[ngcles]

Hi Astro 78 & All,

Legitimate questions mate and I will attempt to answer, but my answers are partly speculative as you will see because they depend on what these miscreant believers have informed the world of the characteristics of this so called "object". Believe me, they are as silly as a duck and there is not one shred of evidence to support the claim.

This object does not exist at all except in the minds of those that "believe". I do not for one moment believe it exists.

But, of those that believe, this object is said to be in orbit around the Sun and the orbit is supposed to be 4000 years long (ie it returns to the inner solar-system every 4000 years). If it is in orbit, by definition it cannot be travelling faster than escape velocity (like say the Voyager and Pioneer space probes that are on non-return trajectories away into interstellar spece).

On the basis that it is in orbit it can't realistically be any further away than about Saturn's orbit on the way in.

"Nibiru" often claimed to be a "brown dwarf" or a "failed star". This would put its mass aproximately between 13 and 75 Jupiter masses. However it is often also said that it weighs in at about 4 to 8 Jupiter masses, meaning it is really only a big planet and not a brown dwarf -- as I understand the way Astronomers classify these things.

Irrespective, on the balance, an object of this sort that ordinarily dwells in the far outer solar-system would very likely have a composition and structure similar to Jupiter sized planets ie a mixture of Hydrogen & Helium in gasseous and liquid layers with perhaps a small silicate core.

For an object say, 4-8 Jupiter masses and of similar structure and composition, it would still be approximately the same size as Jupiter (maybe a fraction smaller actually) -- only much denser. Proceeding on these reasonable assumptions (they can only be assumptions because the object actually does not exist at all as I said) it would probably have reasonably similar properties to Jupiter in terms of Albeido (ability to reflect light) and also emit radio and infrared radiation like Jupiter.

Jupiter, at 5 Astronomical Units is ordinarily about visual magnitude -2.2 in our sky here on Earth. It is the 4th brightest object after the Sun, Moon and Venus. If this thing were even 3x further away than Jupiter (ie 15AU -- between Saturn & Uranus) (closer to Uranus actually) it would be about 1/9th as bright as Jupiter putting it at approx 1st magnitude. Because Jupiter is both Infrared and Radio bright as a result of its hot, churning, metallic hydrogen core (Jupiter is the brightest radio object in the night sky) it would stick out like carrot in an omlette to astronomers (amateur and professional) all round the world now. The fact it hasn't been "found" proves it isn't there at all and certainly won't be swinging past in 2012.

Even if it were 100AU out, it would still be very radio bright and would have been detected years and years ago.

No doubt people will now start some silly explaination, like it is made of anti-matter or something that doesn't reflect or emit radiation -- that why we can't see it. Even if this were so, the gravitational effects on the outer planets and KBOs would give it it away pretty quickly.

Hope this helps. Beyond this, I can really only get sarcastic about it.


Best,

Les D