Circular No. 4169 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 617-495-7244/7440/7444 R AQUARII R. Viotti and L. Rossi, Istituto Astrofisica Spaziale, Frascati; A. Cassatella, European Space Agency and IUE Observatory, Villafranca; and L. Piro, Istituto TESRE, Bologna, telex: "The symbiotic Mira-type variable R Aqr was observed with EXOSAT on 1985 Dec. 24 near the Mira light minimum. The x-ray flux appears weak and close to that detected in 1985 June (IAUC 4083). Coordinated IUE observations of R Aqr and its jet made at Vilspa on Dec. 23 show no large changes in the ultraviolet spectrum with respect to previous 1985 observations and confirm a higher temperature for the jet (IAUC 4157). These results indicate that x-rays do not originate from the Mira giant, but rather in the circumstellar region of a hot companion. Reanalysis of the previous 1980 Einstein Observatory observations suggests that the marginal detection (Jura and Helfand 1984, Ap.J. 287, 785) actually is only an upper limit." PERIODIC COMET HALLEY (1982i) C. Barbieri, T. Iijima and F. Sabbadin, Asiago Astrophysical Observatory, report that further prismatic spectra (cf. IAUC 4138; range 386-700 nm; east-west slit) obtained on Jan. 15.7, 17.8 and 20.8 UT showed the following emission features: CN (388.3, 421.5 nm), C2 (437.1, 468.4, 469.7, 471.3, 473.7, 500.5, 512.9, 516.4, 554.1, 558.5, 563.5, 619.1 nm), C3 (401.9, 404.0, 405.2, 407.4, 410.0 nm), CH (429.7, 430.4, 431.3, 434.1 nm), CH+ (423.1, 423.9 nm), NH2 (495.5, 570.3, 573.2, 609.8, 612.1 nm), [O I] (630.0 nm). Strong Na I emission was observed on the eastern side of the nucleus on Jan. 15.7; this was weaker on Jan. 17.8 but again intense on Jan. 20.8. On the western side the Na emission was always very faint. No other emission line shows such a rapid intensity variation and strong asymmetry with respect to the nucleus. Total visual magnitude estimates: Jan. 18.96 UT, 4.2 (D. W. E. Green, Cambridge, MA, 7 x 50 binoculars); 21.10, 4.3 (C. E. Spratt, Victoria, BC, 11 x 80 binoculars; tail 2 deg in p.a. 55); 21.73, 4.1 (J. D. Shanklin, Cambridge, England, 20 x 80 binoculars; tail 60' in p.a 65); 23.96, 3.5 (Green, Harvard, MA, 20 x 80 binoculars); 24.95, 3.7 (Green, Cambridge, MA, 20 X 80 binoculars). 1986 January 27 (4169) Brian G. Marsden
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