ioresult Wed, 22 Nov 2006 22:07:08 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24220 PeterV, dust is heavy elements created in previous supernovae. I think the generic term refers to a mix of light gaseous elements and solidified grains made of condensed heavy elements. In any case, "dust" is only visible because it absorbs light, so it appears dark against a bright background. A young galaxy is still full of dust and gas, but an old galaxy has seen all its dust condensate in planemos (planets not orbiting any star), brown dwarfs or red dwarfs. So, other people, do I get it right? PeterV, dust is heavy elements created in previous supernovae. I think the generic term refers to a mix of light gaseous elements and solidified grains made of condensed heavy elements. In any case, “dust” is only visible because it absorbs light, so it appears dark against a bright background. A young galaxy is still full of dust and gas, but an old galaxy has seen all its dust condensate in planemos (planets not orbiting any star), brown dwarfs or red dwarfs.

So, other people, do I get it right?

]]> By: Carl R. Sams http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24219 Carl R. Sams Wed, 22 Nov 2006 21:19:00 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24219 tacitus- While the idea of detonating super-nova sounds technically possible for a greatly advanced civilization, it would also seem like such a waste. Assuming the c=top speed rule, then these stars are going to be the greatest source of energy in a civilizations immediate area, and therefore any civilization able to blow up stars is likely to be harnessing them for energy ,Type II civilizations on the Kardashev scale. It would be analagous to us gathering all the fosil fuels on Terra, putting them in one spot, and lighting the mother of all signal fires "just in case". Gonna go with probably not on this one. tacitus-

While the idea of detonating super-nova sounds technically possible for a greatly advanced civilization, it would also seem like such a waste. Assuming the c=top speed rule, then these stars are going to be the greatest source of energy in a civilizations immediate area, and therefore any civilization able to blow up stars is likely to be harnessing them for energy ,Type II civilizations on the Kardashev scale. It would be analagous to us gathering all the fosil fuels on Terra, putting them in one spot, and lighting the mother of all signal fires “just in case”. Gonna go with probably not on this one.

]]> By: Carl R. Sams http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24218 Carl R. Sams Wed, 22 Nov 2006 21:16:09 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24218 tacitus- While the idea of detonating super-nova sounds technically possible for a greatly advanced civilization, it would also seem like such a waste. Assuming the c=top speed rule, then these stars are going to be the greatest source of energy in a civilizations immediate area, and therefore any civilization able to blow up stars is likely to be harnessing them for energy ( Type II civilizations on the Kardashev scale ). It would be analagous to us gathering all the fosil fuels on Terra (personal preference), putting them in one spot, and lighting the mother of all signal fires "just in case". Gonna go with probably not on this one. tacitus-

While the idea of detonating super-nova sounds technically possible for a greatly advanced civilization, it would also seem like such a waste. Assuming the c=top speed rule, then these stars are going to be the greatest source of energy in a civilizations immediate area, and therefore any civilization able to blow up stars is likely to be harnessing them for energy ( Type II civilizations on the Kardashev scale ). It would be analagous to us gathering all the fosil fuels on Terra (personal preference), putting them in one spot, and lighting the mother of all signal fires “just in case”. Gonna go with probably not on this one.

]]> By: Melusine http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24217 Melusine Wed, 22 Nov 2006 20:35:23 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24217 ^^^ Such <i>unplanetary</i> thoughts! 0-8~ ^^^

Such unplanetary thoughts! 0-8~

]]> By: Mark Martin http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24216 Mark Martin Wed, 22 Nov 2006 19:22:17 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24216 If a large galaxy eats & digests another small galaxy, then where is the larger galaxy's "poop-chute", and what does the stuff coming out the chute look like? Is it all just brown dwarfs? Maybe NGC 1316 is suffering the mother of all stomach flu. If a large galaxy eats & digests another small galaxy, then where is the larger galaxy’s “poop-chute”, and what does the stuff coming out the chute look like? Is it all just brown dwarfs? Maybe NGC 1316 is suffering the mother of all stomach flu.

]]> By: PeterV http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24215 PeterV Wed, 22 Nov 2006 18:18:08 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24215 What is this 'dust' made of? And where does it come from? What is this ‘dust’ made of? And where does it come from?

]]> By: The Bad Astronomer http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24214 The Bad Astronomer Wed, 22 Nov 2006 17:22:00 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24214 <a href="http://www.badastronomy.com/bablog/2006/11/21/more-on-ngc-1316/#comment-79399" rel="nofollow">Kaptain K</a>, I was surprised too, but the stuff I have read (like the Hubble press release linked in the supernova post) has been saying the dust is from the smaller galaxy, so I wrote that. I've been wondering if maybe there was a previous galaxy that got eaten, but I haven't seen any papers about it. I may yet read some more about it. Kaptain K, I was surprised too, but the stuff I have read (like the Hubble press release linked in the supernova post) has been saying the dust is from the smaller galaxy, so I wrote that. I’ve been wondering if maybe there was a previous galaxy that got eaten, but I haven’t seen any papers about it. I may yet read some more about it.

]]> By: Gary Ansorge http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24213 Gary Ansorge Wed, 22 Nov 2006 16:27:50 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24213 I wonder if the influx of gas and dust from the galactic collision might not have been a trigger event for the supernvae, ie, two white dwarves, sitting there, ALMOST ready to go boom and along comes a bunch of "crud" at near light speed, dumping more gas, just enough to tip the stars over the edge. I predict, there could well be more such events in that galaxy in the next few thousand years. If there is, just name the effect after me,,, GAry 7 I wonder if the influx of gas and dust from the galactic collision might not have been a trigger event for the supernvae, ie, two white dwarves, sitting there, ALMOST ready to go boom and along comes a bunch of “crud” at near light speed, dumping more gas, just enough to tip the stars over the edge. I predict, there could well be more such events in that galaxy in the next few thousand years. If there is, just name the effect after me,,,

GAry 7

]]> By: tacitus http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24212 tacitus Wed, 22 Nov 2006 16:16:47 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24212 So if two concurrent supernovae in a single galaxy is merely coincidence, then how many would it take before we would suspect that there was more to it than simple chance? Three? Four? Five? Depends on the precise locations and timing? I ask because it would not be beyond the realms of possibility that a highly advanced civilization (one which had spread galaxy-wide) could use multiple supernovae as a kind of beacon to say "we are here". Sure, it's a very slow and inefficient way to communicate but stars are plentiful and there may be no better way to attract attention from as far as millions of light years away. If it turns out that intelligent life is an extremely rare occurrence then a single civilization might be alone even in a vast eliptical galaxy and, like castaways stranded on a desert island, they could yearn to make contact with others no matter how far the distance. It could also be a way of bootstrapping an escalating scale of communications -- a pattern of exploding stars would certainly attract our attention, and if we observed such an event we would immediately start probing the host galaxy with every advanced instrument we have (and all those yet to come online), looking for some sort of signal. And perhaps we would find a radio signal that contained the information to allow us to build instruments to hook into some local InterGalacticNet we currently have no awareness of... So if two concurrent supernovae in a single galaxy is merely coincidence, then how many would it take before we would suspect that there was more to it than simple chance?

Three? Four? Five? Depends on the precise locations and timing?

I ask because it would not be beyond the realms of possibility that a highly advanced civilization (one which had spread galaxy-wide) could use multiple supernovae as a kind of beacon to say “we are here”. Sure, it’s a very slow and inefficient way to communicate but stars are plentiful and there may be no better way to attract attention from as far as millions of light years away.

If it turns out that intelligent life is an extremely rare occurrence then a single civilization might be alone even in a vast eliptical galaxy and, like castaways stranded on a desert island, they could yearn to make contact with others no matter how far the distance.

It could also be a way of bootstrapping an escalating scale of communications — a pattern of exploding stars would certainly attract our attention, and if we observed such an event we would immediately start probing the host galaxy with every advanced instrument we have (and all those yet to come online), looking for some sort of signal. And perhaps we would find a radio signal that contained the information to allow us to build instruments to hook into some local InterGalacticNet we currently have no awareness of…

]]> By: Terry http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24211 Terry Wed, 22 Nov 2006 15:17:48 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24211 Great post! What I'd like to know is, how long did it take to inflate those huge lobes of matter? I mean, at maximum speed, how long would it take to grow the lobes to their present day dimentions? Great post!
What I’d like to know is, how long did it take to inflate those huge lobes of matter? I mean, at maximum speed, how long would it take to grow the lobes to their present day dimentions?

]]> By: Blake Stacey http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24210 Blake Stacey Wed, 22 Nov 2006 14:50:29 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24210 These posts continue to impress me. Every time I <a href="http://snews.bnl.gov/popsci/contents.html" rel="nofollow">try to explain science</a>, I feel like I have to "begin with the beginning", so I try to start with Galileo Galilei or even Democritus of Abdera. The BA's concise and intuitive writing contains an awful lot of lessons, not just about science but about how to communicate science. (Of course, there's an advantage to beginning your history with Democritus, because the man had wisdom: "I would rather understand one cause than be King of Persia", "A life without festivity is a long road without an inn", and so forth.) These posts continue to impress me. Every time I try to explain science, I feel like I have to “begin with the beginning”, so I try to start with Galileo Galilei or even Democritus of Abdera. The BA’s concise and intuitive writing contains an awful lot of lessons, not just about science but about how to communicate science.

(Of course, there’s an advantage to beginning your history with Democritus, because the man had wisdom: “I would rather understand one cause than be King of Persia”, “A life without festivity is a long road without an inn”, and so forth.)

]]> By: Chris http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24209 Chris Wed, 22 Nov 2006 14:39:10 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24209 BA, Intersting stuff.......supernovae are intersting things to learn about. Off topic a bit, Phil check out the Coast To Coast AM website from Monday. Richard Hoagland is pushing some crap and pictures about ancient ruins on the moon. I thought at first he was a crackpot, but between this and the "C-3P0" Lunar robot pictures he has, I think he is just nuts. BA,

Intersting stuff…….supernovae are intersting things to learn about.

Off topic a bit, Phil check out the Coast To Coast AM website from Monday. Richard Hoagland is pushing some crap and pictures about ancient ruins on the moon. I thought at first he was a crackpot, but between this and the “C-3P0″ Lunar robot pictures he has, I think he is just nuts.

]]> By: Malte http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24208 Malte Wed, 22 Nov 2006 14:07:14 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24208 Anybody good enough at statistics to say what, if anything, this observation could say about the supernova rate in NGC 1316? What are the chances of seeing an elliptical galaxy with two SNe at the one time? Otherwise I think this is one for the News Item of No Scientific Interest bin. I mean, is any astronomer going to write a paper about this? I dunno, maybe there are interesting things you can do if you can get both of them into the same spectrograph slit... Anybody good enough at statistics to say what, if anything, this observation could say about the supernova rate in NGC 1316?

What are the chances of seeing an elliptical galaxy with two SNe at the one time?

Otherwise I think this is one for the News Item of No Scientific Interest bin. I mean, is any astronomer going to write a paper about this? I dunno, maybe there are interesting things you can do if you can get both of them into the same spectrograph slit…

]]> By: Melusine http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24207 Melusine Wed, 22 Nov 2006 12:30:08 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24207 <i>The latest collision dumped a lot of crap onto the central black hole,...</i> You meant to say <i>crud</i>, right? Otherwise, another enlightening post that brought a smile to my face - you may think NGC 1316 is "weird" but the supernovae are <i>super</i> cool! Keep us posted. (-8~ The latest collision dumped a lot of crap onto the central black hole,…

You meant to say crud, right? Otherwise, another enlightening post that brought a smile to my face – you may think NGC 1316 is “weird” but the supernovae are super cool! Keep us posted. (-8~

]]> By: gopher65 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24206 gopher65 Wed, 22 Nov 2006 11:55:51 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24206 Great post:). Great post:).

]]> By: Kaptain K http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24205 Kaptain K Wed, 22 Nov 2006 10:38:34 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24205 BA, Are you sure that the dust is the result of a previous encounter wit the smaller galaxy in the picture? I ask because: 1) The smaller galaxy looks too much like an undisturbed barred spiral to have lost that much dust to its big neighbor. 2) To me, it looks like a more advanced version of Centaurus A, which is in the (final?) stages of digestion of another galaxy. My impression is that the dust is the result of a previous capture of a galaxy, unrelated to the current interaction. BA,
Are you sure that the dust is the result of a previous encounter wit the smaller galaxy in the picture?
I ask because:
1) The smaller galaxy looks too much like an undisturbed barred spiral to have lost that much dust to its big neighbor.
2) To me, it looks like a more advanced version of Centaurus A, which is in the (final?) stages of digestion of another galaxy.

My impression is that the dust is the result of a previous capture of a galaxy, unrelated to the current interaction.

]]> By: Chip http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/comment-page-1/#comment-24204 Chip Wed, 22 Nov 2006 09:08:15 +0000 http://blogs.discovermagazine.com/badastronomy/2006/11/21/more-on-ngc-1316/#comment-24204 Those are amazing images. NGC 1316 is monumentally huge. Colossal! Hypothetically, if our little star and solar system existed somewhere within that massive elliptical galaxy, perhaps in the outer regions but still within NGC 1316, would we live out our existence basically unaffected by all the action around us? (Because we take up a small area, assuming we're not near the super nova). Or – would we eventually find ourselves in hot water – i.e, too much radiation? Just curious. It's a violent universe. Thanks for the interesting insights in your blogs. Those are amazing images. NGC 1316 is monumentally huge. Colossal! Hypothetically, if our little star and solar system existed somewhere within that massive elliptical galaxy, perhaps in the outer regions but still within NGC 1316, would we live out our existence basically unaffected by all the action around us? (Because we take up a small area, assuming we’re not near the super nova). Or – would we eventually find ourselves in hot water – i.e, too much radiation? Just curious. It’s a violent universe. Thanks for the interesting insights in your blogs.

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