* * * * * 71P/Clark * * * * *

Year Mn Day MM Mag Ref Scope Pwr coma DC tail p.a. Obs Site 2017 11 9.48 S 14.3 AQ 25.0L 166 0.5 2 WYA Walcha, NSW (Coma diffuse, visible in periods of good seeing.) 2017 10 26.39 S 12.7 AU 40.0L 257 0.6 2 YOS Kita-karuizawa, Gunma (Near limit due to the moonlight and low sky condition.) 2017 10 19.45 S 13.1 AQ 25.0L 83 1.5 2/ WYA Walcha, NSW (Coma very diffuse, slight brightening to centre.) 2017 10 12.40 S 13.0 AQ 25.0L 83 1.2 2 WYA Walcha, NSW (Coma diffuse, difficult to see.) 2017 9 22.45 S 12.2 AQ 25.0L 83 1.9 3 WYA Walcha, NSW (Busy star field, difficult.) 2017 9 19.44 S 12.4 AQ 25.0L 83 1.6 3 WYA Walcha, NSW (Coma diffuse, slight brightening to centre. Does not enhance in Swan Band filter.) 2017 9 15.42 S 12.5 AQ 25.0L 83 1.2 2/ WYA Walcha, NSW (Coma very diffuse.) 2017 8 23.43 S 12.7 AQ 25.0L 83 1 3 WYA Walcha, NSW (Coma diffuse, slight brightening to centre. Close to background stars, possibly just seeing central portions of the coma.) 2017 8 23.04 S 11.1 AU 22.0L 160 2 3/ GOI Araçatuba 2017 8 19.44 S 11.8 AQ 25.0L 83 2.1 3 WYA Walcha, NSW (Does not enhance in Swan band filter. Background star in coma.) 2017 8 17.42 S 11.9 AQ 25.0L 83 2 3 WYA Walcha, NSW (Weak central condensation, diffuse coma. Does not enhance in Swan Band filter.) 2017 8 14.44 M 12.0 AQ 25.0L 83 1.6 3/ WYA Walcha, NSW (Coma diffuse, slight interference by background stars.) 2017 8 12.40 S 12.0 AQ 25.0L 83 1.6 3 WYA Walcha, NSW (Coma diffuse and semi-transparent, weakly condensed centre.) 2017 8 11.44 S 11.5 AQ 40.6L 76 2.5 3 CAM Katherine, NT 2017 8 10.99 S 10.9 TK 22.0L 160 2 3 GOI Araçatuba 2017 8 10.45 S 11.8 AQ 40.6L 76 1.2 3 CAM Katherine, NT 2017 7 27.55 S 10.8 AQ 40.6L 76 1.5 4/ CAM Katherine, NT (Close to a 11th magn. star.) 2017 7 26.08 S 10.6 TK 22.0L 60 3 4 GOI Araçatuba 2017 7 25.43 M 10.9 AQ 25.0L 39 3.2 3/ WYA Walcha, NSW (Coma diffuse, moderately condensed centre.) 2017 7 24.51 S 10.7 AQ 40.6L 76 1.5 4 CAM Katherine, NT 2017 7 22.93 S 9.9 TK 20.3T 77 2.5 4/ GON Alto del Trichero - Soto y Amío, León (Altitude 10°.) 2017 7 20.51 S 10.5 TK 40.6L 76 1.5 5 CAM Katherine, NT 2017 7 15.01 S 10.5 TK 22.0L 60 3 4/ GOI Araçatuba 2017 7 14.94 S 9.8 TK 20.3T 77 2.5 4/ GON Alto del Castro - Aralla, León (Altitude 11°.) 2017 7 2.04 S 10.1 TK 20.3T 77 2.5 5 GON Alto del Castro - Aralla, León (Altitude 6°.) 2017 6 30.61 M 10.3 AQ 25.0L 39 3.1 6 WYA Walcha, NSW (Coma almost disappears in Swan Band filter. Semi-transparent outer coma, gradually brightening to an opaque centre with a small stellar central condensation.) 2017 6 28.08 S 10.3 TK 22.0L 60 4 4/ GOI Araçatuba 2017 6 26.51 S 11.0 AQ 40.6L 76 1.5 3 CAM Katherine, NT 2017 6 24.43 S 10.6 AQ 40.6L 76 1.5 5 CAM Katherine, NT 2017 6 23.06 S 10.3 TK 22.0L 60 4 4/ GOI Araçatuba 2017 6 22.48 M 10.4 AQ 25.0L 39 3.1 5/ WYA Walcha, NSW (Inner coma opaque, sometimes stellar at centre, outer coma fanned to the NW approximately. Centre enhances slightly in Swan Band filter.) 2017 6 21.77 S 10.5 TK 40.6L 76 1.5 5 CAM Katherine, NT 2017 6 21.53 M 10.5 AQ 25.0L 39 2.6 5/ WYA Walcha, NSW (Coma opaque at centre, semi-transparent outer coma.) 2017 6 21.17 S 10.3 TK 22.0L 60 4 4 GOI Araçatuba 2017 6 20.48 S 10.3 GA 25.4L 71 3.0 SEA Cowra, NSW (Less visible through Swan Band filter.) 2017 6 20.45 M 10.5 AQ 25.0L 39 2 4 WYA Walcha, NSW (Does not enhance in Swan band filter.) 2017 6 18.79 S 10.6 TK 40.6L 76 1.5 5 CAM Katherine, NT (Moonlight.) 2017 6 15.48 S 10.5 TK 40.6L 76 2.0 5 CAM Katherine, NT 2017 6 14.97 S 10.4 TK 20.3T 77 2.5 5 GON Puerto de Aralla, León 2017 6 14.43 S 10.5 TK 8.0B 20 2.0 5 CAM Katherine, NT 2017 6 13.43 S 10.6 TK 40.6L 76 2.0 5 CAM Katherine, NT 2017 6 12.43 S 10.2 TK 8.0B 20 2.0 5 CAM Katherine, NT 2017 6 5.80 S 10.5 AQ 40.6L 76 2.0 6 4.0m 290 CAM Katherine, NT 2017 6 3.21 S 10.8 AU 22.0L 60 2 4/ GOI Araçatuba 2017 5 31.002 S 11.1 AQ 15.5L 63 1.5 5 DIJ Burlage (Comet at 10° altitude.) 2017 5 30.14 S 10.9 AU 22.0L 60 2 4/ GOI Araçatuba 2017 5 29.004 S 11.2 AQ 15.5L 75 1.3 5 DIJ Burlage (Comet at 10.5° altitude.) 2017 5 29.71 M 11.3 AQ 25.0L 39 1.7 5/ 4.3m 289 WYA Walcha, NSW (Faint tail visible. Outer coma diffuse, brightening to an opaque centre, faintly stellar in periods of good seeing, whitish in colour.) 2017 5 27.50 S 11.0 AQ 40.6L 76 1.0 6 CAM Katherine, NT 2017 5 27.17 S 11.0 AU 22.0L 60 1.5 5 GOI Araçatuba 2017 5 26.51 M 11.1 AQ 25.0L 83 1 5/ WYA Walcha, NSW (Coma diffuse, bright central condensation, sometimes stellar. Coma appears larger at lower magnification.) 2017 5 25.12 S 11.6 AU 22.0L 60 1.5 5 GOI Araçatuba 2017 5 24.43 M 12.5 AQ 25.0L 83 0.8 6 WYA Walcha, NSW (Does not enhance in Swan Band filter. Outer coma opaque brightening to an opaque inner coma and stellar central condensation. Slight hint of coma elongation to the NW approximately.) 2017 5 24.02 S 11.2 TK 20.3T 100 2.2 3/ GON Puerto de Aralla, León 2017 5 20.985 S 11.7 AQ 30.5T 102 1.1 3 DIJ Burlage 2017 5 20.979 S 11.8 AQ 30.5T 102 1.2 3/ BOU Burlage, Germany (Altitude 12.0°.) 2017 5 6.75 M 12.4 AQ 25.0L 83 1.1 6 WYA Walcha, NSW (Hint of tail extending West. No enhancement in Swan Band filter.) 2017 5 6.29 S 12.0 AU 22.0L 160 1.5 2 GOI Araçatuba 2017 5 4.74 S 12.2 AU 40.0L 144 1.2 6 YOS Kita-karuizawa, Gunma (Very bright. I was surprised that it was easy to see.) 2017 4 30.75 S 12.6 AQ 40.6L 165 0.7 5 CAM Warners Bay, NSW 2017 4 28.76 M 12.7 AQ 25.0L 83 1.3 6 WYA Walcha, NSW (Does not enhance in Swan Band filter.) 2017 4 28.74 S 12.7 AQ 40.6L 165 0.8 4 CAM Warners Bay, NSW 2017 4 28.13 S 12.0 AQ 20.3T 133 0.9 4 GON Puerto de Aralla, León
2006 9 27.44 S 12.6 AU 40.0L 144 0.9 3 YOS Kita-karuizawa, Gunma (I could not see it at the highlight due to the bad weather or low location. But I could see it again before it went away. Unexpectedly, the comet was still visible visually. My estimation is 12.6 mag, but I felt it much fainter. The magnitude becomes 13.7 mag if I use the GSC as reference.) 2006 9 24.46 S 13.4 28.0T 133 2 2 MAT Blinman, SA 2006 8 27.92 S 11.8 TK 20.3T 100 1.5 3 GON Cueto Rosales - Riello, León (Altitude 7°.) 2006 8 21.40 S 11.6 GA 10.0B 25 SEA Cowra, NSW 2006 8 20.42 S 11.6 GA 10.0B 25 SEA Cowra, NSW 2006 8 19.46 S 11.6 GA 25.4L 71 SEA Cowra, NSW (Glimpsed in 25x100B at approx mag. 11.6, but close to star.) 2006 7 20.60 10.8 20.0L 62 3 5 MAT Linville, Queensland 2006 7 20.46 M 10.9 GA 25.4L 71 2.0 4 SEA Cowra, NSW 2006 7 7.05 S 10.3 TK 20.3T 77 2.0 5 GON Alto del Castro - Aralla, León (Altitude 6°.) 2006 6 21.42 S 10.7 GA 25.4L 71 SEA Cowra, NSW 2006 6 20.43 S 11.0 GA 25.4L 71 3 SEA Cowra, NSW 2006 6 5.12 S 10.9 TK 20.3T 100 1.7 4 GON Alto del Castro - Aralla, León 2006 5 26.10 S 11.7 TK 20.3T 100 1.2 4 GON Alto del Castro - Aralla, León 2006 5 4.72 S 12.4 AU 40.0L 144 1.3 4 YOS Kita-karuizawa, Gunma (It looked unexpectedly large.) 2006 5 4.05 S 12.8 AC 41.0L 72 1.2 3 RES Szamotuly-Galowo 2006 5 3.74 S 12.6 AU 40.0L 144 0.8 4 YOS Kita-karuizawa, Gunma 2006 5 2.76 S 12.7 HS 40.0L 144 0.7 3 YOS Kita-karuizawa, Gunma 2006 4 30.75 S 12.2 AU 40.0L 144 0.7 4 YOS Kita-karuizawa, Gunma (Unexpectedly bright already. Somewhat low and not easy to see. It looked small.)