  Here we draw attention to a candidate system with one hot Jupiter and one
small, nearby companion, revealed by the recent Kepler data release (DR25). The
hot Jupiter, Kepler-730b, has radius $R_{\rm p}=11.36^{+1.14}_{-0.98}~R_\oplus$
and orbital period $P=6.492$ d, and the newly discovered companion, KOI-929.02,
has $R_{\rm p}=1.45^{+0.15}_{-0.20}~R_\oplus$ and $P=2.852$ d. No transit
timing variation (TTV) was detected because of the marginal detection of the
small companion transit, but this small companion passed all the validation
tests. This system is probably another planetary system with hot Jupiter and
small, nearby companion, after the outstanding WASP-47 system, and so far the
only such system (out of 46) in the prime Kepler mission. The nature of this
system, if confirmed, would suggest that hot Jupiters with small, nearby
companions are probably more common than we used to believe. There remains a
possibility that the small companion actually transits a star that is different
from the hot Jupiter host, and follow-up observations with 10-m telescopes can
potentially resolve this issue.
