THE ASTRONOMER Electronic Circular No 531 1991 June 16 10.56UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP, England. Telephone: (0256)471074 Int:+44256471074 Telex: 9312111261 Answerback: TA G JANET BOXES: GMH at UK.AC.CAM.ASTRONOMY.STARLINK or GUYH at UK.AC.SUSSEX.CLUSTER TELECOM GOLD: 10074:MIK2885 PRESTEL 256471074 ------------------------------------------------------------------- COMET HELIN-ALU (1991r) Eleanor Helin and Jeff Alu report their discovery of a comet on films taken by Helin, K. Lawrence, P. Rose, and C. Brewer with the 0.46-m Schmidt telescope at Palomar. The object is diffuse with no apparent tail. 1991 UT R.A. (1950) Decl. m1 June 13.32257 16 35 54.60 -22 25 54.7 16 14.32899 16 35 23.58 -22 18 26.4 IAUC 5292 COMET LEVY (1991q) The following precise positions have been reported: 1991 UT R.A. (1950) Decl. m1 Observer June 14.74375 1 43 56.57 +13 41 32.5 7.5 Koishikawa 14.74826 1 43 57.82 +13 41 55.3 " 15.82374 1 48 47.86 +14 30 15.0 McNaught M. Koishikawa (Sendai Obs., Ayashi station). 300-mm telephoto lens. R. H. McNaught (Siding Spring). Communicated by A. C. Gilmore. Total visual magnitude estimates: June 15.43 UT, 9.6 (A. Hale, Las Cruces, NM, 0.41-m reflector; 2'-3' coma); 15.44, 8.5 (C. S. Morris, Pine Mountain Club, CA, 20x80 binoculars; 4'.4 coma). IAUC 5292 SUPERNOVA 1991ag IN IC 4919 M. M. Phillips, Cerro Tololo Interamerican Observatory; and J.Maza, University of Chile, report: "Roberto Antezana (University of Chile) has discovered a supernova located about 10" west and 33" north of the nucleus of IC 4919 (ESO 185-G43; R.A. = 19h56m11s, Decl. = -55 30'.7, equinox 1950.0). The supernova (mpg about 15) was found on a 20-min unfiltered IIa-O plate taken by M. Hamuy (CTIO) with the CTIO Curtis Schmidt telescope on June 9.19 UT. The ninth-magnitude star SAO 246378 is located 50" east of the galaxy nucleus. A CCD spectrum (range 325.0-750.0 nm) obtained on June 12.2 by Phillips with the CTIO 4.0-m telescope shows that this is a type-Ia supernova about 1 week past blue maximum. A spectrum of the nucleus of IC 4919 obtained with the same telescope and instrument yields a redshift of 0.0144." IAUC 5287 SUPERNOVA 1991ah IN ANONYMOUS GALAXY J. Maza, University of Chile; and M. M. Phillips, Cerro Tololo Interamerican Observatory, report: "Roberto Antezana (University of Chile) has discovered a supernova located about 5" W and 6" N of the nucleus of an anonymous galaxy at R.A. = 22h07m01s.7, Decl. = -46 34'10" (equinox 1950.0). The supernova (mpg about 18.5) was found on a 20-min unfiltered IIa-O plate taken by M. Hamuy (CTIO) with the CTIO Curtis Schmidt telescope on June 9.379 UT. Confirmation was made by M. Navarrete (CTIO) from a CCD image obtained on June 13.25 with the CTIO 0.9-m telescope. A CCD spectrum (range 551.5-1020.0 nm) obtained on June 13.26 by Phillips with the CTIO 4.0-m telescope shows that this is a type-II supernova with strong and relatively narrow (1400 km/s FWHM) H-alpha emission at a measured redshift of 0.037." IAUC 5290 Guy M Hurst