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Does Famous Exoplanet 'Fomalhaut b' Really Exist?
astroengine writes "The first exoplanet ever to be directly imaged by the Hubble space telescope may not exist. In 2008, the world was in awe of the famous 'Eye of Sauron' image of the star Fomalhaut's dusty ring — plus a slowly moving object that was identified as Fomalhaut b, a gas giant world approximately three times the mass of Jupiter. However, due to a strange orbital misstep detected between 2008 and 2009 photographs, the validity of Fomalhaut b's detection is being questioned, generating some controversy in the exoplanet community."
First Pluto, now Fomalhaut b. Before long we'll find the Earth isn't really a planet either. (Maybe a gigantic computer run by mice or something).
The further out the planet, and the bigger the star all factor into increasing the orbit time, so considering this planet is 3x the size of our biggest one (Jupiter) and that has an orbit of about 11 years (the size of Jupiter has nothing to do w/ orbit mostly), it might be a while before we can confirm this, possibly even a century.
According to TFA, the central problem is that the claimed planet seems to have an orbit which goes into the dusk disk around the star. But if this happens regularly, the disk should have been disrupted. The planet is also much brighter than one would expect for a planet in that position. If this isn't a planet it isn't clear what it is. There does seem to be something there. This could be some sort of artifact of the imaging methods but given the fact that it has been imaged with multiple instruments this seems extremely unlikely. So if this turns out not to be a planet we may be looking at some neat astronomical phenomenon not previously seen. Or it could be a bunch of unusually shiny dust. Hard to tell at this point. This is the sort of thing where the James Webb Telescope could be quite helpful. As of the last update it looks like James Webb is back on. But given how the current Congress acts, it could easily move to being canceled again.
This article seems to be about a grudge match between Paul Kalas, who was the lead in the discovery of this planet and Ray Jayawardhana, another astronomer who seems to want to be the first to have directly imaged an exoplanet. Since Kalas came first, Jayawardhana's only option seems to be to discredit the earlier discovery. One of his arguments is that Fomalhaut B wasn't really directly imaged since it probably has rings (accounting for its brightness) and so the rings were what was imaged and not the planet. The chief argument seems to be that the third picture taken of it doesn't match the expected orbit from the previous 2 pictures. The previous 2 pictures, however, were taken with an instrument that broke before the third picture was taken, so the accuracy of the third picture is in doubt. In any case, no-one seems to be doubting that it's something really, really big, but nowhere near big enough to be a star, that's been imaged in another star system. So, if it's not an exoplanet, it's still something extraordinary.
You lose! For exoplanets of mass insignificant compared to its parent star, the relation is
M(star) x Period^2 = Distance^3
So if the mass of the star were doubled, the period would decrease by a factor of 0.7071. And if the orbital radius doubled, the period would increase by a factor of 2.828.
On the plus side, that would alleviate the global warming situation, although to a degree of compensation much to our detriment.
"I guess the moral of the story is, don't paint your airship with rocket fuel." -- Addison Bain