Compact radio sources in the vicinity of the ultracompact HII region
  G78.4+2.6
  Using the Very Large Array (VLA) at 3.6~cm we identify four new compact radio
sources in the vicinity of the cometary HII region G78.4+2.6 (VLA~1). The four
compact radio sources (named VLA~2 to VLA~5), have near-infrared counterparts,
as seen in the 3.6 $\mu$m Spitzer image. One of them (VLA~5) clearly shows
evidence of radio variability in a timescale of hours. We explore the
possibility that these radio sources are associated with pre-main sequence
(PMS) stars in the vicinity of the UC HII region G78.4+2.6. Our results favor
the smaller distance value of 1.7 kpc for G78.4+2.6. In addition to the
detection of the radio sources in the vicinity of G78.4+2.6, we detected
another group of five sources which appear located about 3' to the northwest of
the HII region. Some of them exhibit extended emission.
