Posted by Paul LaViolette
January 23, 2014
The American Astronomical Society held several press conference meetings at its 223rd meeting this month near Washington, DC. The January 7th press meeting addressed topics which included the G2 Cloud encounter with the Galactic core. Astronomer Leo Meyer expressed the consensus that the G2 cloud could reach its orbital pericenter (periastron, or point of closest approach to the Galactic core) in just a few months, hence supporting the estimates made by Phifer, et al. and Gillessen, et al. that this point would be reached around March 17th to April 1st, at which point the G2 cloud would be as close as 160 to 200 AU from the Galactic core. Earlier, Eckart, et al. had stated a date as late as May. Starburst is attempting to contact him to get an update on his pericenter date estimate and whether he agrees with the March/April estimate; but no response yet.
One of the responsibilities of the Starburst Foundation is to contact astronomers observing the Galactic center to make them aware of the possibility of the launching of a Galactic superwave. A Galactic superwave is an intense cosmic ray particle barrage, accompanied by electromagnetic radiation and possibly a gravity wave that travels isotropically and rectilinearly outwards from the center of our Galaxy at very close to the speed of light. A superwave can last for less than a year or for up to several thousand years as occurred during the last ice age.
During the past 10 days, I had sent emails to 73 astronomers and astrophysicists who have published papers on the G2 cloud in the past few years, noting that it is now generally accepted that the G2 cloud very likely contains an embedded star, something I have believed to be the case for over a year. But I noted that I was concerned that currently there exist no studies or scientific papers examining what would transpire from the G2 encounter if the embedded star were instead a binary system having a companion star or maybe a jupiter sized planet. I pointed out the high likelihood that a star would have a binary companion or planet and also demonstrated the high likelihood that such a companion would be tidally stripped away from its parent star once the G2 cloud had reached pericenter. I pointed out that if such a stripped off mass were to fall directly into the Galactic core, it could trigger a very large core outburst. Many of these ideas were presented in the last Sphinx Stargate news posting.
I noted in the email that such an outburst would be many orders of magnitude more energetic than the kind of activity normally spoken of which would result from the gradual infall of gas from the G2 cloud. I gave as an example the infall of a one solar mass companion star, that if half of its mass survived this infall, it would impart a kinetic energy of 1053 ergs, the amount of energy in a hypernova. This is about a million times greater than the energy that would be released just from gas from the G2 cloud falling onto the core. By the time it reached a distance of 0.1 AU, the star could attain a velocity of 0.9 c (90% of the speed of light), if the outgoing cosmic ray flux had no appreciable decelerating affect on it. I believe, however, that the star would burst before reaching such a close distance and such a high velocity (as described later in this posting).
In my email I pointed out that if a companion were being stripped from its parent star, it might generate a faint secondary cloud that would be seen to be separating from the main G2 cloud. I asked the astronomers that if their future observations were to show this occurring to please let me know since this could give an advanced indication of the increased likelihood of an energetic core outburst occurring (if this companion should make a direct entry into the core). Considering the time required for the companion to depart from the G2 cloud and travel into the core, one can estimate a travel time of around 4 to 5 months.
two to three weeks (my earlier estimate of 2 - 3 weeks was in error). This would give us some warning so that astronomers could conduct intense study to see whether this companion might make a direct hit, and also (something I did not mention) it could give some lead time to issue a public alert for the increased likelihood of a superwave event.
I acknowledged to them that a stellar split off did not guarantee an ultimate core impact. Other scenarios might be that the star might be flung into a new eccentric orbit about the GC (Galactic center), or might be entirely ejected from the GC vicinity as a high velocity star. These are discussed further below. From the first 15 astronomers I contacted, three wrote back, and all had positive reactions to the idea that a binary star might be present in G2. Here are some of their responses (with the names removed for anonymity):
January 10, 2014
Thanks for sharing your interesting ideas with me. I will let you know if there is any evidence for a split of G2 in the future. I am Cc'ing a postdoctoral fellow, J..., who works with me on G2...
All the best,
January 10, 2014
This is an interesting idea I haven’t heard others discuss. I will keep alert for anything. So far there has not been any activity people can attribute to increased SgrA* accretion but that should take a yr after pericenter I think.
You should post you idea in some journal.
January 10, 2014
This is a very interesting hypothesis!
I would however point out that if the binary system gets disrupted
during the closest encounter, it does not necessarily mean that the
companion star, or any of the stars, fall on to the BH. Stars are very
compact when compared to the gas falling on the Sgr A*. They propagate
through it like a bullet through mist. So one can consider this
encounter as a "regular" disruption of a binary system getting close
to a BH which results in two single objects moving on new orbits, none
of which is likely to "hit" the BH.
On the other point: if G2 cloud is indeed only a stellar wind then it
is unlikely that the wind comes from both stars embedded in the cloud.
Most likely only from one of them. And if this is the case, then after
disruption the companion would not take part of the envelope with it -
the wind ejecta is not gravitationally bound so the star again would
penetrate it like a bullet. Therefore, splitting of the cloud would
Another thing is that G2 cloud/star system is on very elongated orbit.
It must have reached this orbit due to another dynamical interaction.
Such interactions most likely lead to disruptions of binary systems,
however, such a system may survive, under favourable conditions.
I look forward to see what happens with G2 in the nearest future!
Thank you for sharing your thoughts with me,
I share these emails here only to show that most astronomers studying the G2 cloud have not been thinking along this line, even though it is very likely that the G2 cloud may contain a binary or planetary system. In regard to the second astronomer's suggestion as to why don't I post the binary star idea in a journal, the answer is that there is too little time left before something could happen with the G2 cloud/star encounter with Sgr A*. My own experience has been that getting an article published in a refereed science journal takes at a minimum one year and in the case of my well received Astrophysical Journal paper, it took eight years!
In regard to the points brought up by the third astronomer, I reponded to him that I agree with what he says that if a binary is disrupted it does not necessarily imply a direct hit of the Galactic core (see the Galactic pinball paragraph later in this news item). As for a separating cloud not being visible due to the separating companion not generating a separate cloud, I said that I agree that this is true if the companion is much less massive, e.g., a brown dwarf or jupiter sized planet. However, I mentioned that if it is a star, even if ten times less massive than the primary, it should have a stellar wind strong enough to generate a separate cloud signature, although far fainter than the current G2 cloud.
Regarding his comment that the G2 cloud/star should have had a prior stellar encounter which could have gravitationally disturbed a G2 star and possibly dislodged a binary companion, I agree. So if the G2 cloud contains a one solar mass star, the probability that it might have a companion may be 30% instead of 45%. Or if it contains a 10 solar mass primary star, the probability of having a companion star may be 45% instead of 60%. But still these are rather substantial probabilities. Astronomers have known that binary systems have had close encounters with the Galactic core because this is the only way they can explain the finding of hypervelocity stars shooting away from the Galactic core, or of stars circling the core in tight elliptical orbits.
I sent emails to the other 68 astronomers in three successive sets over the six days that followed, but none of them answered which I found very strange. To go from an initial email statistical response of 20% down to 0.00% in the following mailings makes me wonder were those astronomers all too busy to answer or did someone initiate a fire walling of my emails. The next few months are so significantly important that I hope that communication channels with the observers are not being closed down.
At the press conference conducted at the American Astronomical Society meeting held earlier this month near Washington DC, Leo Meyer did briefly consider the possibility that the G2 star may be a "merged binary," that is a single star formed when two stars in a binary system coalesce. But he did not consider the possibility that the embedded star may be a binary system. Although infrared imaging implies some stellar object may be present within G2, it is unable to distinguish whether this is a single star or a binary star system. Astronomers have arbitrarily chosen to discuss only the single star hypothesis.
At the end of the emails I had sent to this group of astronomers, I gave a link to my 1987 paper which describes the galactic superwave phenomenon, which they apparently were not aware of. I am hoping they will take the time to read it.
Meanwhile most astronomers appear to be totally unaware that a Galactic core outburst, if it were to happen, could have an immediate and possibly catastrophic impact on our world civilization. For example, in the video excerpt from the press conference posted below, consider the reporter's question to Dr. Meyer which asks "if we are lucky and get 'fireworks,' what does that entail?" The term "fireworks", which he uses here was earlier used by Dr. Meyer during his presentation as a reference to Galactic core activity resulting from G2 cloud gas falling into the Galactic core. Note that even the reporter is unaware of the dire circumstances that could result from a core outburst since he innocently refers to it as a "lucky" event. Dr. Meyer responds to his question saying that this would simply entail the Galactic core getting much brighter (e.g., in X-ray luminosity) than it currently is. He speaks of this occurrence as something that astronomers are eager to observe since it is something they have not seen happen before.
He fails to mention the one thing that is most important, namely that if this energy release is so large that it triggers a sizable Galactic core cosmic ray outburst, this could result in the launching of a superwave cosmic ray volley that would arrive seconds after the initial visible gamma ray burst and perhaps one or two days after a preceding gravity wave impulse. All of these effects could have a catastrophic impact on modern society. Even a small outburst could produce an EMP shock that could fry satellites and knock out electrical grids around the world. What would be "lucky" for us, to use the reporter's phrase, would be if the infalling material were to trigger an energy release that was of sufficiently low magnitude that it didn't result in a superwave. That is, if the cosmic ray energy intensity of the outburst were sufficiently low, magnetic fields in the vicinity of the Galactic core could trap them in the core's immediate vicinity and prevent them from traveling rectilinearly toward us at near light speed velocity. But if an entire planet or star were to get stripped off and fall in, I am afraid we won't be so lucky.
Dr. Meyer does get close to the idea of cosmic ray expulsion when he refers to the possibility that they might observe jets coming out of the Galactic core. But here he is implying that the cosmic ray emissions would be directed perpendicular to our line of sight toward the Galaxy's poles. He would be making this assumption based on astronomer's past models of jets seen emerging from the cores of certain active radio galaxies which they interpret as incoherent synchrotron emission. However, this model is seriously flawed. As explained in my Ph.D. dissertation and my Earth Moon and Planets paper, the jet like radio images that we see are actually coherent synchrotron radiation produced by cosmic rays traveling towards the observer and relativistically beaming their emission in a tight laser-like beam directed forward towards us along their rectilinear flight path. Cosmic rays actually propagate outward isotropically, but we don't see the emission from the other rays since their synchrotron beaming is not aligned with our line of sight. The above two references support this model with observational data.
Astronomers have made this same jet orientation mistake in their interpretation of the Fermi bubbles. As noted in earlier posting in the Galactic superwave forum, astronomers speaking about the Fermi bubbles ignore the fact that cosmic rays are also propagating isotropically away from the Galactic center producing the diffuse gamma ray emission halo that surrounds our Galaxy (above, behind, and on either side of us). They unwittingly subtract out of the image this very important isotropic component in order to isolate and depict the bubble feature.
If Dr. Meyer, and other GC astronomers, realized that the ultra relativistic cosmic rays being put out by active galactic cores are traveling radially outward in all directions, not just perpendicular to our line of sight, with those in our line of sight coherently beaming their emission directly towards us, they might not speak of such jets in such a relaxed manner. GC astronomers may have forgotten that at the AAS conference held 14 years earlier in January 2000, it was announced that synchrotron emission from the Galactic core was found to be circularly polarized. Only cosmic rays that are traveling directly towards the observer can produce such circularly polarized emission.
To view this press conference question-answer interchange excerpt, click the video below.
The entire press conference, Care and Feeding of Black Holes, may be viewed here.
Some minutes later another member of the media asked Dr. Meyer what would be the probability of having Galactic core fireworks, see below:
Dr. Meyer responds that he feels that it is improbable that they will see "fireworks" at the Galactic center. From the standpoint of public safety, I hope he will be right. But, unfortunately he is not considering all the possibilities. He bases his answer on the assumption that the G2 cloud might contain a single star and assumes that if such a star is present the chances of fireworks will be less probable because a lesser amount of matter would likely be entrained onto the Galactic core. Here he apparently assumes that the presence of a gas-expelling star would lower existing estimates of the mass of gas contained in G2, suggesting that only a "dietary supplement" might then be consumed, as he jokingly puts it.
But, in answering this way, he has completely overlooked the possibility that the G2 cloud might contain a binary star system or a star orbited by a planet or brown dwarf. As mentioned earlier, this would substantially hike the probability of a very energetic event occurring at the Galactic core because a companion star or planet, if present would most likely be tidally stripped off from the parent star and one of the outcomes would be high-speed entry directly into the Galactic core.
So what are the probabilities of such a star/planet entry? This is an important question because it is the primary determiner of whether there will be a highly energetic outburst and superwave release from the Galactic core. As mentioned earlier in this posting, there are three possibilities that might result if a star, brown dwarf, or planet are tidally stripped off the parent star during pericenter passage:
a) One scenario would be that the stripped off body could adopt a new elliptical orbit around the Galactic center as has happened many times in the past and which explains the presence of about 22 known stars which currently travel around the GC in close elliptical orbits; see video below.
b) Another scenario could be that the star or planet is ejected from the vicinity of the Galactic core as a hypervelocity star. Such stars are flung at such high speed that they will eventually leave the Milky Way.
c) A third possibility, the unlucky possibility, is that the star or planet adopts a trajectory that takes it in close to the core resulting in an energetic release that triggers a core outburst.
Coming up with a reasonable probability estimate for outcome (c), requires conducting computer modeling of various trajectories for star/planet companions leaving the primary star which follows the G2 cloud orbital trajectory. In the past several astronomers have written papers describing the results of simulations they have done calculating the outcomes for stripped off companions that follow arbitrary trajectories away from their parent star, and examining this for a variety of pericenter distances and primary star velocities. But, unfortunately, none have carried out such a simulation for a G2 cloud binary companion. I am now inquiring of some of these authors if, based on their modeling experience, they could give some rough estimate of what the probability would be for outcome (c) in the case of a companion body emerging from the G2 cloud. I have not heard back from them yet. Could it be a 10% probability, I don't know.
My own rough seat of the pants estimate is as follows. If the primary star is a few solar masses and the probability of its having a stellar companion is 35%, or having a planet is 80%, then secondly if additionally the probability of tidal stripping is 100%, and thirdly if the probability of core infall is 10%, then multiplying these probabilities we get the following. The probability of a stellar companion triggering a very strong core outburst would be around 3% and the probability of a planet triggering a lesser energetic core event would be maybe 8% (greater if more than one planet were stripped off). For a brown dwarf companion the probability would be somewhere in between these two estimates.
In an earlier posting in May 2013, it was noted that one must take into account a star or planet's internal genic energy production as well as the cosmic ray heating of its surface by the Galactic core wind in order to compute its stellar luminosity. At a distance of 130 AU from the Galactic core, it was estimated there that a one solar mass star would acquire a luminosity of 14 solar luminosities just due to cosmic ray heating. If this star were to approach to within a distance of 20 AU and if its diameter correspondingly expanded 10 fold to 40 solar radii, typical of a hot blue giant star, cosmic ray heating of its surface would cause the star's luminosity to rise an additional 4200 fold, giving it a total luminosity of ~60,000 solar luminosities which is well beyond its Eddington limit of about 30,000 solar luminosities. Internal genic energy production would rise only 6.5 fold to constitute a small percentage of the total. At this point the star would be in the process of being ripped apart both by Galactic core tidal forces and by its own elevated luminosity. For example this distance is within the 30 AU critical horizon within which a 40 solar radius star would become ripped apart. At a distance of 20 AU, the star would be traveling at 6.5% c (~20,000 km/s) with about 2 days until impact. The star's dense core of mass 0.1 solar masses would survive tidal forces and would continue intact to impact the core at about 92% of the speed of light. This would produce an energy release of ~2 X 1053 ergs, equivalent to the output of a hypernova. The danger is that this could trigger a prolonged Seyfert-like galactic core explosion and accompanying superwave.
If the companion body were instead a planet or even a red dwarf, say having a mass of 0.1 solar masses, it would also experience rapid expansion of its envelope due to cosmic ray heating and rising genic energy production and would fragment into a high velocity cloud of ionized gas approaching the core. In this case, however, the energy release would be more prolonged with a total energy of 1052 ergs or less spread over a period of some weeks or months. This would produce a prolonged rise in the energy output of Sgr A* by many orders of magnitude, but whether it would trigger a superwave is not easily known.
What we are about to experience in a few months may be thought of as a cosmic game of Galactic pinball. In fact, the game Black Hole shown below offers an appropriate representation. The pin ball would represent the companion star or planet entering into close proximity with the Galactic core. Based on differing directions and velocities of the pinball, acted upon by the paddles, differing outcomes result which are not easily predicted. In a similar fashion, due to our limited knowledge of the system inside the G2 cloud and the circumstances of how any companion might be stripped away, we don't know what the final outcome will really be.
P.S. I don't mind so much if a game refers to the Galactic core as a black hole. It is when intelligent astronomers use this term in a serious way that it becomes disturbing. Stephen Hawking, however is making progress. See the news posting on the Starburst Foundation website regarding Hawking's recent rejection of the black hole idea.
Previous postings on the G2 Cloud:
Reading resources on superwaves:
• Earth Under Fire
• Galactic Superwaves and their Impact on the Earth
• A galactic superwave hazard alert (Nexus Magazine, 2001, German Nexus, 2009)
• Galactic core explosions and the evolution of life (Anthropos, 1990)
• Earth Moon and Planets paper