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View Full Version : Did V838 Monocerotis Eat Three Jupiters?



Fraser
2006-Jun-23, 05:31 AM
V838 Monocerotis. You might not remember the name, or even be able to pronounce it, but you've seen the pictures. The Hubble Space Telescope first captured images of this amazing star erupting material in 2002, and then photographed it again in subsequent years. A huge cloud of gas and dust, light-years across, is being illuminated before our eyes. But what caused the outburst that set off this explosion? One team of astronomers think we might be looking at the violent deaths of V838 Monocerotis' planets as they're consumed.

Read the full blog entry (http://www.universetoday.com/2006/06/23/did-v838-monocerotis-eat-three-jupiters/)

antoniseb
2006-Jun-23, 01:30 PM
Just as a note for people that don't know. The cloud we see expanding around V838 Monocerotis is not travelling at near the speed of light. That cloud was blasted out of the star[s] thousands of years ago to its current diameter of about five light years, and what Hubble imaged is "light echos" in which the great burst of light from the most recent event (A Jupiter sized planet hitting the star?) sent out a flash of light that we see as a growing spherical surface.

Up till now, I'd imagined that planets falling into a star would get absorbed harmlessly. Now that this article points it out, it would have to be a blast.

jcamjr
2006-Jun-23, 02:11 PM
In recent years I have read a number of articles which tossed around the idea of spiraling gas giants migrating inward and falling into their suns as part of the normal processes that occur in young solar systems. If such is the case would not the implyed energy release of such an event have a profound effect on the structure and evoloution of the forming planetary systems in which they occured?

antoniseb
2006-Jun-23, 03:17 PM
would not the implyed energy release of such an event have a profound effect on the structure and evoloution of the forming planetary systems in which they occured?

That's hard to say. I'm sure there would be some impact, but the recently observed event was a bright flash, and only illuminated material that was already there from a bigger event. I don't know if the light alone would have a large impact on the planet forming disk.

ToSeek
2006-Jun-23, 05:25 PM
As antoniseb indicates, this is a poor description of the situation:


A huge cloud of gas and dust, light-years across, is expanding before our eyes.

We're not seeing the cloud expand but the light illuminate from the center to the outskirts as time goes by.

Fraser
2006-Jun-23, 06:41 PM
I'll rewrite it...

"is being illuminated before our eyes"

ToSeek
2006-Jun-23, 06:53 PM
Much better.

jcamjr
2006-Jun-23, 08:02 PM
If I understand the article correctly a jupiter class giant falling into a star will result in an burst of energy equal to some 600,000 times the output of our sun. Is there any data on the duration of such an event.

antoniseb
2006-Jun-23, 08:38 PM
The flash was fairly brief. In terms of total energy, How fast would Jupiter be going if it fell straight into the Sun? What is 1/2 MV2 for that? We are talking about a lot of energy.

George
2006-Jun-24, 08:09 PM
We're not seeing the cloud expand but the light illuminate from the center to the outskirts as time goes by.
Yes, this is a bit surprising for those new to astronomy; light seems slow out there.

Here is a series of chronological images illustrating the echo growth as seen by the Hubble (http://imgsrc.hubblesite.org/hu/db/2003/10/images/a/formats/web.jpg). [Added: Surprisingly, we are not seeing the gas expand outward, but only the light echo as it propogates outward through the cloud.]

The light echo is reflected off the surface in the shape of an ellipsoid. ngc3314) newest book has a nice section on it.]

The idea of a sudden influx of deuterium from a giant planet causing a monstrous flash is very interesting. Why wouldn't it diffuse in the star's outer shell and only gradually feed the core, allowing its subsequent fusion?

Back in March, this thread (http://www.bautforum.com/showthread.php?t=39606) discusses a favorable model which predicts large solar system planets being swallowed by the sun. Could lower temperature stars also produce a flash of some sort if large planets crashed into them?

newinsight
2006-Jun-26, 12:55 AM
Hello. I am new to the forum, but I have a comment, or more accurately, a question. The bursts appeared in quick succession, yes? Assuming that Jupiter size planets would have widely separated orbits, how would all three planets manage to collide with the stellar surface so rapidly? Perhaps the event was caused from a single object of 3 Jupiter masses having been torn apart into three separate masses by tidal forces which then fell in a spiralling fashion onto the stellar surface. Sort of like the cometary string of pearls that collided with our own Jupiter.

antoniseb
2006-Jun-26, 01:20 AM
Hi Newinsight, and welcome to the BAUT forum.

I have the impression that the three bursts were spread over several hundred years.

George
2006-Jun-26, 02:01 AM
Welcome, Newinsight :clap:

If I read it correctly, it was suggested the first planet caused stellar expansion which subsequently caused the other two to be engulfed.

It is interesting that they consider V4332 Sgr. to be a solar-like star which may have swallowed a planet, too.

Recently, we discussed a new model which has giant protoplanets merging with their host ( by Paul Cresswell and Richard Nelson (http://www.bautforum.com/showthread.php?t=39606)). Perhaps the frequency of these possible events may be greater than those estimated by Retter, et.al.

Would it be appropriate to email them of each other's paper?

bigbluestar
2006-Jun-27, 05:45 PM
well unfortunatly the size of the planet has nothing to do with the location of its orbit. Many jupiter size planets have been found with orbits closer that mercury. Infact these are the planets that are easily detectable because of the small orbit period.

George
2006-Jul-04, 05:50 PM
well unfortunatly the size of the planet has nothing to do with the location of its orbit. Many jupiter size planets have been found with orbits closer that mercury. Infact these are the planets that are easily detectable because of the small orbit period.
I think models indicate a lockstep migration of planets toward, and into, their host star. Resonance is maintained, I think. Once the disk is cleared-out, perhaps, migration stops, leaving an interesting remaining collection of planets depending on early initial conditions.

antoniseb
2006-Jul-04, 06:11 PM
I have the impression that these planets did not collide via migration as such but rather as a chaotic result from the gravity changing when the two host stars collided.

George
2006-Jul-04, 06:11 PM
I almost started a new thread on flashing stars in the Astronomy forum because this seems to be very interesting. Is this idea of planet gulping causing flashes new? If so, are we not seeing a wonderfully new observed behavior?

Is a new thread in the Astronomy forum warranted just for these hypothetical events?

George
2006-Jul-04, 07:37 PM
I have the impression that these planets did not collide via migration as such but rather as a chaotic result from the gravity changing when the two host stars collided.
In the paper it was stated that of seven models, two are favored: the binary merger and the planetary merger scenarios. I believe the paper only addresses the latter.

It does seem likley this is a binary star system with a B class secondary. It is mentioned that the other star may be a contributor to the planetary demise. The gulping of a planet(s) was also proposed in 1999 and by Siess and Levio. Retter also had co-authored one in 2003. After it was discovered planets can exist in binary systems, along came greater credibility for the scenario. If I am reading it correctly, the flashes are attributed to either gravitational energy being released when the planet's plunge reaches a critical density level, or a possible burst of energy from the new deuterium fuel provided by planets; perhaps both.

After enjoying Cresswell's, et.al., paper regarding the likleyhood of numerous planetary consumptions by their protostar due to migrations, as well as the possibility that accretion disks may generate more planets than orginially thought, then perhaps we will see more effort to discover such events.

The paper also states that V838 Mon is the prototype for a new class of objects. Shall we have a naming contest for possible planet eaters? :) Maybe so. This subject is very interesting and, perhaps, another thread should be devoted to these objects.