  The central 0.1 parsecs of the Milky Way host a supermassive black hole
identified with the position of the radio and infrared source Sagittarius A*, a
cluster of young, massive stars (the S stars) and various gaseous features.
Recently, two unusual objects have been found to be closely orbiting
Sagittarius A*: the so-called G sources, G1 and G2. These objects are
unresolved (having a size of the order of 100 astronomical units, except at
periapse, where the tidal interaction with the black hole stretches them along
the orbit) and they show both thermal dust emission and line emission from
ionized gas. G1 and G2 have generated attention because they appear to be
tidally interacting with the supermassive Galactic black hole, possibly
enhancing its accretion activity. No broad consensus has yet been reached
concerning their nature: the G objects show the characteristics of gas and dust
clouds but display the dynamical properties of stellar-mass objects. Here we
report observations of four additional G objects, all lying within 0.04 parsecs
of the black hole and forming a class that is probably unique to this
environment. The widely varying orbits derived for the six G objects
demonstrate that they were commonly but separately formed.
