Title: Some characteristics of the young open cluster Trumpler 37.
Abstract: New MK classifications (51 stars) and UBV magnitudes (37 stars) are presented for stars in the region of the cluster Trumpler 37, which is the nucleus of the association I Cephei (Cep OB 2). These are com bined with additional UBV magnitudes from Simonson (1968) and compared with the H-R diagram of upper Scorpius to derive a distance modulus of . The relationship of the supergiant Cep to the rest of the association is discussed and an absolute magnitude of -7.7 is derived if it is assumed to be a member. Key words: UBV photometry - MK spectral classification - clusters - associations