  Millimeter observations of the galactic source of relativistic ejections GRS
1915+105 (Mirabel & Rodriguez 1994) are consistent with this source being at a
kinematic distance D = 12.5 +/- 1.5 kpc from the Sun, behind the core of a
molecular cloud at 9.4 +/- 0.2 kpc. At this distance, GRS 1915+105, frequently
radiating nearly 3 x 10^{38} erg/s in the X-rays, becomes the most luminous
X-ray source in the Galaxy. The total hydrogen column density Nh = 4.7 +/- 0.2
x 10^{22} cm-2 along the line of sight corresponds to a visual absorption Av =
26.5 +/- 1 magnitude.
  The infrared counterpart of GRS 1915+105 exhibits in the 1.2 micrometre - 2.2
micrometre band variations of nearly 1 magnitude in a few hours and of nearly 2
magnitudes over longer intervals of time. In the infrared, GRS 1915+105 is
strikingly similar to SS 433, and unlike any other known stellar source in the
Galaxy. The infrared resemblance in absolute magnitude, color, and time
variability, between these two sources of relativistic ejections suggests that
GRS 1915+105, as SS 433, consists of a collapsed object (neutron star or black
hole) with a thick accretion disk in a high-mass-luminous binary system.
