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Back Circular No. 8349 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304 Phone 617-495-7440/7244/7444 (for emergency use only) COMET C/2001 Q4 (NEAT) J. Lecacheux, LESIA, Meudon Observatory; and E. Frappa, St-Etienne Planetarium, write: "We have observed the concentric dust shells of comet C/2001 Q4 with the Pic-du-Midi 1.05-m reflector during six 3-hr sessions from May 14 to 19, around the time of perihelion. Direct measurement of the radial expansion on consecutive exposures yields 163 +/- 20 m/s. From the measured 12000-km shell interval, a first approximation of P = 20.5 +/- 3 hr can be inferred for the period of nucleus rotation, suggesting the exclusion of any value shorter than 17-18 hr. Then by blinking images of the inner shell taken at 1-day or several-day interval(s), and assuming constant expansion velocity, we obtain a refined probable period P = 23.2 +/- 0.25 hr. We also followed a small dust jet rotating counterclockwise (facing the sun) on May 14; its estimated angular motion of about 16 deg/hr agreed with the above period. Fibrous-like features, not more 300 km wide, appear within the brightest shell at 10000-15000 km from the nucleus; they show a pure radial expansion and no other morphology change in 3 hr, and they recur in the following shell 0.9 day later. In fact, we observe a complex of 3 or or 4 muddled components (sub-shells), issued from so many active regions and with slightly different expansion rates." Further visual total-magnitude estimates: May 19.87 UT, 4.2 (V. Znojil, Brno, Czech Republic, naked eye); 22.91, 4.5 (M. Meyer, Ursenbach, Germany, naked eye); 24.91, 4.7 (A. Diepvens, Balen, Belgium, 20x50 binoculars); 27.90, 5.0 (A. Amorim, Florianopolis, Brazil, 7x50 binoculars); 30.92, 5.4 (J. J. Gonzalez, Asturias, Spain, 7x50 binoculars). SUPERNOVA 2004by IN NGC 7116 M. Armstrong, Rolvenden, U.K., reports his discovery of an apparent supernova (mag 18.9) on unfiltered CCD images taken on May 24.102 and 28.026 UT with a 0.35-m reflector. SN 2004by is located at R.A. = 21h42m41s.88, Decl. = +28o56'50".6 (equinox 2000.0), which is approximately 16" east and 1".9 north of the center of NGC 7116. Nothing was visible at this position on his images taken on 2001 July 15 and 2003 Dec. 17 (limiting mag about 19.5) and on Palomar Sky survey red and blue plates. M. Mobberley, Cockfield, U.K., confirmed the new object on an unfiltered CCD image taken on May 27.951 with a 0.35-m reflector. (C) Copyright 2004 CBAT 2004 May 31 (8349) Daniel W. E. Green