COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 1557 Konkoly Observatory Budapest 1979 February 23 UBV OBSERVATIONS OF RR Lyr A series of UBV observations of RR Lyr was made, beginning just before maximum brightness, on August 31, 1978. The twin telescope of the Shemakha station of the Zentralinstitut fur Astrophysik (see Hildebrandt, Panov, 1975) was used. The comparison star was HD 182487. The results are shown in Table I. The observed magnitude differences were transformed to the UBV system with the help of UBV magnitudes for HD 182487 given by Preston et al. (1965) and transformation coefficients obtained from observations of ten standard stars. With each magnitude its quadratic error and the number of observations N is given. The V maximum (7.20 mag) is at JD (hel.)=2443752.205. No indications of short time brightness fluctuations have been found. W. SCHONEICH and D. LANGE Zentralinstitut fur Astrophysik Astrophysikalisches Observatorium Potsdam, GDR 15 Potsdam, Telegraphenberg References: Hildebrandt,G., Panov, K., (1975) IAU Coll. No. 29, Budapest, p. 85, Vol. 2 [BIBCODE 1976mpvs.conf...85H ] Preston, G.W., Smak, J., Paczynski, B., (1965) Ap.J.Suppl. XII, 99 [BIBCODE 1965ApJS...12...99P ] Table I UBV Magnitudes for RR Lyr ------------------------------------------------------------------------ JD (hel.) V N B N U N 2443752+ ------------------------------------------------------------------------ .197 7.206 0.003 5 7.391 0.005 5 7.524 0.005 5 .202 7.198 0.002 5 7.375 0.003 5 7.525 0.006 5 .205 7.198 0.003 5 7.376 0.002 5 7.531 0.006 5 .209 7.195 0.007 5 7.376 0.002 5 7.548 0.007 5 .213 7.211 0.004 5 7.387 0.003 5 7.548 0.006 5 .220 7.241 0.003 5 7.424 0.003 5 7.586 0.004 5 .224 7.253 0.005 5 7.446 0.003 5 7.613 0.005 5 .228 7.275 0.003 5 7.469 0.003 5 7.633 0.005 5 .232 7.292 0.005 5 7.491 0.003 5 7.653 0.006 5 .235 7.312 0.004 5 7.517 0.006 5 7.666 0.006 5 .243 7.345 0.002 5 7.567 0.005 5 7.718 0.006 5 .247 7.357 0.004 5 7.588 0.003 5 7.736 0.005 5 .251 7.384 0.002 5 7.607 0.012 4 7.748 0.012 5 .254 7.395 0.004 5 7.637 0.003 4 7.768 0.004 5 .258 7.418 0.004 5 7.657 0.002 3 7.797 0.004 5 .278 7.485 0.004 5 7.753 0.003 5 7.881 0.007 3 .281 7.500 0.002 5 7.774 0.003 5 7.900 0.007 3 .284 7.514 0.003 5 7.795 0.004 5 7.913 0.007 3 .288 7.531 0.002 5 7.811 0.003 5 7.928 0.007 5 .291 7.541 0.004 5 7.829 0.002 5 7.951 0.004 2 .300 7.562 0.005 5 7.860 0.004 5 7.976 0.002 3 .303 7.571 0.003 5 7.872 0.004 5 7.970 0.002 2 .307 7.583 0.003 5 7.890 0.003 5 7.995 0.005 3 .310 7.600 0.002 5 7.909 0.003 5 8.009 0.005 5 .314 7.607 0.003 5 7.923 0.004 5 8.023 0.003 5 ------------------------------------------------------------------------