* * * * * C/2009 F6 (Yi-SWAN) * * * * *

Year Mn Day    MM  Mag Ref Scope Pwr coma  DC tail p.a. Obs  Site
2009  5 26.91   S  9.3:TK  20.3T 100   5   3            GON  Alto del Castro - Aralla, León
(Several stars in coma, the brightest being mag 10.9 [TK]. Astronomical twilight. Altitude: 9 deg.)
2009  5 21.973  S  9.0 TK  15.5L  50  3.5  2/           DIJ  Burlage
2009  5 21.021  S  9.0 TK  15.5L  50  2.5  1/           DIJ  Burlage
(Very low, app. 8 degrees, but very well seen.)
2009  5 19.938  S  9.5 TK  31.0J  58  3.3  2            BOU  Sint Annen
2009  5 18.950  S  9.0 TK  15.5L  50  2.0  1/           DIJ  Burlage
2009  5 18.92   S  9.1 TK  20.3T  77   6   3/           GON  Alto del Castro - Aralla, León
(Altitude: 11 deg.)
2009  5 12.938  S  9.1 TK  15.6L  36   4   2/           BOU  Sint Annen
2009  5 12.903  S  8.8 TK  15.5L  50   3   1            DIJ  Burlage
2009  5 11.907  S  8.4 TK   8.0B  15   4   2/           DIJ  Burlage
2009  5  2.13   S  9.2 TK  20.3T  77  3.5  3/           GON  Alto del Castro - Aralla, León
(Altitude: 12 deg.)
2009  5  2.11   S  9.8 TK  40.7L  58  4.0  2            BIV  Versailles
2009  4 24.868  S  8.7 TK  15.5L  50  3.5  3            DIJ  Burlage
2009  4 23.86   S  9.5 TK  40.7L  58  2.5  3            BIV  Versailles
2009  4 20.903  S  8.6 TK  31.0J  58  3.5  4            BOU  Lauwersoog
2009  4 20.889  S  8.6 TK  15.5L  50  3.2  3/           DIJ  Burlage
2009  4 20.88   S  9.2 TK  10.0B  25   4   4            GON  Alto del Castro - Aralla, León
2009  4 20.15   S  9.3 TK  20.3T  77   4   3            GON  Alto del Castro - Aralla, León
2009  4 19.001  S  8.6 TK  31.0J  58  3.0  3            DIJ  Burlage
2009  4 18.997  S  8.6 TK  31.0J  58  3.5  4            BOU  Burlage, Germany
2009  4 18.90   S  8.6 TK  10.0B  30   4   4            GIL  Noordwijk aan Zee
2009  4 17.960  S  8.5 TK  15.5L  50   4   3/           DIJ  Burlage
2009  4 17.886  S  8.4 TK  15.6L  36   4   4            BOU  Sint Annen
(Star of magn. 9.8 [TK] near edge of coma.)
2009  4 15.867  S  8.5 TK  15.6L  36   4   3/           BOU  Sint Annen
2009  4 15.862  S  8.4 TK   8.0B  15  3.5  2            DIJ  Burlage
2009  4 12.86   S  8.2 TK  10.0B  25   6   5            GON  Alto del Castro - Aralla, León
2009  4 11.88   M  8.4 TK  10.0R  25   5   4            GRA  Årnes
(Comet fairly well visible despite its location only 0.4 deg. from α Cas. Somewhat hazy, NEL = 5.5 [approx.].)
2009  4 11.861  S  8.3 TK   8.0B  15       3/           DIJ  Burlage
2009  4 10.93   V 10.6 TK  10.2R      2.0               QVA  Borrevannet, Horten
2009  4 10.832  S  8.3 TK   8.0B  15  3.5  3            DIJ  Burlage
(Comet close to a magn. 7.9 star. Comet is fast moving.)
2009  4  7.06   M  8.5 TK  20.3T  77   4   3            GRA  Fjellhamar
(Using 20.3cm-T at 77x, the comet showed a diffuse coma of quite low surface brightness; it was seen at
R.A. = 00h01m.2, Decl. = +55o00' [2000.0]. This comet was also detected, albeit with difficulty, using
10.2-cmR at 25x. Moonlight [NEL approx. 5.0].)
2009  4  6.16   S  8.1 TK  10.0B  25   7   5            GON  Sasamón, Burgos
2009  4  6.15   S  8.2 TK  15.2S  50   6   4            GON  Sasamón, Burgos
(Mountain location, very clear sky. Altitude: 28 deg. Clear motion observed over 60 min period.
Visual astrometry: R.A. = 23h54m.0, Decl. = +54o41'.5 [equinox 2000.0].)