We present molecular line observations of the star-forming cloud around RNO 6 along with a newly discovered nearby molecular cloud that we name RNO 6 NW .
Both clouds display striking similarities in their cometary structures and overall kinematics .
By using ^ { 13 } CO line observations , we estimate that these clouds have similar sizes ( \sim 4.5 pc ) and masses ( \sim 200 M _ { \sun } ) . Both molecular clouds RNO 6 and RNO 6 NW are active in star formation .
From new high resolution near-IR narrowband images , we confirm that RNO 6 hosts an embedded IR cluster that includes a Herbig Be star .
A conspicuous H _ { 2 } filament is found to delineate the dense cometary head of the globule .
RNO 6 NW hosts at least two IR sources and a bipolar molecular outflow of \sim 0.9 pc of length and \sim 0.5 M _ { \sun } of mass . We show that the cometary structure of both clouds has been created by the UV radiation from numerous OB stars lying \sim 1.5 ^ { \circ } to the north .
Such OB stars are associated with the double cluster h and \chi Persei , and are probably members of the Per OB1 association .
Thus star formation inside these clouds has been very likely triggered by the Radiation Driven Implosion ( RDI ) mechanism .
From comparison to RDI theoretical models , we find that the similar kinematics and morphology of both clouds is well explained if they are at a re-expansion phase .
Triggered sequential star formation also explains the observed spatial distribution of the members of the near-IR cluster inside the RNO 6 cloud , and the morphology of the H _ { 2 } filament .
We conclude that the RNO 6 and RNO 6 NW clouds are high-mass counterparts to the cometary globules of smaller masses which have been studied up to now .
Thus our observations demonstrate that the RDI mechanism can produce , not only low mass stars in small globules , but also intermediate mass stars and clusters in massive clouds .