Kevin Heckle (2 March 2011)
"RE: M. Colunga's Brown Dwarf"

Dear Michael,
Being a Brown Dwarf makes it the perfect dark object for conspiracy theorists....or not.  Based on the distance you cited in the first article of being somewhere between 2 and 3 AU from earth, this object would be EXTREMELY visible with the NAKED EYE.  A telescope would be unnecessary.  The word ' brown' is not indicative of it's color, it is indicative of it's temperature.  A brown dwarf is like a fence rider.  It is to massive to be a planet, yet not massive enough to ignite fusion of its gases to become a star.  It is neither a planet or a star, but something in between.  Even so, it could emit some light of its own electromagnetically from the surface I suppose.   Large scopes have sighted one optically from 20 light years distance.  However, this object if it existed and was truly a brown dwarf within the distance you described, it would NOT NEED to emit its own light to be visible.  Its density would be greater than the GAS GIANT Jupiter which also does not emit its own light, but rather REFLECTS the light of the sun.  A brown dwarf made up of the same type of elements as Jupiter would be HIGHLY REFLECTIVE of the SUN'S LIGHT.  It would be so bright a blind man could see it.  Not really, but everyone else could.
IF you understood how many NASA engineers it takes to install ONE SCREW, you would quickly realize that any conspiracy originating behind NASA's doors could not be contained as there are too many loose lips in ANY orginization with several thousand people.  I'm not saying NASA knows it all, but if there was a Niburu they would tell it seeking billions from Congress to study it, send probes, etc.  What of the other space agencies in the world? Are they keeping the secret too? 
Kevin H.