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View Full Version : Astronomers Doubt Giant Planet 'Tyche' Exists in Our Solar System



Radojica
02-17-2011, 12:37 PM
A duo of planetary astronomers has grabbed media attention by claiming a planet four times the size of Jupiter (http://www.lifeslittlemysteries.com/how-big-is-jupiter-0422/) may be lurking in the outer solar system (http://www.space.com/4795-enduring-mysteries-outer-solar-system.html). They call the planet Tyche.

Many astronomers, however, say it probably isn't there.
The claim, by John Matese and Daniel Whitmire of the University of Lousiana-Lafayette, is not new: They have been making a case for Tyche since 1999, suggesting that the giant planet's presence (http://www.lifeslittlemysteries.com/what-types-of-alien-planets-are-out-there-1241/) in a far-flung region of the solar system (http://www.lifeslittlemysteries.com/how-was-the-solar-system-formed-1038/) called the Oort cloud would explain the unusual orbital paths of some comets that originate there.


"There's evidence that some Oort cloud comets (http://www.lifeslittlemysteries.com/asteroid-comet-or-meteor-1139/) display orbital peculiarities," Matese told Life's Little Mysteries. "We're saying that perhaps the pattern is indicative that there's a planet there."
Although their argument is similar to the one they originally made, "what's new is that this pattern has persisted," Matese said. "It's possible that it's a statistical fluke, but that likelihood has lessened as more data has accumulated in the past 10 years."
Matese says NASA's WISE telescope may have already collected infrared data from Tyche that would be hard to pick out from within the telescope's immense database. "The spectrum we have predicted is uncertain, and there may be a great many signals that are similar to what are expected for our object. So this may take time," he said. A signal from Tyche--if it's there--could be located within two years, he said.
Not everyone is as optimistic.
Required: 'Incredible proof'
Matthew Holman, a planetary scientist at the Harvard Smithsonian Institute of Astrophysics, is not a Tyche believer. Though he hasn't read the latest version of Matese's and Whitmire's argument, Holman told Life's Little Mysteries, "Based on past papers that I've seen looking at where long-period comets came from in the sky, and finding signatures of large perturbers of the Oort cloud, I was not persuaded by the evidence."
Hal Levison, a planetary scientist at the Southwest Research Institute in Boulder, Colo., who recently authored a paper on the Oort cloud for the journal Science, seconded that opinion.
"I haven't read this version of his paper, which he claims now has better statistics than the previous attempts, where he also claimed that he saw evidence of this object," Levison said. "But in previous papers, I really think he did his statistics wrong. Incredible claims require incredible proof and I really believe that he doesn't understand how to do this statistical analysis correctly."
"What Matese claims is that he sees an excess of comets coming from a particular place, which he attributes to the gravitational effects of a large planet in the Oort cloud. I have nothing against the idea, but I think the signal that he claims he sees is very subtle, and I'm not sure it's statistically significant," Levison told Life's Little Mysteries.
"There's another group in England that claims the same thing, but with Jupiter on the other side of the sun," Levison said. "And they also claim to explain the excess of comets."
As always, it's difficult to prove or disprove anything that you can't see or touch, but for now, considering that most astronomers aren't even sure that such an excess of comets exists in the first place, it may be too early to get psyched about Tyche.

link
(http://www.lifeslittlemysteries.com/mystery-planet-tyche-probably-not-there-1356/)

Cato
02-17-2011, 05:58 PM
A planet four times the size of Jupiter would create very noticeable gravitational anomalies in the outer solar system and Oort Cloud.

I call foul on this one, unless it's proven to be a planet or some substellar object like a brown dwarf.

Loddfafner
02-17-2011, 06:05 PM
Given that there is a 26 million year cycle for mass extinctions, there might be something massive out there with an eccentric orbit of that length that throws major asteroids at the inner solar system.

Radojica
02-17-2011, 11:19 PM
A planet four times the size of Jupiter would create very noticeable gravitational anomalies in the outer solar system and Oort Cloud.

That's how these two astronomers think there's some huge planet. Long term comets are behaving like there's something which is sending them toward the Sun.


I call foul on this one, unless it's proven to be a planet or some substellar object like a brown dwarf.

Agree, although those two astronomers said they are expecting tin the next two years to present evidences for this new planet.


Given that there is a 26 million year cycle for mass extinctions, there might be something massive out there with an eccentric orbit of that length that throws major asteroids at the inner solar system.

I've read that revolution of this planet is approximately 18 million years (if it exist at all), so in astronomical terms it's quite close.

Cato
02-18-2011, 12:49 PM
That's how these two astronomers think there's some huge planet. Long term comets are behaving like there's something which is sending them toward the Sun.


Well, I'm thinking more in terms of something that big having, say, multiple satellites like the gas giants. Cometary trajectory being affected, hmm, a case of gravity antipodes.

I wouldn't call it a planet; how could something that huge form in the outer fringes of the solar system when most of the solid stellar mass is found in the inner solar system? If something that huge is out there, it has to be, say, a burn-out star or somesuch.

Loddfafner
02-18-2011, 01:40 PM
Nemesis (http://en.wikipedia.org/wiki/Nemesis_%28star%29) is what I was thinking of:


Nemesis is a hypothetical hard-to-see red dwarf star,[1] white dwarf star[2] or brown dwarf,[3] orbiting the Sun at a distance of about 50,000 to 100,000 AU (about 0.8-1.5 light-years), somewhat beyond the Oort cloud.[4] This star was originally postulated to exist as part of a hypothesis to explain a perceived cycle of mass extinctions in the geological record, which seem to occur once every 27 million years or so. In addition, observations by astronomers of the sharp edges of Oort clouds, similar to that of the Solar System, around various binary (double) star systems, in contrast to the diffuse edges of the Oort clouds around single-star systems, has prompted some scientists to postulate that a dwarf star may be co-orbiting the Sun.[4]

Cato
02-18-2011, 01:50 PM
Nemesis, I haven't heard of that one, but it seems to be a more well-developed explanation for what my original contention was: that any large body in the Oort Cloud would have to be a brown dwarf or other similar stellar object.

Radojica
02-19-2011, 12:19 AM
Nemesis (http://en.wikipedia.org/wiki/Nemesis_%28star%29) is what I was thinking of:

Hmm, I was thinking about the same thing too, what's more, I was thinking about that tonight while I was walking home from work...


Nemesis, I haven't heard of that one, but it seems to be a more well-developed explanation for what my original contention was: that any large body in the Oort Cloud would have to be a brown dwarf or other similar stellar object.

I am probably too stupid about whole thing, but, then again, I am asking myself, how is it possible that by now nobody detected any kind of radiation in our close vicinity, yet we (humans) are able to detect from object billions of years in our past :shrug:?

Cato
02-19-2011, 02:52 AM
I am probably too stupid about whole thing, but, then again, I am asking myself, how is it possible that by now nobody detected any kind of radiation in our close vicinity, yet we (humans) are able to detect from object billions of years in our past :shrug:?

Because our instruments haven't been looking for such an object? And don't forget that such a hypothetical object wouldn't have the spectral or radioactive emissions of a main sequence star like the sun. :)

Svipdag
02-19-2011, 03:16 AM
It seems to me that the mass of Tyche would be too LOW for it to be a red dwarf star. However, the hypothesis that it is a gas giant like those within the Oort Belt encounters problems.

There is too much matter in the Oort Belt for it to be left over from the formation of a single gas giant star. Yet, if planetogenesis can take place in the Oort Belt, why would there be but one gas giant where there is ample material to have formed several ?

The best evidence for the existence of a large body in the Oort Belt would be occultation of a star by it. Unfortunately, failiure to observe such an occultation does not DISprove the existence of Tyche, it proves nothing.