* * * * * C/2021 D1 (SWAN) * * * * *

Year Mn Day    MM  Mag Ref Scope Pwr coma  DC tail p.a. Obs  Site
2021  4  5.85   S  9.7 TK  20.3T  77   8   2/           GON  Alto del Castro - Aralla, León
(Altitude 19°. Zodiacal light.)
2021  3 30.830  S 11.2 AQ  15.5L  50  1.9  4            DIJ  Burlage
(Altitude comet 17.2° with Sun at -16.8°. Comet 1.1' from 12.0 magn star.) 
2021  3 29.816  S 10.8 AQ  15.5L  42  2.2  4            DIJ  Burlage
(Altitude comet 19.2° with Sun at -14.6° and Moon at +3.6°.)
2021  3 25.816  S 10.5 AQ  15.5L  50  2.2  4            DIJ  Burlage
(Altitude comet 17° with Sun at -15.7°. Moon in clouds.) 
2021  3 17.809  S 10.9 AQ  25.4J  72  2.5  3            BOU  Westerwijtwerd
(Moonlight [16.7% illuminated]. Altitude comet 14.3° with Sun at -15.9°.)
2021  3 15.83   S  9.2 TK  20.3T  77   8   2/           GON  Alto del Castro - Aralla, León
(Observation made under better conditions, providing a wider coma diameter and brighter m1 estimate in comparison with my previous observation. Altitude 14°.)
2021  3 12.83   S  9.7 TK  20.3T  77   5   3            GON  Alto del Castro - Aralla, León
(Altitude 11°. Zodiacal light.)
2021  3  6.798  S 11.1 AQ  25.4J  72  1.8  3/           BOU  Westerwijtwerd
(Faint, diffuse object close to star of magn. 10.8. Altitude comet 9.3° with Sun at -16.8°.)