Circular No. 3459 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758 PERIODIC COMET HALLEY F. L. Whipple, Harvard-Smithsonian Center for Astrophysics, communicates: "From 60 measures of 'halo' diameters on Lowell Observatory plates of P/Halley during 1910 Jan. 8-June 25, I find a single rotation solution of 0d.4297 or 10h19m (sidereal), fitting all 45 normal places with sigma = +/-0d.088. Eight diameters by J. Herschel in 1835-36 give the same period. Probably the rotation and orbital poles are close together with motion in the same sense as indicated by the nongravitational motions derived by Kiang and Yeomans. For mission planning in the 1985-86 apparition, early observations should provide good predictions of nucleus active-area orientation." SS 433 G. H. Newsom and G. W. Collins, II, Department of Astronomy, Ohio State University, write: "We find the presence of a statistically-significant short periodicity in the wavelengths of each of the 'moving' emission lines in SS 433, superimposed on the 165-d variation. If light-travel time is negligible in the system, periods of both 6d.30 +/- 0d.01 and 6d.06 +/- 0d.01 appear. If we include light-travel time in a large highly-inclined system (1100 AU radius; i = 22o) as described by Collins, Newsom and Boyd (preprint), the dominant period is 6d.55 +/- 0d.01. We note that the 6d.55 period is half the 13d.0 period reported by Crampton et al. (IAUC 3388). However, more observations are necessary to determine which period is fundamental and which are probable 'aliases' resulting from non-uniform data distribution." 2A 0311-227 J. B. Hutchings, A. P. Cowley and D. Crampton, Dominion Astrophysical Observatory, report: "Single-trailed spectrograms of 20-min duration were taken of this source with the 4-m reticon spectrograph at Cerro Tololo Interamerican Observatory. These reveal a complex emission-line structure in which two peaks merge and separate roughly every 12 min. The Balmer lines generally have a stronger component moving from long to short wavelengths, while the He II 468.6-nm components have more equal or reversed intensity ratios. The phenomenon is presumably connected with the 6-min oscillations in optical light noted by Williams et al. (1979, Nature 281, 48) and seems similar to the 71-s oscillation seen in DQ Her." 1980 March 13 (3459) Daniel W. E. Green
Our Web policy. Index to the CBAT/MPC/ICQ pages.