  Within the framework of Extended Space Model (ESM) the processes connected to
birth of photons in a gravitational field are studied. These photons have a
nonzero mass. It can be both positive, and negative, and photon's energy and
strength of the gravitational field determine its absolute value. It is shown
that in ESM model formation of bubble gravitational structures is possible. In
the frame of ESM one can obtain the follow physical picture. Bubble
gravitational objects have a halo formed by dark matter generated by photons
with a positive mass. The photons with a negative mass are throw away in free
deep space and create there antigravitating vacuum with negative pressure. The
comparison ESM bubble structures with similar objects of a type "gravastar",
existing in a General Theory of Relativity (GR) is made.
