COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 3602 Konkoly Observatory Budapest 8 May 1991 HU ISSN 0374 - 0676 A CONTINUATION OF QUASI-PERIODIC BEHAVIOR FOR HD 45677 = FS CMa HD 45677 = FS CMa is not an "ordinary" member of the class of Be stars. It has been suggested to be an object intermediate between these and the planetary nebulae or else a symbiotic object since it possesses an extended shell of gas and dust of considerable density. Its spectral type has been classified in the range B0p (Rufener 1981) to B3 V (Low et al. 1970), but it possesses strong emission lines both permitted (hydrogen) and forbidden (Fe II, Ni II, Cr II, S II, O I). Partly due to its strong infrared excess, it has been suggested that it is binary with a very late-type giant/supergiant or perhaps an infrared object still in the process of formation (Ciatti al. 1974). Alternately, Allen (1971) suggested that the excess is caused by H-free-free emission. Recently Sorrell (1989) modelled the far UV to far IR energy distribution as a spherical dust shell (a fossil from the star's formation surrounding a single hot young [< 10^8 years] object). Halbedel (1989) has published four years of photometry for HD 45677 which showed two types of variation: a quasi-periodic 296.5 day V mag variation superimposed on a >3 year change. This paper reports on a further two years of observations for the star. All recent differential photometry was obtained with the 0.6-m. telescope of the Corralitos Observatory and its ambient temperature EMI 9924A-based pulse-counting photometer. Comparison stars used were HD 45495 (V=8.375; B-V=-.027) and HD 45629 (V=7.091; B-V=-.032). They [FIGURE 1] FIGURE 1: MAGNITUDES FOR HD 45677. THE TOP DIAGRAM SHOWS V MAGNITUDE, THE BOTTOM B-V. TABLE 1: MAGNITUDES FOR HD 45677 JD JD (2440000+) V B-V (2440000+) V B-V 7793.96806 8.490 +.060 7965.67361 8.389 +.091 7806.93750 8.471 .057 7983.62222 8.386 .049 7809.93958 8.430 .073 8159.97916 8.255 .094 7827.96111 8.466 .065 8161.95138 8.314 .109 7878.88680 8.313 .077 8176.92986 8.394 .077 7880.85694 8.371 .075 8205.86805 8.291 .108 7881.77222 8.340 .098 8225.86042 8.154 .092 7896.76736 8.349 .075 8243.72569 8.174 .060 7897.76874 8.346 .092 8292.78542 8.138 .065 7915.71805 8.328 .113 8313.68748 8.059 .112 7917.75347 8.408 .088 8328.65694 8.071 .072 7933.61736 8.352 .034 8347.64653 8.023 .091 7952.66250 8.413 .088 8350.62500 8.005 ---- were found to be stable to 0.016 in V and 0.017 in B-V over the time period of observation. The thusfar unpublished magnitudes for HD 45677 are set forth in Table 1, and appear graphically along with the previous data in Figure 1. It may be seen that the star still undergoes both short and long cycle time behavior. At present it is brighter than it has been for some time, but there has been no concomitant color change. A period search utilizing the Minimum Phase Dispersion Technique of Stellingwerf (1978) and all 6 years of data finds that the best quasi-period is still similar, 296.7 days, though the scatter in the phase diagram is greater than when this analysis was previously done for only 4 observing seasons. It seems unlikely that this is anything but a temporary phenomenon since FS CMa has undergone long "stand stills" in the past. Therefore, it is not likely connected with binary motion unless it proceeds from semi-regular light variations of a companion late-type star. Still, it is of interest that quasi-periodicity has persisted for six years thusfar. HD 45677 will continue to be observed at the Corralitos Observatory indefinitely. E.M. HALBEDEL Corralitos Observatory P.O. Box 16314 Las Cruces, NM U.S.A. 88004-6314 REFERENCES Allen, D.A. 1971, PASP, 83, 602 [BIBCODE 1971PASP...83..602A ] Ciatti, F., D'Odorico, S. & Mammano, A. 1974, A&A, 34, 181 [BIBCODE 1974A&A....34..181C ] Halbedel, E.M. 1989, PASP, 101, 999 [BIBCODE 1989PASP..101..999H ] Low, F.J., Johnson, H.L., Kleinmann, D.E., Latham, A.S., & Geisel, S.L. 1970, ApJ, 160, 531 [BIBCODE 1970ApJ...160..531L ] Rufener, F. 1981, A&AS, 45, 207 [BIBCODE 1981A&AS...45..207R ] Sorrell, W.H. 1989, MNRAS, 241, 89 [BIBCODE 1989MNRAS.241...89S ] Stellingwerf, R.F. 1978, ApJ, 224, 953 [BIBCODE 1978ApJ...224..953S ]