Why the heck would you use "google images" to search for astronomical images of brown dwarf stars? They do exist, even in visible light, as I pointed out above. You also have the additional factor of the sun's light reflecting off the dwarf that you must take into account. For a brown dwarf at the distance Elenin is currently at this would make it not only visible, but incredibly bright compared to the stars.

For the rest of the nonsense you'll find these articles incredibly enlightening:

Unidentified point sources in the IRAS minisurvey, Houck et al. Astrophysical Journal, vol. 278, March 1, 1984, p. L63-L66

Unidentified IRAS sources - Ultrahigh-luminosity galaxies, Houck et al., Astrophysical Journal, vol. 290, March 1, 1985, p. L5-L8.

Optical counterparts of unidentified IRAS point sources Infrared luminous galaxies, Aaronson and Olszewski, Nature, vol. 309, May 31, 1984, p. 414-417.

Planet X - No dynamical evidence in the optical observations, Standish, E. M. Astronomical Journal (ISSN 0004-6256), vol. 105, no. 5, p. 2000-2006.