* * * * * 73P/Schwassmann-Wachmann 3-BT * * * * *

Year Mn Day MM Mag Ref Scope Pwr coma DC tail p.a. Obs Site 2017 3 6.73 M 12.2 AQ 25.0L 83 0.9 3/ 2.4m 265 WYA Walcha, NSW (Faint tail. Inner coma appears elongated East-West. Brightness is combined magnitude of fragments C and BT.) 2017 2 23.77 S 11.1 AQ 40.6L 165 1.4 2 CAM Warners Bay, NSW 2017 2 23.72 M 11.9 AQ 25.0L 83 1.1 3/ WYA Walcha, NSW (Coma elongated to the West approximately; Inner coma opaque. Does not enhance in Swan Band filter.) 2017 2 22.76 S 10.8 AQ 40.6L 165 1.0 2 CAM Warners Bay, NSW 2017 2 21.23 S 9.8 TK 20.3T 100 3.5 2 GON Alto de la Camperona, León (The visually observed faint and wide halo-like common coma of 73P is surrounding the primary and the brighter secondary component BT [this secondary is evolving after the recent outburst recorded in CCD images]. Both central condensations were not individually detected in the present observation due to faintness, small separation [near 0.5'], instrumental and observing conditions: interference from the nearby Moon [phase 0.28] and low altitude [9°] at the start of astronomical twilight. Field stars checked in DSS. Background star of mag 12.3 [GSC] in coma.) 2017 2 19.71 S 11.0 TK 40.6L 76 1.3 2/ CAM Warners Bay, NSW 2017 2 17.72 S 10.8 AQ 25.0L 83 1 2/ WYA Walcha, NSW (Moonlight. Coma small, diffuse and opaque. Slight brightening to centre, no enhancement in Swan Band filter.)