C/2015 ER61 (PANSTARRS)

C/2015 ER61 (PANSTARRS)
Reported observations:
2017 Aug. 19.72 UT: m1=12.5, Dia.=1.5’, DC=2, ... 25-cm L f:5 (83x) ... Chris Wyatt (Walcha, NSW, Australia) [Coma diffuse, on edge of Pleaides star cluster, close to star but distinguishable. Comparison stars checked using APASS data in Guide 9.0; Method= S; Cat= AQ]
2017 Aug. 17.69 UT: m1=12.1, Dia.=1.2’, DC=2, ... 25-cm L f:5 (83x) ... Chris Wyatt (Walcha, NSW, Australia) [Coma very diffuse. Comet on edge of Pleiades star cluster. Low altitude = 12.1°. Comparison stars checked using APASS data in Guide 9.0; Method= S; Cat= AQ]
2017 Aug. 17.02 UT: m1=10.2, Dia.=3.5', DC=2/, ... 20-cm SCT (77x) ... (Alto del Castro - Aralla, Leon, Spain; Alt. 1720 m, 42º 54' N, 5º 48' W) [Before moonrise. Altitude: 17 deg. Sidgwick method. Tycho-2 comparison stars. SQM: 21.1]
2017 Aug. 12.77 UT: m1=10.7, Dia.=1.5', DC=3/, ... 40.0-cm L f/4.5 (144x) ... Seiichi Yoshida (Gunma, Japan) [Fading. Hard to see in the moon light. Near by Pleiades]
2017 Aug. 01.75 UT: m1=11.6, Dia.=3.8’, DC=4, ... 25-cm L f:5 (39x) ... (Chris Wyatt, Walcha, NSW, Australia) [Coma diffuse, brightening to centre, moderately condensed, does not enhance in Swan Band filter. Comparison stars checked using APASS data in Guide 9.0; Method= M; Cat= AQ]
2017 July 30.10 UT: m1=11.7, Dia=2.5', DC=2, no tail, ... 20-cm SCT (80x) ... Carlos Labordena (Castellón, España)
2017 July 25.78 UT: m1=11.2, Dia.=3’, DC=3/4, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Coma enhances slightly in Swan Band filter. Comparison stars checked using APASS data in Guide 9.0; Method= M; Cat= AQ]
2017 July 24.77 UT: m1=11.2, Dia.=2.8’, DC=3, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Coma enhances in Swan Band filter. Comparison stars checked using APASS data in Guide 9.0; Method= S; Cat= AQ]
2017 July 23.12 UT: m1=10.0, Dia.=3.5', DC=3/, ... 20-cm SCT (100x) ... Juan Jose Gonzalez (Alto del Castro - Aralla, Leon, Spain; Alt. 1720 m, 42º 54' N, 5º 48' W) [Sidgwick method. Tycho-2 comparison stars. SQM: 21.1]
2017 July 05.80 UT: m1=9.6, Dia.=5.6’, DC=6, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Faint tail visible, 20’ in length in P.A. 258°. Inner coma elongated and opaque. Small stellar central condensation. Fragment B not visible. Combined light observation. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 July 02.10 UT: m1=9.5, Dia.=4', DC=4, ... 20-cm SCT (77x) ... Juan Jose Gonzalez (Alto del Castro - Aralla, Leon, Spain; Alt. 1720 m, 42º 54' N, 5º 48' W) [Sidgwick method. Tycho-2 comparison stars. SQM: 21.0]
2017 June 30.75 UT: m1=9.7, Dia.=4.4’, DC=5, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Faint tail visible, traced to 20’ in length in P.A. 253°. Inner coma elongated in tail direction. Combined light from fragment B in coma although fragment B not visible. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 June 27.04 UT: m1=[8.7, NEGATIVE, Dia.=5', ... 20x80 B ... Marek Biely (244 m.a.s.l., Brno, Czech Republic) [Still too low to be seen. Fainter than 8.7 mag.]
2017 June 24.33 UT: m1=8.9, Dia.=4', DC=3/, ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 June 24.10 UT: m1=8.5, Dia=3', DC=3, no tail, ... 8cm B (11x) ... Carlos Labordena (Castellón, España)
2017 June 22.76 UT: m1=9.3, Dia.=4.1’, DC=5, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Faint tail visible, 10.5’ in length in P.A. 260°; Coma dims slightly in Swan Band filter. Inner coma appears elongated to the South-West approximately, Fragment B just noticeable as a diffuse smudge behind the central condensation in the coma. Magnitude refers to total combined light of the pair. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 June 21.10 UT: m1=8.0, Dia.=4', DC=4, ... 25x100 B ... Juan Jose Gonzalez (Puerto de Aralla, Leon, Spain; Alt. 1530 m, 42º 54' N, 5º 48' W) [Altitude: 14 deg. In 20 cm SCT(77x): m1=8.2, Dia.=3', DC=4/, Tail: 0.2 deg. in PA 260 deg. Sidgwick method. Tycho-2 comparison stars. SQM: 21.0]
2017 June 02.32 UT: m1=8.5:, ... 10-cm R (34x) ... Willian Souza (Sao Paulo, Brazil)
2017 May  26.32 UT: m1=8.0, Dia.=5', DC=5, ... 8-cm R (26x) ... Willian Souza (Sao Paulo, Brazil)
2017 May  24.12 UT: m1=7.9, Dia.=4', DC=5, ... 25x100 B ... Juan Jose Gonzalez (Puerto de Aralla, Leon, Spain; Alt. 1530 m, 42º 54' N, 5º 48' W) [In 20 cm SCT(77x): tail 0.4-deg in PA 260 deg. Beginning of astronomical twilight. Sidgwick method. Tycho-2 comparison stars. Altitude: 9 deg. SQM: 20.8. Mountain  location, very clear sky]
2017 May  08.30 UT: m1=7.7, Dia.=5', DC=5, ... 15x70 B ... Willian Souza (Sao Paulo, Brazil)
2017 May  07.76 UT: m1=7.9, Dia.=6.0', Tail= 0.2 degrees PA= 255 deg., ... 25x100 B .... David A. J. Seargent (Cowra, NSW, Australia) [Marginally enhanced using Swan Band filter]
2017 May  07.35 UT: m1=7.6, Dia.=6', DC=4/, ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil) [Haze]
2017 May  06.77 UT: m1=7.8, Dia.=8.5’, DC=6, ... 7x50 B ... Chris Wyatt (Walcha, NSW, Australia) [Star-like central condensation surrounded by a diffuse haze, appears clircular. Strongly enhances in Swan Band filter. Slight interference from zodiacal light and glare from Venus. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 May  06.21 UT: m1=7.9, Dia.=4', DC=5, no tail, ... 8-cm B (11x) ... Carlos Labordena (Castellón, España)
2017 May  04.75 UT: m1=7.8, Dia.=5', DC=5, ... 40.0-cm L f/4.5 (36x) ... Seiichi Yoshida (Gunma, Japan)
2017 May  03.15 UT: m1=7.5, Dia.=5', DC=5, ... 25x100 B ... Juan Jose Gonzalez (Puerto de Aralla, Leon, Spain; Alt. 1530 m, 42º 54' N, 5º 48' W) [In 20 cm SCT(77x): tail 0.6-deg in PA: 250 deg. Beginning of astronomical twilight. Sidgwick method. Tycho-2 comparison stars. Altitude: 9 deg. SQM: 21.5 at zenith. Mountain  location, very clear sky]
2017 Apr. 30.31 UT: m1=7.4, Dia.=6', DC=5, ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 Apr. 28.77 UT: m1=7.8, Dia.=8.2’, DC=6, ... 7x50 B ... Chris Wyatt (Walcha, NSW, Australia) [Coma diffuse, stellar centre enhances strongly in Swan Band filter. Tail visible, in 10”f/5 dob at x39, and traced to 23.5’ in length in P.A. 253°. Slight interference by zodiacal light. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 Apr. 28.16 UT: m1=7.4, Dia.=5', DC=5, ... 10x50 B ... Juan Jose Gonzalez (Puerto de Aralla, Leon, Spain; Alt. 1530 m, 42º 54' N, 5º 48' W)  [In 20 cm SCT(77x): tail 0.5-deg in PA: 250 deg. Beginning of astronomical twilight. Sidgwick method. Tycho-2 comparison stars. Altitude: 10 deg. SQM: 21.4 at zenith. Mountain  location, very clear sky]
2017 Apr. 26.33 UT: m=7.6, Dia.=6', DC=5, ... 15x70B ... Willian Souza (Sao Paulo, Brazil)
2017 Apr. 25.09 UT: m1=7.7, Dia.=8', DC=3, ... 25x100 B ... Martin Lehky (Czech Republic) [Morris Method]
2017 Apr. 24.17 UT: m1=7.4, Dia=4', DC=5, no tail, ... 8-cm B (11x) ... Carlos Labordena (Castellón, España)
2017 Apr. 22.29 UT: m1=7.5, Dia.= 5', DC=4, ... 9.0-cm-R f/5.5 (33x) ... Willian Souza (Sao Paulo, Brazil)
2017 Apr. 22.29 UT: m1=7.4, Dia.=4', DC=5, ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil) [Moonlight / clouds]
2017 Apr. 21.17 UT: m1=7.0, Dia.=5', DC=5, ... 25x100 B ... Juan Jose Gonzalez (Puerto de Aralla, Leon, Spain; Alt. 1530 m,  42º 54' N, 5º 48' W) [Astronomical twilight. Moonlight interference. Sidgwick method. Tycho-2 comparison stars. Altitude: 12 deg. SQM: 21.0 at zenith. Mountain  location, very clear sky]
2017 Apr. 19.34 UT: m=7.1, Dia.=8', DC=4, ... 15x70 B ... Willian Souza (Sao Paulo, Brazil)
2017 Apr. 16.27 UT: m1=6.9, Dia.=7', DC=4/, ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil) [Moonlight / clouds]
2017 Apr. 15.25 UT: m1=6.7, Dia.= 8', DC=4, ... 7x50 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil) [Moonlight / comet altitude: 11º]
2017 Apr. 10.34 UT: m1=6.5, Dia.=12', DC=4/, ... 7x50 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil) [Moonlight / clouds]
2017 Abr. 08.36 UT: m1=6.2, Dia.=12´, DC=6/, ... 25-cm f/4.5 L (66X) ... Gonzalo Vargas (Cochabamba, Bolivia) [Cola= 0.22 grados PA: 264 grados; con 66 aumentos y un filtro SkyGlow pude apreciar la fina cola que es más brillante cerca del borde de la coma del cometa]
2017 Apr. 08.19 UT: m1=6.5, Dia.=25', DC=3, ... 20x80 B ... J. P. Navarro Pina / Manuel Hernandez (Puerto Cadena, Murcia, Spain) [Comet very condensed and bright , altitude 400 mts]
2017 Apr. 07.18 UT: m1=6.2, Dia.=8', DC=5/, ... 10x50 B ... Juan Jose Gonzalez (Puerto de Aralla, Leon, Spain; Alt. 1530 m,  42º 54' N, 5º 48' W) [In evolution after the recent outburst. The comet shows a wider coma diameter and brighter m1 estimate in comparison with my previous Apr. 4.17 observation. Sidgwick method. Tycho-2 comparison stars. Altitude: 12 deg. SQM: 21.4 at zenith. Mountain  location, very clear sky]
2017 Apr. 07.18 UT: m1=7.1, Dia.=4', DC=6, no tail, ... 8-cm B(11x) ... Carlos Labordena (Castellón, España)
2017 Apr. 05.80 UT: m1=6.2, Dia.=8’, DC=5, ... 8x40 B ... Michael Mattiazzo (Swan Hill, Vic, Australia) [Clearly in outburst, 2 orders of magnitude brighter than 48 hours ago. Through 25x100mm binoculars, coma appears evenly bright and an ion tail at least 30’ long in PA 255 has developed]
2017 Apr. 05.74 UT: m1=6.4, Dia.=7.3’, DC=6/7, ... 7x50 B ... Chris Wyatt (Walcha, NSW, Australia) [In outburst; Inner coma bright and aqua-blue in colour, enhances strongly in Swan Band filter. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 Apr. 05.35 UT: m1=6.2, Dia.=7', DC=6/, Tail= 0.7º PA: 255 deg., ... 7x50 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 Apr. 05.34 UT: m1=6.4, Dia.=6', DC=7, Tail= 0.7º PA: 255 deg., ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 Abr. 05.33 UT: m1=6.4, Dia.=10´, DC=6, ... 25-cm f/4.5 L (66x) ... Gonzalo Vargas (Cochabamba, Bolivia) [Cola=0.3 grados en PA: 262 grados; con 132 aumentos pude apreciar cierto tipo de filamentos saliendo de la parte central en forma de abanico]
2017 Apr. 04.17 UT: m1=7.4, Dia.=4', DC=6, ... 10x50 B ... Juan Jose Gonzalez (Puerto de Aralla, Leon, Spain; Alt. 1530 m,  42º 54' N, 5º 48' W) [Possible outburst. The comet shows a higher DC, appearing significantly brighter than expected in comparison with my previous Apr. 1.18 observation. Sidgwick method. Tycho-2 comparison stars. SQM: 21.5 at zenith. Altitude: 9 deg. In 20 cm SCT(77x): m2=10.5: (Tycho-2). Dust tail 0.2-deg in PA 260 deg.  Mountain  location, very clear sky]
2017 Apr. 03.80 UT: m1=8.3, Dia.=5’, DC=4, ... 25x100 B ... Michael Mattiazzo (Swan Hill, Vic, Australia) [short dust tail 10’ in PA 255]
2017 Apr. 03.73 UT: m1=8.6, Dia.=4’, DC=6, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Faint tail traced to 29’ in length in P.A. 253° approximately; coma centre stellar and aqua-blue in colour. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 Apr. 02.28 UT: m1=8.4, Dia.=6', DC=5, Tail= 0.3º PA: 260 deg., ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 Apr. 02.18 UT: m1=8.8, Dia.=3.5', DC=4, no tail, ... 20-cm SCT(50x) ... Carlos Labordena (Castellón, España)
2017 Apr. 02.10 UT: m1=[7.0, NEGATIVE, ... 20x80 B ... Marek Biely (Brno, Czech Republic, 244 m.a.s.l.) [Impossible to see in these altitudes. Fainter than 7.0 mag.]
2017 Apr. 01.85 UT: m1=8.3, Dia.=6', DC=5,... 10-cm f/4 L (20x) ... Andrew Pearce (Bailup, W. Australia) [tail observed in 20cm L, 16' long in PA 258 deg.  Comet seems to have faded a reasonable amount in 24 hrs, sky conditions the same between both mornings]
2017 Apr. 01.71 UT: m1=8.1, Dia.=6.8’, DC=4, ... 11x70 B ... Chris Wyatt (Walcha, NSW, Australia) [Diffuse coma, moderately condensed centre, enhances in Swan Band filter. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 Apr. 01.18 UT: m1=8.2, Dia.=6', DC=3, ... 25x100 B ... Juan Jose Gonzalez (Candanedo de Fenar, Leon, Spain; Alt. 1060 m, 42º 49' N, 5º 34' W) [Sidgwick method. Tycho-2 comparison stars. SQM: 21.4 at zenith. Altitude: 10 deg. Mountain location, very clear sky]
2017 Mar. 31.84 UT: m1=7.6 Dia.=10', DC=4, ... 10-cm f/4 L (20x) ... Andrew Pearce (Bailup, W. Australia) [tail observed in 20cm L, 35' long in PA 263 deg.]
2017 Mar. 30.33 UT: m1=8.5, Dia.=6', DC=5, Tail= 0.3º PA: 260 deg., ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 Mar. 29.33 UT: m1=8.5, Dia.=6', DC=5, Tail= 0.3º PA: 260 deg., ... 20x100 B ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 Mar. 28.19 UT: m1=8.7, Dia.=4', DC=3, ... 25x100 B ... Juan Jose Gonzalez (Collado del Fresno, Asturias, Spain; Alt. 1280 m, 43º 10' N, 5º  54' W) [Sidgwick method. Tycho-2 comparison stars. SQM: 21.5 at zenith. Altitude: 12 deg. In 20 cm SCT(77x): Dust tail 0.2-deg in p.a. 260 deg. Mountain location, very clear sky]
2017 Mar. 28.17 UT: m1=9.0, Dia.=3', DC=4, no tail, ... 20-cm SCT(50x) ... Carlos Labordena (Castellón, España)
2017 Mar. 27.71 UT: m1=9.0, Dia.=3.6’, DC=5, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Faint tail visible, approximately 16.5’ in length in P.A. 259°. Coma enhances in Swan Band filter. Inner coma opaque. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 Mar. 25.78 UT: m1=8.6, Dia.=5’, DC=4, ... 25x100 B ... Michael Mattiazzo (Swan Hill, Vic, Australia) 
2017 Mar. 25.33 UT: m1=9.5, Dia.=5', DC=4/, ... 22-cm L (60x) ... Marco Antonio Coelho Goiato (Araçatuba, Brazil) [enhanced image with Swan band filter]
2017 Mar. 24.84 UT: m1=8.9 Dia.=5.5', DC=4, ... 10-cm f/4 L (20x) ... Andrew Pearce (Bailup, W. Australia)
2017 Mar. 09.23 UT: m1=9.1, Dia.=5', DC=2, ... 25x100 B ... Juan Jose Gonzalez (Cea, Leon, Spain; Alt. 880 m, 42º 28' N, 5º  0' W) [Sidgwick method. Tycho-2 comparison stars. Altitude: 16 deg. Astronomical twilight. Rural dark sky location, clear sky. Mar. 9.22 : In 20 cm SCT (77x) : m1=9.3, elongated coma. SQM: 21.3 at zenith]
2017 Mar. 08.68 UT: m1=10.4, Dia.=2.3’, DC=4, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Faint tail visible, approximately 5’ in length in P.A. 272°. Comparison stars checked using Tycho-2 data in Guide 9.0; Method= M; Cat= TK]
2017 Mar. 06.69 UT: m1=10.0, Dia.=2.8’, DC=4, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Short faint tail visible, 5.4’ in length in P.A. 235°; transparent coma enhances in Swan Band filter. Slight interference by star in coma, approximately 1’ from the central condensation. Comparison stars checked using APASS data in Guide 9.0; Method= M; Cat= AQ]
2017 Mar. 03.80 UT: m1=10.7, Dia.=1.1', DC=3/, ... 40.0-cm L f/4.5 (144x) ...Seiichi Yoshida (Ibaraki, Japan)
2017 Feb. 28.31 UT: m1=11.3, Dia.=1', DC=3, ... 22-cm L (160x) ... Marco Antonio Coelho Goiato (Araçatuba, Brazil)
2017 Feb. 23.67 UT: m1=10.9, Dia.=3’, DC=4, ... 25-cm L f:5 (39x) ... Chris Wyatt (Walcha, NSW, Australia) [Faint tail visible, 3.6’ in length in P.A. 286° approximately. Coma enhances well in Swan Band filter. Comparison stars checked using APASS data in Guide 9.0; Method= M; Cat= AQ]
2017 Feb. 21.21 UT: m1=9.5, Dia.=4', DC=2, ... 20-cm SCT (77x) ... Juan Jose Gonzalez (Alto de la Camperona, Leon, Spain; Alt. 1600 m, 42º 51' N, 5º 12' W) [Sidgwick method. Tycho-2 comparison stars. Very faint and diffuse outer coma. Altitude: 14 deg. Field stars checked in DSS. Some moonlight interference. Mountain location, very clear sky]
2017 Feb. 20.67 UT: m1=11.0, Dia.=1.4’, DC=2/3, ... 25-cm L f:5 (83x) ... Chris Wyatt (Walcha, NSW, Australia) [Moonlight; Enhances slightly in Swan Band filter, opaque centre. Comparison stars checked using APASS data in Guide 9.0; Method= S; Cat= AQ]
2017 Feb. 17.68 UT: m1=11.0, Dia.=1.4’, DC=3 ... 25-cm L f:5 (83x) ... Chris Wyatt (Walcha, NSW, Australia) [Moonlight. Slightly enhances in Swan Band filter. Comparison stars checked using APASS data in Guide 9.0; Method= S; Cat= AQ]
2017 Feb. 06.81 UT: m1=11.4, Dia.=1.2', DC=3; 40.0-cm L f/4.5 (144x); Seiichi Yoshida (Ibaraki, Japan)
2017 Feb. 01.71 UT: m1=11.2, Dia.=2.5’, DC=5/; 25-cm L f:5 (39x); Chris Wyatt (Walcha, NSW, Australia) [Outer coma very diffuse, brightening to a moderately condensed inner coma with a sometimes stellar central condensation. Coma slightly elongated to the West. Comparison stars checked using APASS data in Guide 9.0; Method= M; Cat= AQ]
2017 Jan. 31.70 UT: m1=11.5, Dia.=1.2’, DC=5; 25-cm L f:5 (83x); Chris Wyatt (Walcha, NSW, Australia) [Outer coma diffuse, elongated to West approximately. Gradual brightening to a small and opaque but moderately condensed centre, faintly stellar in good seeing. [Comparison stars checked using APASS data in Guide 9.0; Method= M; Cat= AQ]
2017 Jan. 30.71 UT: m1=12.0, Dia.=1’, DC=4; 25-cm L f:5 (83x); Chris Wyatt (Walcha, NSW, Australia) [Coma appears slightly elongated to the West approximately, transparent outer coma brightening to a moderately condensed and opaque centre. Does not enhance in Swan Band filter. Bright star of mag 7.8 (Tycho-2) 2.1’ away in P.A. 146°. Comparison stars checked using APASS data in Guide 9.0; Method= M; Cat= AQ]
2017 Jan. 29.70 UT: m1=12.0, Dia.=1.1’, DC=3/; 25-cm L f:5 (83x); Chris Wyatt (Walcha, NSW, Australia) [Outer coma diffuse and transparent, brightening slightly to centre. Coma slightly elongated to the West approximately. Does not enhance in Swan Band filter. Close to mag 12.2 star 0.2’ away in P.A. 0.3°. At x166 the inner coma appears small and opaque. Comparison stars checked using APASS data in Guide 9.0; Method= S; Cat= AQ]
2017 Jan. 28.18 UT: m1=11.4, Dia.=2′, DC=3... 33-cm L (67x)... Piotr Guzik (Koskowa Góra, Poland... Alt. 800 m, 49º 45′ N, 19º 47′ E) [Sidgwick method. APASS comparison stars. Low altitude: ~12 deg. Exceptional transparency, limiting stellar magnitude in comets vicinity ~15.0 mag. SQM: 20.9 at zenith]
2017 Jan. 24.83 UT: m1=12.2, Dia.=1.1′, DC=3/... 40.0-cm L f/4.5 (144x)... Seiichi Yoshida (Ibaraki, Japan)
2017 Jan. 24.22 UT: m1=9.3, Dia.=6′, DC=1... 20-cm SCT (77x)... Juan Jose Gonzalez (Collada de la Cobertoria, Asturias, Spain... Alt. 1190 m, 43º 09′ N, 5º 54′ W) [Sidgwick method. Tycho-2 comparison stars. SQM: 21.5 at zenith. Very faint and diffuse outer coma. Altitude: 13 deg. Field stars checked in DSS. Several stars in coma, the brightest being mag 12.5 (GSC). Mountain location, very clear sky]
2017 Jan. 23.69 UT: m1=12.5, Dia.=1’... DC=2/... 25-cm L f:5 (83x)... Chris Wyatt (Walcha, NSW, Australia) [Moonlight... Coma diffuse, slight brightening to centre. No enhancement in Swan Band filter. Motion detected after 15 mins. Comparison stars checked using APASS data in Guide 9.0... Method= S... Cat= AQ]
2017 Jan. 07.21 UT: m1=10.1, Dia.=4.5′, DC=1/... 20-cm SCT (77x)... Juan Jose Gonzalez (Alto del Castro, Leon, Spain... Alt. 1720 m, 42º 54′ N, 5º 48′ W) [Sidgwick method. Tycho-2 comparison stars. SQM: 21.5 at zenith. Very faint and diffuse outer coma. Altitude: 11 deg. Zodiacal light. Field stars checked in DSS. Mountain location, very clear sky]
2017 Jan. 01.25 UT: m1=10.2, Dia.=4.5′, DC=1/... 20-cm SCT (77x)... Juan Jose Gonzalez (Puerto de las Señales, Leon, Spain... Alt. 1610 m, 43º 05′ N, 5º 14′ W) [Sidgwick method. Tycho-2 comparison stars. SQM: 21.7 at zenith. Very faint and diffuse outer coma. Altitude: 17 deg. Zodiacal light. Field stars checked in DSS. Mountain location, very clear sky]
2016 Dec. 30.20 UT: m1=13.9, Dia.=0.6’, DC=4... 60-cm L (305x)... Sandor Szabo (Hungary)
2016 Dec. 29.72 UT: m1=13.0, Dia.=0.6’, DC=2/... 25-cm L f:5 (83x)... Chris Wyatt (Walcha, NSW, Australia) [Coma small and diffuse, difficult to see due to zodiacal light and twilight interference. Comparison stars checked using APASS data in Guide 9.0... Method= S... Cat= AQ]
2016 Dec. 29.22 UT: m1=13.3, Dia.=1.2′, DC=5... 35-cm L (178x)... Jakub Cerny (Senohraby, Czech Republic)
2016 Dec. 26.52 UT: m1=13.6, Dia.=0.7′, DC=5... 41-cm L (229x)... Alan Hale (Cloudcroft, USA) [The coma is somewhat “dense” but is not really “condensed.”]
2016 Dec. 26.25 UT: m1=11.2, Dia.=2.5′, DC=1/... 20-cm SCT (133x)... Juan José González (Les Retuertes – Sierra del Aramo, alt. 1350 m, Asturias, España... Alt. 1350 m, 43º 10′ N, 5º 54′ W) [Método Sidgwick. Estrellas de comparación Tycho-2. Muy débil y difusa coma externa. Altura sobre el horizonte: 16º. Alguna interferencia de la luz lunar. Estrellas de campo comprobadas en el DSS. Magnitud límite estelar en la zona del cometa: 13.9 (APASS). Cielo muy claro de montaña]
2016 Dec. 23.23 UT: m1=12.2, Dia=1′, DC=1, no tail... 20-cm SCT (118x)... Carlos Labordena (Castellón, España)
2016 Dec. 10.25 UT: m1=10.3, Dia.=3′, DC=1/... 20-cm SCT (100x)... Juan José González (Les Retuertes – Sierra del Aramo, alt. 1350 m, Asturias, España) [Muy débil y difusa coma externa. Altura sobre el horizonte: 14º. Estrellas de campo comprobadas en el DSS. Magnitud límite estelar en la zona del cometa: 13.5 (APASS) – 14.0 (GSC). Cielo muy claro de montaña]
2016 Dec. 06.25 UT: m1=10.4, Dia.=2.5′, DC=2... 20-m SCT (100x)... Juan José González (Les Retuertes – Sierra del Aramo, alt. 1350 m, Asturias, España ) [Débil y difusa coma externa. Altura sobre el horizonte : 13º. Estrellas de campo comprobadas en el DSS. Magnitud límite estelar en la zona del cometa : 13.5 (APASS). Cielo muy claro de montaña]