# IBVS 2076-t1.txt # IBVS 2246-t88.txt #IAU COMMISSION 27 UNPUBLISHED DATA FILE 88 #IBVSdataKey: photometry #Object: theta1 Ori A #Author: Douglas S. Hall and J. R. Sowell IAU COMMISSION 27 - UNPUBLISHED DATA FILE # 88 PHOTOMETRY OF theta1 ORI A Differential photoelectric magnitudes (theta1 Ori A - theta2 Ori B) are listed. theta2 Ori B has been used as a comparison star. All measurements have been corrected for differential atmospheric extinction and transformed differentially to the UBV system. A diaphragm 11 arcseconds in diameter was used for both the variable and the comparison stars. Consequently, each measure of the variable includes the light of theta1 Ori E, the faint companion star about 4 arcseconds away. The sky offset for the variable star was always taken at a point in the Orion Nebula 18 arcseconds due South of the variable. Phases in the three tables have been computed with the ephemeris JD(hel.) = 244 3144.600 + 65d.43233 E. These data are refered to by Sowell and Hall, in a paper submitted to the Information Bulletin of Variable Stars in 1981. 4 pages, including cover sheet September, 1981 Douglas S. Hall and J. R. Sowell Dept. of Physics and Astronomy Vanderbilt University Nashville, TN 37235 ********************************************************************** page 2 82 TABLE 17 DYER - SOWELL 1979-80 V theta1 ORI A DATA ---------------------------------------------------------------------- ---------------------------------------------------------------------- HJD PHASE delta V 2,440,000+ ---------------------------------------------------------------------- 4191.7021 0.00283 0.859 4191.8220 0.00466 0.516 4191.8892 0.00569 0.398 4191.9417 0.00649 0.313 4191.9890 0.00720 0.387 4192.7220 0.01842 0.315 4194.7354 0.04919 0.276 4210.6939 0.29308 0.306 4212.7081 0.32390 0.287 4222.7031 0.47660 0.286 4223.7819 0.49311 0.315 4223.8326 0.49388 0.307 4223.8714 0.49450 0.276 4225.7065 0.52250 0.278 4240.7116 0.75184 0.316 4257.6702 0.01102 0.309 4293.5662 0.55962 0.308 4320.5396 0.97185 0.315 4320.5609 0.97218 0.320 4320.5757 0.97240 0.308 4320.5920 0.97265 0.316 ---------------------------------------------------------------------- ********************************************************************** page 3 83 TABLE 18 DYER - SOWELL 1979-80 B theta1 ORI A DATA ---------------------------------------------------------------------- ---------------------------------------------------------------------- HJD PHASE delta B 2,440,000+ ---------------------------------------------------------------------- 4191.7203 0.00311 0.913 4191.8503 0.00510 0.547 4191.9074 0.00597 0.406 4191.9584 0.00675 0.440 4192.7357 0.01863 0.441 4194.7492 0.04940 0.406 4210.7097 0.29332 0.413 4223.7973 0.49334 0.448 4223.8451 0.49407 0.432 4240.7210 0.75199 0.447 4257.6775 0.01113 0.452 4320.5467 0.97196 0.441 4320.5685 0.97229 0.441 4320.5835 0.97252 0.425 4320.6003 0.97278 0.428 ---------------------------------------------------------------------- ********************************************************************** page 4 84 TABLE 19 DYER - SOWELL 1979-80 U theta1 ORI A DATA ---------------------------------------------------------------------- ---------------------------------------------------------------------- HJD PHASE delta U 2,440,000+ ---------------------------------------------------------------------- 4191.7357 0.00335 0.934 4191.8692 0.00539 0.590 4191.9259 0.00625 0.465 4192.7499 0.01884 0.481 4194.7640 0.04963 0.462 4210.7262 0.29358 0.491 4223.8125 0.49357 0.482 4223.8590 0.49428 0.491 4240.7305 0.75213 0.462 4257.6856 0.01126 0.443 ---------------------------------------------------------------------- **********************************************************************