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* * * * * C/1999 S4 (LINEAR) * * * * *
lightcurve Year Mn Day MM Mag Ref Scope Pwr coma DC tail p.a. Obs Site 2000 8 30.43 [12.5 HS 20.0L 160 MAT Wallaroo, SA 2000 8 6.40 S 10.0:TJ 20.0L 45 2 1 5m 95 MAT Wallaroo, SA (Subtle brightening at the head. Moonlight interference.) 2000 8 2.44 S 9.0:TJ 10.0B 25 4 0 18m 90 MAT Wallaroo, SA (Magnitude estimate is on the surface brightness of the tail using Sidgwick method.) 2000 8 2.35 S 9.0 AA 10.0B 25 4 1 0.3 95 SEA The Entrance, NSW (Diffuse and elongated object. Seemed a little fainter when observed through Swan Band filter.) 2000 8 1.43 S 9.0:TJ 10.0B 25 3 0 20m 90 MAT Wallaroo, SA (Trying to make a magnitude estimate on a headless comet is quite difficult.) 2000 7 31.43 S 8.5 TJ 10.0B 25 3 1 20m 95 MAT Wallaroo, SA (There is hardly any nuclear condensation remaining. The "head" appears cigar shaped, indicating nuclear disruption has occured.) 2000 7 29.35 S 8.2 AA 10.0B 25 0.3 85 SEA The Entrance, NSW (Nebulous streak brighter at end nearest sun. The brighter end took the form of an oval coma without condensation. Appearance virtually unchanged thro' Swan Band filter, but may have been a little clearer with filter. Unusual appearance, but very similar to C/1989 W1 (Aarseth-Brewington) on January 23 and 24, 1990.) 2000 7 27.40 S 7.6 TJ 10.0B 25 3 3 0.5 90 MAT Wallaroo, SA (Comet is much fainter than predicted and quite diffuse.) 2000 7 26.36 S 6.5:AA 10.0B 25 SEA Cowra, NSW 2000 7 21.92 S 6.0 TJ 3.4B 9 & 7 4 1.8 10 PER Cabo da Roca (In 9x34B 1.6 deg. gas tail near p.a. 33 deg.; 1.8 deg. clock-wise curved dust tail near p.a. 10 deg.) 2000 7 21.91 S 6.0 TJ 10.0B 14 & 6 4/ 1.3 34 PER Cabo da Roca (An impressive increase in brightness since my last observation 24h ago! In 14x100B 1.3 deg. gas tail near p.a. 34 deg.; 1.0 deg. clock-wise curved dust tail near p.a. 7 deg.; superb transparency.) 2000 7 20.92 S 6.7 TJ 10.0B 14 & 5 4 1.0 19 PER Cabo da Roca (1.0 deg. gas tail near p.a. 19 deg.; 1.0 deg. clock-wise curved dust tail near p.a. 352 deg.) 2000 7 15.06 S 7.1 TJ 10.0B 14 & 4 5 0.5 300 PER Cabo da Roca (strong moonlight.) 2000 7 13.018 M 7.5 TJ 8.0B 15 4 6 0.8 286 BOU Sint Annen 2000 7 13.010 M 7.5 TJ 15.6L 24 3.5 6/ 0.6 281 BOU Sint Annen 2000 7 11.12 S 7.8 TJ 10.0B 14 & 3 5 1.2 260 PER Cabo da Roca (1.2 deg. dust tail curving noticeably clockwise ; 1 deg. gas tail near p.a. 280 deg; all comparison stars within less than 1 deg. from the comet's altitude (32 deg.); with modified-out method m1=7.8, with VBM method m1=7.9, but tail rather bright near comet's head, and blending in the defocused comet image with these two methods; coma diameter (as usual) measured along the direction orthogonal to that bisecting the two tails.) 2000 7 11.004 M 7.5 TJ 8.0B 15 6 5 40m 276 BOU Sint Annen 2000 7 10.997 M 7.7 TJ 30.5T 56 & 7 5/ 0.9 COM Roden 2000 7 5.08 S 8.3 TJ 10.0B 14 & 3 3 0.4 255 PER Cabo da Roca (0.4 deg. fan tail spanning p.a. 242-270 deg; all comparison stars within less than 1 deg. from the comet's altitude (23 deg.)) 2000 7 3.85 !M 8.0 TJ 10.0B 25 4 6 MAT Wallaroo, SA (Comet at 4 deg altitude. Magnitude corrected for extinction. Short tail noted at PA ~280 deg.) 2000 6 30.997 M 8.4 TJ 30.5T 56 4.5 4 0.2 COM Roden 2000 6 30.989 S 8.3 TT 8.0B 15 4.5 6 14m 265 BOU Sint Annen (In 31.0-cm reflector at 72x broad fantail, some 20-30 deg wide, with rather bright northern edge near the central condensation, longest 14' in p.a. 265 deg. At 186x tiny nearly stellar nucleus visible of magn. ~13.5, near apex of parabolic (dust) fan.) 2000 6 30.08 S 8.2 TJ 10.0B 14 & 6 4 10m 265 PER Cabo da Roca (All comparison stars within less than 1.5 deg. from the comet's altitude (20 deg.); superb transparency with mag 10.4 stars visible in my smaller 9x34B.) 2000 6 14.15 S 8.9 TJ 10.0B 14 4 4/ PER Cabo da Roca (Mag 10.9 star in coma, affecting m1 by about 0.15 mag. (the tabulated m1 was corrected for this effect); all comparison stars within less than 1 deg. from the comet's altitude (23 deg.); observation with the Moon 2 deg. above W horizon, and the Sun at -16 deg.) 2000 6 13.14 S 8.9 TJ 10.0B 14 & 4 5 PER Cabo da Roca (Mag 11.6 star in coma (affecting m1 by less than 0.1 mag); all comparison stars within less than 1 deg. from the comet's altitude (20 deg.); observation after moonset, and just at the start of astronomical twilight.) 2000 6 12.85 S 9.9 TJ 15.0L 40 2.0 5 MAT Wallaroo, SA (Observation made at low altitude. Comet is moderately condensed - a good sign of things to come.) 2000 6 8.014 S 10.2:TT 25.4J 72 2.5 2/ BOU Sint Annen (Comet faintly, but definitely visible, despite strong twilight and low altitude of only 10 degrees.) 2000 2 28.795 S 12.9 GA 25.4J 100 1.0 2/ BOU Sint Annen 2000 2 25.808 S 13.1 GA 25.4J 100 1.0 2/ BOU Sint Annen 2000 2 2.797 S 13.5 GA 25.4J 100 1.2 3 BOU Lauwersoog 1999 11 17.199 S 14.2 HS 30.0L 150 0.7 2 BOU Poio, Portugal 1999 11 15.983 S 14.2 HS 30.0L 150 0.7 3 BOU Poio, Portugal 1999 11 14.970 S 14.2 HS 30.0L 150 0.6 3 BOU Poio, Portugal 1999 11 13.983 S 14.2 HS 30.0L 150 0.6 2/ BOU Poio, Portugal 1999 11 12.921 S 14.3 HS 50.0L 226 0.7 2 BOU Poio, Portugal 1999 11 11.939 S 14.1 HS 30.0L 150 0.6 2 BOU Poio, Portugal 1999 11 9.917 S 14.3 HS 30.0L 150 0.6 2/ BOU Poio, Portugal 1999 11 7.956 S 14.4 HS 30.0L 150 0.6 2 BOU Poio, Portugal 1999 11 6.97 S 14.6 HS 30.0L 150 0.5 4 COM Poio, Portugal 1999 11 6.963 S 14.3 HS 30.0L 150 0.6 2 BOU Poio, Portugal (Reality and motion of observed object confirmed in 50-cm reflector at 226x.) 1999 10 17.017 S[14.8 HS 40.0L 270 !0.5 BOU Lattrop