IAU COMMISSION 27 UNPUBLISHED DATA FILE 307E Differential V-band Photometry of V777 Tau and HD 23375 Observers: Kevin Krisciunas, Richard Crowe, Mavourneen Roberts Site: University of Hawaii 0.6-m telescope, Mauna Kea, Hawaii Inclusive dates: 3 Sep to 23 Oct 1995 (UT) S. Horan (1979, Astron J., 84, 1770) found 71 Tau (= BS 1394 = HD 28052 = V777 Tau) to be a delta Scuti star with a principal period of 3.9 hours. We present new V-band photometry that allows us to investigate its level of variability and its period(s). The data were obtained on 5 nights from 17 Oct to 23 Oct 1995 UT and amount to 58 points obtained differentially with respect to BS 1422. BS 1432 served as the check star. M. Breger (1972, ApJ, 176, 367) found HD 23375 in the Pleiades to be variable by 0.01 mag in V on a time scale longer than one would expect for delta Scuti stars. It is a gamma Doradus-type variable star candidate (Krisciunas and Handler, 1995, IBVS 4195). We present V-band photometry with respect to Tr 121, using Tr 688 as the check star. The data were obtained on 7 nights from 3 Sep to 22 Oct 1995 UT and amount to 44 points on each star. We find no evidence for variability. Column 1 = heliocentric Julian Date [245 0000 + ...] Column 2 = delta V magnitude Kevin Krisciunas Joint Astronomy Centre 660 N. A'ohoku Place Hilo Hawaii 96720 USA ******************************************************************************* 71 Tau vs. BS 1422 8.0326 -1.0756 8.0373 -1.0781 8.0422 -1.0780 8.0482 -1.0759 8.0818 -1.0853 8.0860 -1.0877 8.0905 -1.0867 8.0952 -1.0860 8.1003 -1.0842 10.9367 -1.0698 10.9413 -1.0742 10.9456 -1.0770 10.9501 -1.0783 11.0327 -1.0819 11.0375 -1.0792 11.0413 -1.0788 11.0464 -1.0771 11.0763 -1.0757 11.0807 -1.0662 11.0846 -1.0714 11.0886 -1.0769 11.0950 -1.0701 11.0993 -1.0767 11.1032 -1.0814 11.1082 -1.0820 12.0534 -1.0845 12.0577 -1.0840 12.0619 -1.0823 12.0660 -1.0796 12.0698 -1.0835 12.0742 -1.0860 12.0785 -1.0863 12.0840 -1.0841 12.0874 -1.0808 13.0305 -1.0908 <-- this point is a bit off (don't know quite why) 13.0343 -1.0751 13.0378 -1.0776 13.0414 -1.0756 13.0446 -1.0832 13.0499 -1.0802 13.0545 -1.0753 13.0587 -1.0746 13.1005 -1.0779 13.1039 -1.0744 13.1080 -1.0775 13.1121 -1.0803 13.1159 -1.0727 13.1195 -1.0730 13.1230 -1.0716 14.0337 -1.0720 14.0384 -1.0710 14.0431 -1.0752 14.0485 -1.0776 14.0531 -1.0783 14.0582 -1.0776 14.0627 -1.0763 14.0669 -1.0776 14.0721 -1.0812 BS 1432 vs. BS 1422 8.0344 0.4361 8.0389 0.4384 8.0446 0.4415 8.0496 0.4435 8.0834 0.4358 8.0873 0.4374 8.0919 0.4352 8.0971 0.4383 8.1015 0.4379 10.9384 0.4378 10.9427 0.4440 10.9472 0.4399 10.9515 0.4378 11.0342 0.4380 11.0386 0.4410 11.0430 0.4419 11.0476 0.4418 11.0776 0.4414 11.0820 0.4445 11.0858 0.4413 11.0905 0.4454 11.0964 0.4431 11.1005 0.4406 11.1044 0.4284 11.1096 0.4336 12.0551 0.4385 12.0590 0.4424 12.0631 0.4465 12.0672 0.4461 12.0709 0.4436 12.0757 0.4412 12.0816 0.4342 12.0852 0.4407 12.0885 0.4388 13.0317 0.4408 13.0356 0.4390 13.0391 0.4469 13.0424 0.4434 13.0458 0.4359 13.0514 0.4429 13.0559 0.4425 13.0601 0.4397 13.1016 0.4407 13.1050 0.4377 13.1095 0.4341 13.1135 0.4374 13.1171 0.4374 13.1206 0.4431 13.1241 0.4428 14.0352 0.4440 14.0399 0.4402 14.0447 0.4415 14.0501 0.4392 14.0550 0.4390 14.0597 0.4417 14.0641 0.4418 14.0685 0.4387 14.0736 0.4433 Note that for these stars in the Pleiades the heliocentric Julian Dates are referenced to 244 9000, not to 245 0000. HD 23375 vs Tr 121 delta V, 3-5 Sep, 17, 20-22 Oct 1995 UT 964.0212 0.4581 964.0287 0.4619 964.0341 0.4587 964.0416 0.4569 964.0480 0.4513 964.0530 0.4608 964.0582 0.4548 964.0627 0.4576 964.9684 0.4545 964.9728 0.4489 964.9773 0.4533 964.9814 0.4550 964.9855 0.4526 964.9900 0.4608 964.9942 0.4532 964.9985 0.4547 965.9664 0.4552 965.9705 0.4493 965.9745 0.4546 965.9794 0.4525 965.9839 0.4568 965.9878 0.4535 965.9924 0.4547 965.9961 0.4531 1008.0589 0.4585 1008.0650 0.4621 1008.0699 0.4532 1008.0746 0.4545 1011.0558 0.4522 1011.0606 0.4563 1011.0651 0.4544 1011.0695 0.4509 1012.0323 0.4760 <-- this point is too faint owing to a somewhat high first reading on the comp star (that is to say, we had a slight change in zero point which was not taken care of by linear interpolation of the comparison star measures) 1012.0371 0.4567 1012.0416 0.4484 1012.0457 0.4530 1013.0670 0.4598 1013.0712 0.4543 1013.0750 0.4547 1013.0788 0.4534 1013.0833 0.4472 1013.0869 0.4566 1013.0907 0.4521 1013.0944 0.4570 Tr 688 vs. Tr 122 delta V, 3-5 Sep, 17, 20-22 Oct 1995 UT 964.0240 -0.6488 964.0304 -0.6401 964.0374 -0.6389 964.0449 -0.6409 964.0498 -0.6382 964.0553 -0.6391 964.0598 -0.6426 964.0643 -0.6333 964.9699 -0.6398 964.9741 -0.6400 964.9786 -0.6361 964.9828 -0.6383 964.9867 -0.6363 964.9915 -0.6355 964.9957 -0.6372 965.0002 -0.6386 965.9678 -0.6386 965.9719 -0.6376 965.9762 -0.6375 965.9810 -0.6412 965.9853 -0.6433 965.9891 -0.6403 965.9936 -0.6418 965.9974 -0.6391 1008.0614 -0.6452 1008.0667 -0.6466 1008.0715 -0.6388 1008.0760 -0.6426 1011.0576 -0.6372 1011.0621 -0.6377 1011.0665 -0.6406 1011.0714 -0.6387 1012.0344 -0.6336 <-- this point seems OK though the first comp star measure was a bit off (see note above) 1012.0385 -0.6443 1012.0431 -0.6445 1012.0468 -0.6395 1013.0686 -0.6310 1013.0725 -0.6394 1013.0763 -0.6405 1013.0801 -0.6410 1013.0844 -0.6430 1013.0882 -0.6394 1013.0920 -0.6431 1013.0958 -0.6454