COMMISSION 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 3828 Konkoly Observatory Budapest 15 January 1993 HU ISSN 0374 - 0676 PHOTOGRAPHIC OBSERVATIONS OF A NEWLY DISCOVERED INTERMEDIATE POLAR RE 0751+14 AND OF THE OBJECT OI 090.4 Mason et al. (1992) discovered a new intermediate polar in the ROSAT Wide. Field Camera All-Sky Survey. Its position is RA=7h51m17.3s, Dec=-14d44'23" (2000). We studied it on 24 archival plates obtained at the 40-cm astrograph on the Crimean Station of the Sternberg State Astronomical Institute (fields 12 Cnc and 3 Cnc). To make brightness estimates of comparison stars, we used the photoelectric sequence for OI 090.4 (Baumert, 1978). It is worthy to mention that the brightness values for stars a and b must be interchanged in this latter paper, as one may see from comparison with other stars with known photographic magnitudes. All plates were measured by using an iris-photometer of the Sternberg Stale Astronomical Institute. Brightness values for the comparison stars were determined from a parabolic fit by using the 12 best plates. They are listed in Table 1. The finding chart of RE 0751+14 is shown in Fig. 1. An identification chart for OI 090.4 can be found in Baumert's (1978) paper. For all plates, the parabolic fits were computed by using these values of brightness. Results are presented in Table 2 for RE 0751+14 as well as for the object OI 090.4. The amplitude of variability of OI 090.4 reached 1.3m (between 15.58m and 16.87m). Only minor brightness variations of RE 0751+14 between 13.65m and 14.17m were detected, as one may expect for usual `high' state of intermediate polars. A `low' state was not detected in the present material. The mean magnitude was 13.93m, a r.m.s. deviation from the mean value was 0.15m. A possible brightening of the comparison star p up to 13.47m was detected on JD 2447615.254 without any significant variations around usual brightness 14.56m at other dates. Star G and H have close visual companions, thus they were not used for fits, nor the star p. Table 1 Photographic brightness of comparison stars for RE 0751+14 * m_pg * m_pg * m_pg * m_pg a 13.34+-.02 g 13.98+-.03 n 14.45+-.02 t 14.77+-.03 b 13.44 .03 G 14.06 .07: p 14.45 .03 u 14.78 .01 c 13.54 .02 h 14.20 .02 H 14.56 .04: w 15.55 .02 d 13.59 .02 k 14.28 .02 q 14.68 .02 x 15.64 .02 e 13.64 .02 l 14.32 .02 r 14.71 .03 y 15.74 .02 f 13.77 .02 m 14.35 .02 s 14.72 .03 z 16.13 .03 [FIGURE 1] Figure 1. Finding chart for RE 0751+14 Table 2 Brightness of RE 0751+14 and OI 090.4 JD 24.... RE OI JD 24.... RE OI 45328.516 13.91 - 47883.480 13.90 16.20 45349.445 13.67 - 47884.544 13.86 16.20 45410.302 13.98 - 47887.528 13.90 15.84 47484.609 14.08 16.87 47890.469 14.05 - 47614.305 13.89 16.60 47896.347 13.85 15.87 47615.254 13.78 16.43 47916.406 13.65 15.76 47623.304 13.96 - 47918.406 13.68 15.71 47834.536 13.95 16.07 47922.354 14.17 15.60 47836.551 14.06 15.68 47941.337 13.99 15.58 47855.499 14.10 15.95 47943.284 14.05 15.74 47855.522 14.12 15.87 47944.345 14.02 15.68 47869.576 13.89 16.14 47946.287 13.70 16.02: IVAN L. ANDRONOV Department of Astronomy, Odessa State University, T.G. Shevchenko Park, Odessa 270014, Ukraine References: Baumert, J. H. 1978, Inform. Bull. Var. Stars No. 1410 Mason, K.O., Watson, M.G. Ponman T.J. Charles, P.A., Duck, S.R., Hassal, B.J.M., Howell, S.B., Ishida, M., Jones, D.H.P., Mittaz, J.P.D., 1992, Mon. Not. Roy. Astron. Soc. (in press)