* * * * * C/2012 S1 (ISON) * * * * *

Year Mn Day MM Mag Ref Scope Pwr coma DC tail p.a. Obs Site 2013 12 4.26 I [8.0 TK 8.0R 30 GRA Røverkollen, Oslo (Nothing detected near ephemeris position, visually and and photographically [Canon EOS 100D DSLR + 100-mm FL lens]. This location was between stars HD 145894 [mag. VT = 7.0] and HD 146173 [VT = 8.0], both stars were detected. The 2' defocused limiting magnitude was 5.5 [YG, comparison object 18 Sco]. Altitude 5° [ephemeris location] and solar altitude -11°.) 2013 11 28.33 I[-4.0:AE 5.0B 10 GON Cueto Rosales, León (Negative daytime observing attempt. Very low altitude [5°]. Mountain location, very clear sky.) 2013 11 25.29 wI [3.5:TK 5.0B 10 !1.0 GON Sierra de Nuestra Señora - Castrocontrigo, León (Comet not seen. Very low altitude [4°]. End of nautical twilight. Mountain location, very clear sky.) 2013 11 23.26 wI 4.6 TK 5.0B 10 8/ 0.7 280 GON Andarraso, León (Near-stellar appearance. Very low altitude [5°]. Beginning of nautical twilight. The smaller apparent coma diameter [observed at lower altitude in twilight] could provide the fainter m1 estimate in comparison with my previous one. Mountain location, very clear sky.) 2013 11 22.26 !M 3.6:YG 8.0R 20 & 1 7 GRA Røverkollen, Oslo (Despite a challenging geometry the comet was detected both visually and photographically. Thanks to a very clear and transparent sky the comet was easier to observe than during the previous morning. The comet appeared parabola-shaped [coma + inner tail]. Formal estimates made at alt. 3.3° and solar alt. -9.3°. Deduced magnitude is approximate and corrected for extinction using an extinction coefficient of 0.15 mag. per airmass. Comparison objects were λ Vir, α2 Lib and Saturn.) 2013 11 21.32 sM 3.7 HD 10.0B 20 2 8 0.2 280 GOI Araçatuba (Comet altitude: 10°, civil twilight, Sun at -10°. Clouds.) 2013 11 21.31 sM 3.9 HD 5.0B 7 5 7 0.5 280 GOI Araçatuba 2013 11 21.31 sM 4.2 HD 10.0B 20 3 8 0.3 280 GOI Araçatuba (Comet altitude: 7°, nautical twilight, Sun at -12°. Clouds.) 2013 11 21.27 M 4.5:YG 8.0R 30 & 1 8 GRA Røverkollen, Oslo (Challenging observation due to bright sky [solar alt. -7.8°]. Comet only seen for a couple of minutes around 06h22m UT. Clouds prevented earlier observing. The coma appeared as a pale disk and was approximately equal in brightness to λ Vir. This star and Mercury [clearly seen to naked eye] were observed at nearly the same altitude as the comet [6.4°].) 2013 11 21.25 M 3.8 TK 5.0B 10 2 8/ 1.5 290 GON Aldeanueva de Figueroa, Salamanca (Near-stellar appearance. Very low altitude [7°]. Moonlight interference. Rural location, very clear sky.) 2013 11 21.238 S 4.3 TK 8.0B 15 4 8 DIJ Burlage (Comet at 5.5°, Sun at -11.8° altitude.) 2013 11 20.24 M 4.6 TK 5.0B 10 GRA Røverkollen, Oslo 2013 11 20.24 M 4.6 TK 8.0R 20 2 8 GRA Røverkollen, Oslo (In 10x50B, coma appeared small and considerably brighter compared to three mornings ago. With 8.0-cm R, a bright and compact coma that showed a nearly stellar central condensation of mag. 6.5 [TK], apparently an outburst in progress. Tail was not seen visually but appeared faintly on images [using a Canon EOS 100D camera and a 200-mm lens]. The green colour of the coma was detected both visually and photographically. No magnitude correction for extinction as the principal comparison star [69 Vir] was seen at nearly the same altitude as the comet [6°]. Formal observation made in nautical twilight [solar alt. -11°].) 2013 11 20.234 M 4.5:TK 8.0B 15 & 2 8 BOU Sint Annen (Moonlight. Comet at 6.6° and Sun at -13.1°. Some interference from variable amounts of cirrus. Comet small and strongly condensed. No tail visible under these conditions.) 2013 11 19.31 S 4.8 HD 5.0B 7 5 6 GOI Araçatuba 2013 11 19.31 M 4.9 HD 10.0B 20 3 7/ 0.3 290 GOI Araçatuba (Comet altitude: 10°. Nautical twilight, comparison stars at the same altitude.) 2013 11 19.18 M 5.0 TT 5.0B 10 3 8 GUZ Bogdanówka (Only faintly seen, almost stellar.) 2013 11 19.17 M 5.4 TT 32.6L 10 2 7/ 0.1 290 GUZ Bogdanówka (Bright, well condensed, green object. Moonlight interference. Observed between cirrusbands.) 2013 11 18.74 S 5.8 AA 10.0B 25 & 3 7 SEA Cowra, NSW (Possible trace of tail to SW glimpsed.) 2013 11 18.74 M 5.7 TK 7.0B 11 5 5/ WYA Walcha, NSW (No tail, coma diffuse with small central condensation. Bright moonlight and twilight interference. Low alt. 9.6°. Lost sight of comet through 11x70Bs at 18.75 UT. Coma diameter is approximate.) 2013 11 17.32 M 4.7 TK 10.0B 20 3 7 GOI Araçatuba (Comet altitude 16°. Civil twilight, Sun: -10°, clouds.) 2013 11 17.23 M 5.8 TK 8.0R 20 4 7 GRA Røverkollen, Oslo (Using 8.0-cm R at 20x, the coma was well seen and showed a nearly stellar central condensation of mag. 7.5 [TK]. There was a clear colour contrast between the yellow-orange reference stars 49 Vir and 50 Vir and the blue-green coma. Formal obs. at alt. 10° and solar alt. -12°. The inner coma remained visible until a solar altitude of -8.1°. Sky was clear. 2013 11 17.22 M 5.7 TK 5.0B 10 4 6 GRA Røverkollen, Oslo (In 10x50B, comet clearly seen but its visibility was much inferiour to C/2013 R1 due to a low altitude [9°] and a quite bright sky [moonlight and solar alt. -14°].) 2013 11 16.83 I 5.8 TJ 7.0R 10 9 YOS Mt. Tsukuba, Ibaraki 2013 11 16.82 M 6.3 TJ 40.0L 36 8 YOS Mt. Tsukuba, Ibaraki (Extremely strongly condensed. Quite different from one week ago! But hard to see the coma and tail due to the low sky haze. It was located near by Spica and easy to find.) 2013 11 16.73 M 6.2 TK 7.0B 11 4 5/ WYA Walcha, NSW (Moonlight and Twilight affected. Coma appears circular and slightly elongated to WSW [p.a. 290 deg.] showing a small and sometimes stellar central condensation. Tail is not obvious and hard to detect. Low altitude: 7.8°. Observed using 7x50B as well. I lost sight of the coma at around 5:05am AEDST [16.75 UT] in deep twilight.) 2013 11 16.22 5.3 8.0B 20 9 BAR Milan 2013 11 15.31 aI 4.8 TK 0.0E 1 9 GOI Araçatuba 2013 11 15.31 aB 4.8 TK 5.0B 7 6 7/ 1 290 GOI Araçatuba (Comet altitude: 14°. Nautical twilight.) 2013 11 14.71 M 5.3 TK 5.0B 7 8 WYA Walcha, NSW (Faint tail 30 in length in p.a. 295 deg. approximately. Very bright stellar central condensation with very faint outer coma. Enhances very strongly in Swan Band filter. Visible naked eye at 14.72 UT although very faintly and difficult to get estimate. It appeared stellar. Low altitude 5%deg; for binocular obs, and 7.6° when naked eye. Twilight interfered not long after. I lost visual sighting of comet through the binoculars at 14.74 UT deep in twilight.) 2013 11 14.22 M 6.1 TK 5.0B 10 3 8 0.7 300 GON Cueto Rosales - Riello, León 2013 11 14.21 M 6.3 TK 10.0B 25 2.5 8 0.7 300 GON Cueto Rosales - Riello, León (In outburst. Near-stellar appearance. Low altitude [15°] and zodiacal light interference didn't allow for making a naked eye observation and estimate. Mountain location, very clear sky.) 2013 11 13.75 S 8.0 TK 15.0B 25 2 6 MAT Swan Hill, VIC (8° altitude. Twilight interference. DC has increased considerably since last observation but coma still appears quite small.) 2013 11 13.74 S 7 : AA 10.0B 25 SEA Cowra, NSW (Enhanced through Swan Band filter.) 2013 11 13.72 M 7.4 TK 7.0B 11 6 6 WYA Walcha, NSW (Very faint tail 15 in length in p.a. 290 deg. Stellar central condensation, outer coma small with faint diffused edges. Low altitude 7.5°. Twilight.) 2013 11 13.31 M 7.2 TK 10.0B 20 4 7 0.5 300 GOI Araçatuba (Comet altitude: 16°. Nautical twilight.) 2013 11 13.22 8.1 8.0B 20 3 BAR Milan 2013 11 13.211 S 7.5 TK 10.0B 14 3 6 LOO Genk 2013 11 13.21 S 7.0 TK 5.0B 10 7 5/ SCH Eerbeek (In 20.0-cm L at 42x, tail 0.4 deg. in p.a. 295 deg. Aaltitude 16°.) 2013 11 13.20 M 7.7 TK 5.0B 10 4 6 GRA Røverkollen, Oslo 2013 11 13.20 M 7.7 TK 8.0R 20 4 6/ 0.4 295 GRA Røverkollen, Oslo (With 8.0-cm R at 20x, coma was easily seen and appeared compact and well-condensed. An apparently stellar nucleus was seen at the centre. Tail was narrow and quite faint. Comet also clearly seen in 10x50B. Clear and transparent sky. Comet observed at altitude 13° and solar altitude -17°. 2013 11 13.187 S 7.9 TK 8.0B 15 5 8 0.8 300 DIJ Burlage 2013 11 12.72 M 8.4 TK 7.0B 11 4 6 WYA Walcha, NSW (Coma small with compact central condensation and thin faint outer edge of coma. Appears circular, no tail. Twilight, low alt. 9°.) 2013 11 12.72 M 8.3 TK 25.0L 39 2.5 5 WYA Walcha, NSW (Tail to West approximately, difficult to determine length due to bright star. Enhances well in Swan Band filter. Low alt. 7.5°. Slight twilight interference, rapid movement noticeable over 10 minute period.) 2013 11 11.30 M 7.8 TK 10.0B 20 4 7 0.2 290 GOI Araçatuba (Comet altitude: 14°.) 2013 11 11.23 M 7.7 TK 5.0B 10 5 7 1.2 300 GON Sierra de Nuestra Señora - Castrocontrigo, León 2013 11 11.22 M 8.0 TK 10.0B 25 4 6/ 1.2 300 GON Sierra de Nuestra Señora - Castrocontrigo, León (Outer coma not perceptible. Another fainter tail was observable along 0.6-deg. in p.a. 285 deg. Zodiacal light interference. Altitude: 21°.) 2013 11 11.21 S 7.9 TK 8.0B 15 & 4 6 SCH Eerbeek (In 20.0-cm L at 42x, tail 0.3 deg. in p.a. 300 deg. Altitude 20°.) 2013 11 11.209 S 8.1 TK 10.0B 14 3 7 LOO Wouwberg, Peer 2013 11 11.20 M 8.0 TK 8.0R 30 4 6 GRA Røverkollen, Oslo (Comet easily seen. It appeared much brighter and more condensed when last seen four weeks ago. Tail suspected towards west. C/2012 S1 was also faintly visible in 10x50B. Observation made at altitude 16° and solar altitude -17°.) 2013 11 11.190 M 8.1 TK 8.0B 15 3.5 5/ 0.5 295 BOU Burlage, Germany (Nice, well condensed object with fairly obvious dusttail.) 2013 11 11.187 S 8.4 TK 8.0B 15 6 5 0.8 289 DIJ Burlage 2013 11 9.31 S 8.4 TK 10.0B 20 3 6 GOI Araçatuba (Nautical twilight. Comet altitude: 18°.) 2013 11 9.12 M 7.8 TT 5.0B 10 6 6 0.6 290 GUZ Czuszów (Easily seen, as small condensed objest, with obvious tail.) 2013 11 8.83 M 8.4 TJ 40.0L 75 3.4 7 0.15 290 YOS Mt. Tsukuba, Ibaraki (It looks very cool with a long tail.) 2013 11 8.79 S 8.3 TJ 40.0L 36 2.8 7 YOS Mt. Tsukuba, Ibaraki 2013 11 7.72 M 8.4 TK 7.0B 11 9 4 WYA Walcha, NSW (No tail. Coma appears diffuse with a small faint central condensation but not stellar. Low altitude: 10.6°. Slight twilight interference.) 2013 11 6.21 S 8.0 TK 5.0B 10 6 6 GON Collada del Fresno - Sierra del Aramo, Asturias 2013 11 6.20 S 8.3 TK 10.0B 25 5 6 0.6 300 GON Collada del Fresno - Sierra del Aramo, Asturias (The comet shows a clearly higher degree of condensation in comparison with my previous observation. Zodiacal light interference. Altitude: 23°.) 2013 11 5.72 S 8.6 TK 7.0B 11 6.5 2/ WYA Walcha, NSW (Coma enhances well using Swan Band filter and appears elongated to the West. No tail visible. Slight twilight interference. Low altitude at 11°.) 2013 11 5.156 S 8.4 TK 8.0B 15 8 4 DIJ Burlage 2013 11 4.74 S 8.4 AA 25.4L 71 & 4 SEA Cowra, NSW (Quite strongly enhanced thro Swan band filter. Low elevation & twilight.) 2013 11 4.73 S 8.7 TK 7.0B 11 5.3 2/ WYA Walcha, NSW (Coma diffuse. Small hint of central condensation, no tail. Windy conditions. Slight twilight interference, low alt. 12°.) 2013 11 4.72 M 9.1 TA 25.0L 39 3.5 5 WYA Walcha, NSW (Faint tail visible, 15.5 in length in p.a. 293 deg. Small compact coma, almost stellar. Low alt. at 10.5°.) 2013 11 4.12 M 8.6 TT 5.0B 10 5 4 0.3 290 GUZ Biórków Mały (I was a bit surprised that it was relatively obvious in 10x50B. I noticed it immediately after turning binoculars to nearby τ Leo, without any additional starhopping. It was at least as obvious as located higher M66 galaxy. The comet was additionally immersed in brighter portion of zodiacal light than M66.) 2013 11 3.75 S 9.0:TK 10.0B 25 3 3 MAT Swan Hill, VIC (8° altitude. Twilight interference.) 2013 11 2.71 M 9.5 TA 25.0L 39 3 5/ WYA Walcha, NSW (Faint tail visible, 12 in length in p.a. 290 deg. Enhances well using Swan Band filter. Inner coma bright with small central condensation. Low alt. at 9.3°.) 2013 11 2.32 S 9.2 TK 22.0L 60 3 3 GOI Araçatuba 2013 11 1.12 M 8.9 TT 5.0B 10 5 4 0.2 290 GUZ Przełęcz Szklarska (Relatively easy to see, but still pretty faint in binoculars.) 2013 11 1.12 M 9.2 TT 32.6L 50 3.5 4 0.3 290 GUZ Przełęcz Szklarska (Bright and large. Bright central core surrounded by much fainter halo. Long tail relatively easy to see.) 2013 10 31.72 M 9.6 TK 25.0L 39 4.4 5/ WYA Walcha, NSW (Very faint tail visible, 8 in length in p.a. 295 deg. Diffuse outer coma with small and slightly brighter central condensation, almost stellar in appearance. Coma enhances well in Swan Band filter, low alt. 9°.) 2013 10 31.20 S 8.3 TK 5.0B 10 6 3 GON Alto del Castro - Aralla, León 2013 10 31.19 S 8.5 TK 10.0B 25 6 3/ 0.4 300 GON Alto del Castro - Aralla, León 2013 10 31.18 S 8.8 TK 20.3T 77 5 4 0.4 300 GON Alto del Castro - Aralla, León (Slight moonlight interference. Faint outer coma was not perceptible.) 2013 10 31.165 S 9.4 TK 15.6L 29 3.5 4 BOU Sint Annen 2013 10 31.160 S 9.0 TK 8.0B 15 6.5 4 DIJ Burlage 2013 10 31.16 S 8.9 TK 20.0L 42 & 4 2 SCH Eerbeek (Comet at 21° altitude.) 2013 10 31.13 M 9.0 TT 5.0B 10 4 5 GUZ Przełęcz Szklarska (Faint, but definitely seen despite some moonlight interference.) 2013 10 31.13 M 9.3 TT 32.6L 50 3.5 4 0.25 300 GUZ Przełęcz Szklarska 2013 10 30.72 S 9.7 TK 25.0L 39 3.2 3 WYA Walcha, NSW (Coma diffuse with broad diffused centre. Close to bright star [magn. 7.3]. Moonlight, fog, low alt. 9°. No tail visible. Enhances using Swan Band filter.) 2013 10 30.140 S 9.3 TK 20.0L 48 2 4 LOO Wouwberg, Peer 2013 10 27.188 S 9.7 TK 8.0B 15 4 3/ DIJ Burlage (Moonlight.) 2013 10 27.16 S 10.0 TK 20.0L 80 & 4 2 SCH Eerbeek (Possibly underestimated due to moonlight.) 2013 10 23.13 M 9.8 TT 32.6L 50 3 4 GUZ Biórków Mały (Relatively easy too see despite bright moonlight. Elongated, rather bright inner coma immersed in fainter halo. Excellent transparency.) 2013 10 20.13 S 10.3:TT 20.3L 63 2 4 GUZ Krosno (Bright moonlight, some thin cirruses interference.) 2013 10 16.75 S 10.1 AQ 25.0L 39 3.9 2/ WYA Walcha, NSW (No tail. Coma appears broadly diffuse with slightly brighter central condensation. Enhances using Swan Band filter. Slight twilight interference. Observed at 12° altitude.) 2013 10 16.20 S 8.8 TK 10.0B 25 6 3/ GON Cubiellos - Sierra del Aramo, Asturias 2013 10 16.19 S 9.2 TK 20.3T 77 6 3/ 0.3 300 GON Cubiellos - Sierra del Aramo, Asturias (Zodiacal light.) 2013 10 14.75 S 10.2 AQ 25.0L 39 4 2/ WYA Walcha, NSW (No tail, coma appears elongated to the West approximately. Enhances slightly using Swan Band filter. Twilight interference, low altitude at 12.5°.) 2013 10 13.78 S 10.7 TJ 40.0L 75 2.5 3 YOS Kita-karuizawa, Gunma (I felt the comet became diffuse and weakly condensed.) 2013 10 13.13 S 10.5 TK 10.0R 40 2.5 3 GRA Breisjøen, Oslo (Challenging object but seen at the correct location, it was clearly harder to see than 2P and C/2013 R1. Some light pollution, otherwise favourable conditions. SQM-L reading 20.2.) 2013 10 12.78 S 9.9 TJ 40.0L 75 3.1 5 YOS Kita-karuizawa, Gunma (I felt somewhat elongated. It was well condensed.) 2013 10 12.78 S 10.8:TK 20.0L 57 2 2 MAT Swan Hill, VIC (Comet at limit of visibility. Twilight interference, 10° altitude.) 2013 10 11.78 S 10.4 TJ 40.0L 75 2.2 4 YOS Kita-karuizawa, Gunma (My first observation of Comet ISON. Already very bright. I felt somewhat elongated.) 2013 10 11.32 S 10.3 TK 22.0L 160 2 4 GOI Araçatuba (Nautical twilight, comet altitude 18°.) 2013 10 10.115 S 10.7 TA 15.5L 42 3.2 3 DIJ Burlage 2013 10 9.74 S 10.1 TA 25.0L 39 2.5 2 WYA Walcha, NSW (Bright star in coma [magn. 12.4]. Coma appears elongated to the North West approximately. Enhances slightly using Swan Band filter. No tail, 8.5° altitude. Slight twilight interference.) 2013 10 8.78 I[11.0 20.0L 57 ! 0 MAT Swan Hill, VIC (Comet not visible in brightening twilight at 8° altitude.) 2013 10 7.21 S 9.8 TK 10.0B 25 3 4 GON Alto del Castro - Aralla, León 2013 10 7.20 S 10.2 TK 20.3T 77 4 3/ 0.15 300 GON Alto del Castro - Aralla, León (Zodiacal light.) 2013 10 4.75 S 11.3 AQ 25.0L 39 2 2/ WYA Walcha, NSW (Coma close to bright star of magn. 10.6. Enhances slightly using Swan Band filter at 39x, at 83x the coma does not seem to enhance. No tail. Low alt, 9°.) 2013 10 4.11 M 10.9 AQ 32.6L 50 2.5 5 0.06 290 GUZ Dosłońce (Bright and relatively easy to see. Zodiacal light interference.) 2013 10 3.75 S 10.9 TA 25.0L 39 2.4 2/ WYA Walcha, NSW (Coma diffuse, with slight central condensation visible. Enhances moderately using Swan Band filter. No obvious tail. Low alt, 9°. Slight twilight interference, nearby stars appeared a little bloated due to atmospherics.) 2013 10 1.122 S 11.1 AQ 30.5T 73 2.5 4/ DIJ Burlage 2013 10 1.119 S 11.2 AQ 30.5T 73 2 5 BOU Burlage, Germany (Well condensed, somewhat elongated object, only 9 degrees from 15% illuminated Moon.) 2013 9 13.19 S 10.8 TK 20.3T 133 2.5 2/ GON Alto del Castro - Aralla, León (Faint outer coma, elongated inner coma. Altitude 21°. Nearby field stars checked in DSS. Mountain location, very clear sky and good seeing conditions.) 2013 9 8.08 M 12.7 AQ 32.6L 182 1 5 GUZ Dosłońce (Small, elongated object. Zodiacal light interference. Altitude 12°, comparison stars at the same low altitude.) 2013 9 6.13 S 11.9:AQ 35.6T 140 1.5 2 SCH Bussloo 2013 9 6.08 M 12.9 AQ 32.6L 182 0.8 5 GUZ Porąbka, Limanowa (Small, slightly elongated object. Altitude 12°, solar altitude -19°. Comparison stars at the same low altitude.) 2013 9 4.09 M 13.0 AQ 32.6L 182 0.8 5 GUZ Dosłońce (Small, slightly elongated object. Zodiacal light interference. Altitude 12°, solar altitude: -17°. Comparison stars at the same low altitude.) 2013 9 1.17 S 11.2 TK 20.3T 133 1.8 2/ GON Alto del Castro - Aralla, León (Significantly brighter than expected. Observed for 25 minutes. From dark mountain skies is possible to observe some extension of the faint outer coma, under very clear sky and good seeing conditions. Field stars checked in DSS, visible down to magnitude 13.9 [AQ] near comet. Altitude 14°. Slight moonlight interference.) 2013 8 31.10 S 13.2 AQ 32.6L 182 0.8 5 GUZ Czuszów (Small, slightly elongated object. Some moonlight and twilight interference. Altitude 13°, solar altitude -14°. Stars down to magn. ~14.0 [AQ] visible.) 2013 4 13.84 S 15.2:AQ 32.6L 182 0.3 3 GUZ Dosłońce (Barely visible. DSS field stars checked with DSS. Faintest stars seen in comet's vicinity were 15.7 mag [AQ].) 2013 1 13.90 I 14.8 AQ 20.3T 222 0.3 7 GON Alto de la Garandilla - Escuredo, León (Motion observed over a 70-min period. Field stars checked in DSS, visible down to magnitude 15.2 [AQ] near comet. Mountain location, very clear sky.)