  Multiple near-infrared wavelengths observations, carried out since 1993 on
the galactic superluminal source of relativistic ejections GRS 1915+105, have
yielded three important results. 1) The infrared counterpart of GRS 1915+105
exhibits various variations in the 1.2 - 2.2 micrometer band: the strongest are
of nearly 1 magnitude in a few hours and of nearly 2 magnitudes over longer
intervals of time. 2) The infrared properties of GRS 1915+105 are strikingly
similar to those of SS 433, and unlike those of any other known stellar source
in the Galaxy. The absolute magnitudes, colors, and time variabilities of these
two sources of relativistic ejections suggest that GRS 1915+105, like SS 433,
consists of a collapsed object (neutron star or black hole) with a thick
accretion disk in a high-mass-luminous binary system. 3) During an intense and
long-term X-ray outburst of GRS 1915+105 in 1995 August, where a pair of
radio-emitting clouds emerged from the compact core in opposite directions at
relativistic speeds, we observed the time-delayed reverberation of this radio
flare/ejection event in the infrared wavelengths. The observed spectrum of the
enhanced infrared emission suggests the appearance of a warm dust component.
