COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 993 Konkoly Observatory Budapest 1975 April 28 HD 163868, A NEW BRIGHT SOUTHERN VARIABLE In his study of the light curve of V453 Sco, Gaposchkin (1938) used HD 163868 as one of several comparison stars. The present author observed V453 Sco at Cerro Tololo in 1974 using HD 163868 as a check star. Comparison with HD 163274, which Woodward and Koch (1975) show to be constant in light, clearly shows HD 163868 to be variable. The yellow and blue observations, on the natural instrumental system, are presented in Tables Ia and Ib, each observation being an 8-sec. integration with a 1P21 photometer on the Yale 1-m or the Lowell 61-cm reflectors. Only a few violet observations were obtained and these are not listed. The differential yellow and blue light and colourcurves are shown in the figure. It is apparent that the new [FIGURE 1] Differential light and colour curves for HD 163868 variable is reddest when it is brightest. If the variation is periodic, a lower limit of 20 days is indicated, but there is also a possibility of light variation on the time scale of several hours. On two nights HD 163868 was standardized using 7 stars from the Cousins, Lake, Stoy (1966) list. The V amplitude is at least 0m.18. B-V ranges from +0.02 to -0.04, and the average U-B is -0.73. A standard reddening law suggests HD 163868 to be a B1 V, B2 III or B4 Ia object. The spectral type of the star is B5 Ve, so that there is a small discrepancy between the spectrographic and photometric parameters. This could be due to the line emission. Until more observations are obtained, conjecture about the mechanism of variation is premature. I am grateful to CTIO for telescope time and for excellent help from several night assistants. EDITH JONES WOODWARD William Paterson College, Wayne,New Jersey, U.S.A. References: Cousins, A.W.J., Lake, R., and Stoy, R.H. (1966) Royal Obs. Bull 121, E3-55. [BIBCODE 1966RGOB..121....1C ] Gaposchkin, S. (1938) Harvard Bull, 909, 20. [BIBCODE 1938BHarO.909...20G ] Woodward, E.J., and Koch, R.H. (1975) (in press). TABLE Ia. Yellow observations of HD 163868 JD(hel.) V-C JD(hel.) V-C JD(hel.) V-C JD(hel.) V-C JD(hel.) V-C 2442000+ 2442000+ 2442000+ 2442000+ 2442000+ 208.5856 +.735 211.7248 +.571 212.6074 +.606 213.8005 +.577 219.7554 +.591 209.6077 .688 .7288 .562 .6311 .577 .8326 .582 .7565 .598 209.9052 .674 .7347 .559 .6774 .594 .8366 .601 .7579 .604 210.5474 .623 .7545 .562 .7157 .593 213.8690 .595 .7580 .597 .5612 .624 .7741 .568 .7462 .611 215.8358 .548 .8023 .594 .6064 .629 .7984 .567 .7589 .612 .8360 .548 .8024 .590 .6647 .625 .8173 .562 .7810 .617 215.8378 .555 .8232 .595 .7425 .610 .8233 .568 .7976 .622 216.6811 .569 .8233 .605 .7897 .611 .8300 .569 .8302 .606 .6813 .566 .8750 .593 .8238 .621 .8512 .572 .8346 .610 .7098 .622 219.8751 .590 .8373 .628 .8540 .568 .8622 .600 216.7100 .616 229.5413 .609 .8460 .626 .8692 .565 .8664 .603 218.5551 .570 .5414 .602 .8946 .638 .8734 .574 .8943 .598 .5553 .577 .8630 .621 .9036 .633 .8793 .560 212.9275 .595 .5556 .571 220.8636 .621 .9151 .630 .8972 .570 213.5268 .553 .5559 .578 221.5670 .630 .9217 .627 .9056 .573 .5490 .573 .6707 .585 .5671 .632 210.9290 .627 .9120 .564 .5885 .535 .6708 .582 .7409 .628 211.5055 .613 .9174 .562 .6164 .543 .8561 .569 221.7410 .633 .5378 .608 211.9224 .561 .6408 .579 218.8563 .566 230.6860 .686 .5605 .602 212.5370 .572 .6710 .525 219.5203 .593 230.6862 .686 .5882 .605 .5409 .565 .7275 .610 .5205 .604 231.8419 .683 .6144 .598 .5546 .571 .7493 .588 .5206 .608 231.8420 .681 .6548 .550 .5679 .577 .7759 .537 .6523 .587 211.7087 .564 212.6033 .575 213.7793 .558 219.6524 .584 TABLE Ib. Blue observations of HD 163868 JD(hel.) V-C JD(hel.) V-C JD(hel.) V-C JD(hel.) V-C JD(hel.) V-C 2442000+ 2442000+ 2442000+ 2442000+ 2442009+ 208.5858 +.637 211.7250 +.497 212.6076 +.554 213.8007 +.512 219.7567 +.540 209.6080 .604 .7291 .480 .6313 .522 .8328 .512 .7581 .539 209.9054 .581 .7348 .480 .6775 .522 .8368 .535 .7582 .534 210.5475 .550 .7547 .486 .7160 .541 213.3692 .538 .7583 .545 .5615 .535 .7743 .491 .7464 .539 215.8366 .495 .7583 .539 .6066 .541 .7985 .492 .7592 .547 .8370 .502 .8025 .543 .6649 .539 .8175 .494 .7812 .545 215.8372 .502 .8026 .543 .7427 .542 .8234 .495 .7977 .549 216.6817 .520 .8234 .560 .7899 .524 .8303 .493 .8304 .545 .6819 .523 .8235 .554 .0240 .533 .8514 .497 .8348 .542 .7103 .560 .8752 .548 .2375 .549 .8542 .513 .8624 .529 .7107 .579 219.8760 .537 .3462 .546 .8694 .498 .8667 .532 216.7109 .582 220.5416 .553 .894E .563 .8736 .501 .8945 .522 218.5564 .524 .5413 .555 .9039 .552 .8795 .501 212.9278 .515 .5567 .527 .8638 .543 .9154 .557 .8974 .497 213.5269 .502 .6712 .536 220.8640 .552 .9218 .551 .9058 .504 .5491 .509 .6714 .536 221.5674 .576 210.9291 .552 .9122 .495 .5887 .467 .6716 .528 .5676 .576 211.5058 .555 .9176 .489 .6166 .469 .8565 .526 .7412 .564 .5380 .530 211.9225 .496 .6410 .504 218.8567 .523 221.7414 .572 .5606 .528 212.5372 .519 .6712 .467 219.5213 .547 230.6864 .602 .5884 .520 .5412 .524 .7277 .494 .5214 .553 230.6866 .612 .6155 .521 .5548 .502 .7495 .506 .6527 .547 231.8422 .594 .6550 .466 .5682 .519 .7760 .462 .6534 .542 231.8423 .584 211.7089 .484 212.6035 .512 213.7795 .487 219.7566 .543