COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 690 Konkoly Observatory Budapest 1972 June 27 PHOTOMETRIC OBSERVATIONS OF 13 CEPHEID VARIABLES In the years 1965-1968 photoelectric observations were made of 13 Cepheid variables. The observations were made with the 10-inch refractor telescope of the Leiden Observatory. The sensitivity of the photometer-filter-telescope system is close to the V-band of the U.B.V.-system. All observations were made with respect to a nearby comparison star. Table I lists the variables with their comparison stars. The observations are listed in Table II. The first column of Table II gives the time of observation of the variable in Heliocentric Julian Days. The second column gives the magnitude difference variable minus comparison star. Corrections for differential extinction were only applied if Delta sec z>0.01. In those cases a standard extinction coefficient was used. TABLE I Variables and Comparison Stars Variable Comparison Star BK Aur BD +49deg1310 RX Aur +39deg1157 SY Aur +42deg1192 RW Cam +58deg 672 RX Cam +58deg 708 SU Cas +67deg 224 W Gem +15deg1255 SV Mon + 6deg1215 AU Peg +17deg4591 AW Per +36deg 926 SV Per +42deg1067 SW Tau + 3deg 597 SZ Tau +17deg 750 TABLE II THE OBSERVATIONS BK Aur Hel. J.D. Delta m 2439053.582 +0.42 054.610 +0.29 056.534 -0.24 080.580 -0.23 081.545 -0.15 136.534 -0.23 204.605 +0.24 507.506 +0.10 536.408 -0.27 537.525 -0.14 587.450 +0.09 594.403 -0.18 RX Aur 2439026.627 -0.60 028.691 -0.95 031.525 -0.82 039.592 -0.77 052.601 -1.05 053.568 -0.93 054.564 -0.83 055.588 -0.74 056.518 -0.62 136.483 -0.86 205.517 -0.55 507.531 -0.85 537.313 -0.47 537.582 -0.50 543.473 -0.74 587.419 -1.02 802.492 -0.57 884.473 -0.36 SY Aur 2439053.642 +0.43 056.547 -0.17 080.562 +0.22 136.499 -0.41 507.545 +0.15 536.423 +0.18 537.537 +0.22 594.431 -0.15 RW Cam 2439005.547 +0.50 010.440 +0.59 018.403 +0.14 019.507 +0.27 024.469 +0.68 025.524 +0.70 026.525 +0.60 028.551 +0.47 031.490 -0.11 038.534 +0.50 039.489 +0.60 052.477 +0.28 053.433 +0.36 054.482 +0.47 059.507 +0.67 080.378 +0.06 081.412 -0.12 802.482 -0.10 803.459 -0.07 815.455 +0.54 RX Cam 2438984.576 +0.25 8991.516 +0.63 8996.588 +0.77 9005.526 +0.95 010.424 +0.36 018.387 +0.34 019.494 +0.64 024.449 +0.25 025.509 +0.43 026.513 +0.40 028.538 +0.80 031.473 +0.48 038.510 +0.83 039.476 +0.40 044.535 +0.86 052.453 +0.86 053.424 +0.98 054.471 +0.79 059.496 +0.72 080.361 +0.39 080.641 +0.44 081.561 +0.36 802.479 +0.60 803.449 +0.73 815.446 +0.26 884.413 +1.00 913.493 +0.66 SU Cas 2438977.574 -0.12 8984.511 +0.16 8985.462 -0.08 8991.468 -0.01 8996.568 -0.13 9005.484 +0.14 010.406 -0.20 018.355 -0.18 018.495 -0.12 019.471 +0.17 019.614 +0.12 024.432 -0.08 025.473 +0.16 025.602 +0.04 026.493 -0.01 028.525 +0.00 031.458 +0.05 031.504 -0.00 031.591 -0.09 038.489 +0.10 039.502 -0.12 044.520 +0.15 052.538 +0.18 053.412 -0.20 053.458 -0.18 802.395 +0.02 802.461 +0,04 803.371 +0.06 815.430 -0.20 884.387 +0.05 917.448 +0.01 W Gem 2439052.656 -0.63 053.620 -0.66 054.641 -0.39 056.607 -0.08 080.519 -0.04 136.443 -0.00 137.507 -0.28 139.524 -0.52 186.474 -0.76 205.458 -0.31 507.520 -0.11 527.472 -0.65 536.368 -0.67 537.552 -0.31 566.386 -0.78 587.403 +0.01 594.373 -0.13 913.459 -0.50 917.412 -0.37 SV Mon 2439052.640 -0.04 053.608 -0.21 080.496 -0.20 136.424 -0.80 137.493 -0.66 138.404 -0.59 139.447 -0.43 186.440 -0.30 205.430 -0.11 507.480 -0.15 550.360 -0.51 566.371 -0.41 587.371 -0.31 AU Peg 2439018.475 -0.15 019.447 -0.20 019.599 -0.30 022.509 -0.36 025.450 -0.25 026.456 -0.08 028.508 -0.07 030.486 -0.18 039.438 -0.36 039.513 -0.33 044.463 -0.29 051.496 -0.31 052.422 -0.05 052.496 -0.01 055.397 -0.38 053.474 -0.37 054.454 -0.18 056.440 -0.25 AW Per 2439028.654 -0.12 052.569 -0.44 053.546 -0.31 054.538 -0.10 055.562 -0.05 056.493 -0.52 077.490 -0.64 507.493 -0.05 536.381 -0.68 537.298 -0.47 537.568 -0.55 587.385 -0.80 594.358 -0.74 884.439 -0.83 917.428 -0.72 SV Per 2439026.604 +0.06 028.572 -0.14 031.538 -0.74 038.592 +0.08 039.573 -0.10 052.584 -0.28 053.556 -0.74 054.552 -0.58 055.575 -0.51 056.507 -0.40 077.507 -0.52 136.516 -0.11 210.318 -0.60 507.457 -0.17 536.391 -0.21 537.287 -0.05 543.458 -0.76 587.435 -0.58 884.451 +0.08 SW Tau 2439026.650 +0.10 028.622 -0.45 038.574 -0.54 052.536 -0.56 053.519 +0.09 054.517 -0.37 054.579 -0.26 055.537 -0.41 056.464 -0.11 056.567 -0.00 077.455 +0.14 079.417 -0.56 136.404 -0.57 139.471 -0.40 SZ Tau 2439025.574 +0.35 026.582 +0.17 028.593 +0.36 031.572 +0.32 038.545 +0.36 039.552 +0.05 052.552 +0.03 052.678 +0.05 053.533 +0.29 054.529 +0.37 054.594 +0.25 055.549 +0.04 056.479 +0.24 056.581 +0.26 077.474 +0.04 080.474 +0.08 081.526 +0.19 087.457 +0.08 139.502 +0.32 Sterrewacht Leiden WILLEM WAMSTEKER Lunar and Planetary Laboratory University of Arizona Tucson, Arizona