Weekly Information about Bright Comets (2021 Apr. 10: North)

Japanese version Home page	Updated on April 18, 2021
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Best time and the azimuth, altitude (A,h) are at lat. 35 deg in the Northern Hemisphere. Azimuth indicates 0 for south, 90 for west, 180 for north, 270 for east.

C/2020 R4 ( ATLAS ) It brightened rapidly in December. Now it is bright as 8.9 mag (Apr. 12, Carlos Labordena). It stays observable at 9 mag in excellent condition in April. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 19 5.93 6 38.8 0.671 1.216 91 8.9 4:07 (313, 52) Apr. 17 17 59.88 17 7.7 0.520 1.280 110 8.7 3:56 (341, 71) C/2020 T2 ( Palomar ) It brightened rapidly. Now it is very bright as 11.3 mag (Apr. 12, Carlos Labordena). It stays observable at 11 mag in good condition for a long time from spring to summer. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 13 59.35 34 24.2 1.495 2.326 136 11.7 0:48 ( 0, 89) Apr. 17 13 55.00 34 7.6 1.463 2.289 135 11.6 0:16 ( 0, 89) 10P/Tempel 2 Now it is 10.8 mag (Apr. 10, Chris Wyatt). Appearing in the morning sky in the Southern Hemisphere. In the Northern Hemisphere, it will appear in the morning sky in June. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 23 19.24 -8 21.8 2.157 1.424 32 11.6 4:07 (277, -5) Apr. 17 23 41.05 -6 44.2 2.150 1.435 34 11.7 3:56 (275, -5) C/2021 D1 ( SWAN ) It brightened up to 10.5 mag in early March (Mar. 8, Bob King). Now it is fading. But it is still bright as 12.6 mag (Apr. 4, Sandor Szabo). In the Northern Hemisphere, it stays observable in the evening low sky until early June while the comet will be fading. It is not observable in the Southern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 3 5.15 33 11.4 1.807 1.159 36 12.4 19:55 (119, 18) Apr. 17 3 42.98 34 5.3 1.884 1.236 36 12.8 20:03 (119, 19) C/2019 L3 ( ATLAS ) Now it is 13.0 mag (Mar. 31, Thomas Lehmann). It will brighten up to 10 mag in winter in 2022. In the Northern Hemisphere, it stays observable in good condition for a long time. In the Southern Hemisphere, it is not observable until November. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 2 36.54 50 59.5 4.954 4.324 46 12.9 19:55 (138, 22) Apr. 17 2 49.65 50 54.0 4.969 4.290 42 12.8 20:03 (140, 19) C/2019 N1 ( ATLAS ) It brightened up to 11.6 mag in winter (Feb. 18, Thomas Lehmann). Now it is fading. It has already faded down to 14.2 mag (Apr. 12, Chris Wyatt). In the Southern Hemisphere, it stays observable in good condition after this. In the Northern Hemisphere, it will never be observable after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 3 55.22 -65 9.9 2.350 2.370 78 13.0 19:55 ( 28,-27) Apr. 17 4 4.21 -62 26.0 2.431 2.429 77 13.2 20:03 ( 32,-28) C/2017 K2 ( PanSTARRS ) Now it is 13.9 mag (Apr. 12, Chris Wyatt). It is expected to be observable at 5-6 mag for a long time from 2022 to 2023. In the Northern Hemisphere, it is not observable at the high light from 2022 summer to 2023 summer. In the Southern Hemisphere, it stays extremely low for a while. But it will be observable in good condition at the high light. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 27.43 40 13.3 6.515 6.655 93 13.3 4:07 (244, 76) Apr. 17 18 26.11 40 51.0 6.405 6.598 96 13.2 3:56 (235, 79) C/2019 F1 ( ATLAS-Africano ) Now it is 14.8 mag (Apr. 12, Chris Wyatt). It is expected to brighten up to 13 mag from spring to summer. But actually, it is fainter than this ephemeris recently. In the Southern Hemisphere, it stays observable in good condition for a long time. In the Northern Hemisphere, it is not observable until July in 2022. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 19 28.46 -68 45.4 3.415 3.658 96 13.3 4:07 (348,-16) Apr. 17 19 45.44 -70 28.7 3.347 3.647 99 13.2 3:56 (349,-18) 7P/Pons-Winnecke Now it is 13.5 mag (Mar. 28, Thomas Lehmann). Brightenening very rapidly. It will brighten up to 11 mag from May to August. In the Southern Hemisphere, it stays observable in excellent condition for a long time. In the Northern Hemisphere, it stays observable in good condition for a while. But it becomes extremely low after July. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 19.41 8 15.9 0.734 1.362 102 13.9 4:07 (330, 60) Apr. 17 18 42.48 7 17.0 0.678 1.328 102 13.5 3:56 (328, 59) 246P/NEAT Now it is 15.1 mag (Apr. 12, Chris Wyatt). It stays 13-14 mag from 2020 to 2021. It will be observable in good condition after this in the Southern Hemisphere. It locates somewhat low in the Northern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 19 9.42 -24 35.0 2.621 2.875 94 13.8 4:07 (332, 25) Apr. 17 19 15.44 -24 59.4 2.532 2.878 99 13.8 3:56 (335, 26) C/2020 J1 ( SONEAR ) Now it is 13.2 mag (Apr. 12, Chris Wyatt). It stays 13.5 mag until early summer. In the Southern Hemisphere, it stays observable in good condition for a long time. It is getting higher slowly also in the Northern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 16 59.95 -37 51.9 2.728 3.356 121 13.9 3:48 ( 0, 17) Apr. 17 16 44.54 -36 56.9 2.613 3.355 130 13.8 3:06 ( 0, 18) 29P/Schwassmann-Wachmann 1 Now it is 13.2 mag (Mar. 6, Thomas Lehmann). It is already unobservable in the Southern Hemisphere. It will be unobservable soon also in the Northern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 3 1.76 25 29.4 6.706 5.871 31 13.9 19:55 (112, 13) Apr. 17 3 7.51 25 47.1 6.760 5.873 25 13.9 20:03 (116, 8) C/2020 K5 ( PanSTARRS ) It was expected to brighten up to 13 mag from spring to summer. But actually, now it is extremely faint as 19.0 mag (Mar. 22, A. C. Gilmore, P. M. Kilmartin). In the Southern Hemisphere, it stays observable in good condition for a long time. In the Northern Hemisphere, it is not observable until late August. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 21 54.29 -41 1.2 1.846 1.721 66 14.2 4:07 (315, -9) Apr. 17 22 27.70 -42 59.6 1.755 1.681 69 14.0 3:56 (314,-12) C/2021 A4 ( NEOWISE ) It brightening very rapidly up to 12.5 mag in early February (Feb. 8, Michael Jager). Now it is fading. It has already faded down to 14.9 mag (Apr. 12, Chris Wyatt). In the Southern Hemisphere, it stays observable after this while the comet will be fading. It is not observable after this in the Northern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 4 12.22 -10 10.3 1.605 1.192 47 14.1 19:55 ( 73, 6) Apr. 17 4 12.81 -12 4.7 1.730 1.227 44 14.7 20:03 ( 76, -1) C/2019 T4 ( ATLAS ) Now it is 14.1 mag (Apr. 12, Chris Wyatt). It is expected to brighten up to 11.5 mag in 2022. It is observable in excellent condition in the Southern Hemisphere. In the Northern Hemisphere, it is observable in the low sky until May. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 8 1.82 -32 17.2 5.140 5.473 104 14.3 19:55 ( 15, 21) Apr. 17 8 4.16 -31 13.0 5.166 5.439 100 14.3 20:03 ( 23, 20) 4P/Faye It has not been observed yet in this apparition. It will brighten up to 10 mag from summer to autumn, and it will be observable in excellent condition. It is appearing in the morning sky soon. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 22 49.82 -2 42.0 2.903 2.194 37 15.0 4:07 (276, 5) Apr. 17 23 4.15 -1 20.8 2.815 2.153 40 14.7 3:56 (276, 6) C/2019 T2 ( Lemmon ) It will brighten up to 14.5 mag from spring to summer. In the Southern Hemisphere, it stays observable in excellent condition for a long time. In the Northern Hemisphere, it is not observable after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 23 46.78 -48 43.5 3.009 2.649 59 15.0 4:07 (311,-30) Apr. 17 0 3.03 -50 43.1 2.917 2.647 64 15.0 3:56 (313,-30) C/2020 F5 ( MASTER ) Now it is 15.3 mag (Apr. 12, Chris Wyatt). It stays 14-15 mag until the end of 2021. In the Southern Hemisphere, it stays observable in good condition for a long time. In the Northern Hemisphere, it is not observable until June. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 23 2.84 -39 48.5 4.800 4.328 56 15.1 4:07 (306,-19) Apr. 17 23 9.56 -38 59.2 4.736 4.330 60 15.0 3:56 (306,-17) C/2018 U1 ( Lemmon ) Now it is 14.7 mag (Mar. 12, D. Buczynski). It will stay at 14-15 mag for a long time from 2021 to 2022. It stays observable in good condition after this while brightening gradually. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 19.11 1 33.2 4.916 5.240 103 15.2 4:07 (334, 54) Apr. 17 18 16.16 1 19.2 4.790 5.224 110 15.1 3:56 (342, 55) C/2020 S3 ( Erasmus ) It brightened up to 5.6 mag in early December (Dec. 9, Marco Goiato). In mid December, it was visible at about 3 mag in the SOHO spacecraft images (Dec. 18, Hirohisa Sato). It is appearing in the morning sky soon. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 23 26.10 9 44.4 3.165 2.315 26 15.1 4:07 (261, 4) Apr. 17 23 34.73 10 51.1 3.223 2.415 30 15.4 3:56 (261, 7) C/2021 A7 ( NEOWISE ) Now it is 15.6 mag (Apr. 12, Chris Wyatt). It stays 15 mag until summer. In the Southern Hemisphere, it stays observable in good condition until June. In the Northern Hemisphere, it is observable in the low sky from March to May. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 6 35.95 -27 46.9 2.139 2.287 85 15.2 19:55 ( 35, 18) Apr. 17 6 46.12 -23 33.9 2.152 2.246 82 15.2 20:03 ( 43, 18) 156P/Russell-LINEAR Brightened rapidly, and it brightened up to 9.7 mag in November (Nov. 15, Chris Wyatt). Now it is fading. It has already faded down to 14.9 mag (Apr. 4, Sandor Szabo). In the Northern Hemisphere, it stays observable in good condition for a long time. In the Southern Hemisphere, it locates extremely low after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 6 6.80 40 2.2 2.112 2.041 72 15.2 19:55 (112, 54) Apr. 17 6 25.63 39 29.6 2.227 2.091 69 15.5 20:03 (112, 51) 88P/Howell It brightened up to 8.2 mag in autumn (Oct. 13, Chris Wyatt). It faded down to 13.0 mag in February (Feb. 14, Sandor Szabo). It is not observable after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 1 49.21 9 54.0 3.331 2.346 8 15.2 19:55 (110,-10) Apr. 17 2 1.77 11 8.4 3.390 2.392 5 15.4 20:03 (115,-14) 117P/Helin-Roman-Alu 1 Now it is 15.2 mag (Mar. 24, F. Kugel, J.-G. Bosch). It will brighten up to 13 mag in 2022. In 2021, it is observable at 15-16 mag in good condition. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 13 24.71 -0 47.1 2.693 3.688 172 15.4 0:13 ( 0, 54) Apr. 17 13 19.98 -0 29.1 2.682 3.672 168 15.3 23:36 ( 0, 54) 17P/Holmes Now it is 15.8 mag (Jan. 16, Slooh.com Canary Islands Observatory). It is not observable until June. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 0 31.25 13 0.9 3.086 2.115 11 15.3 4:07 (249, -7) Apr. 17 0 45.47 15 1.4 3.085 2.125 14 15.4 3:56 (248, -5) C/2017 T2 ( PanSTARRS ) It had been observed as 8-9 mag for a long time in 2020. Now it is fading. It has already faded down to 16.4 mag (Mar. 27, Thomas Lehmann). It will be observable in good condition after this in the Southern Hemisphere. It locates extremely low after this in the Northern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 17 44.25 -40 0.0 3.837 4.317 112 15.4 4:07 (355, 15) Apr. 17 17 41.21 -41 1.2 3.805 4.381 119 15.5 3:56 (359, 14) C/2021 A2 ( NEOWISE ) It brightened up to 10.5 mag in early February (Feb. 6, Marco Goiato). Now it is fading rapidly. It has already faded down to 15.7 mag (Apr. 4, Sandor Szabo). In the Northern Hemisphere, it stays observable for a long time after this. In the Southern Heimsphere, it will never be observable again. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 5 1.98 51 0.8 1.990 1.786 63 15.5 19:55 (130, 44) Apr. 17 5 5.92 52 26.7 2.150 1.845 58 16.0 20:03 (133, 39) C/2019 K7 ( Smith ) Now it is 15.4 mag (Mar. 16, Toshihiko Ikemura, Hirohisa Sato). It stays 15-16 mag until spring. In the Northern Hemisphere, it stays observable in good condition for a long time. In the Southern Hemisphere, it will be observable in the extremely low sky only in next spring. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 19 19.39 42 32.2 5.083 5.073 83 15.7 4:07 (243, 66) Apr. 17 19 16.53 44 28.3 5.054 5.099 86 15.7 3:56 (236, 69) C/2020 M5 ( ATLAS ) Now it is 16.4 mag (Mar. 30, Thomas Lehmann). In the Northern Hemisphere, it stays observable at 15 mag for a long time from spring to early 2022. In the Southern Hemisphere, it is not observable until the end of 2021. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 20 13.70 66 13.4 3.352 3.273 76 15.9 4:07 (205, 50) Apr. 17 20 5.63 69 12.5 3.303 3.247 78 15.8 3:56 (200, 50) 28P/Neujmin 1 Now it is not observable. It will be observable in June. But it will fade down to 17 mag at that time. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 0 9.39 2 6.2 2.547 1.617 17 15.9 4:07 (261, -9) Apr. 17 0 27.23 4 46.9 2.554 1.637 18 16.0 3:56 (259, -7) C/2020 Y2 ( ATLAS ) Now it is 16.0 mag (Apr. 4, Michael Jager). It is expected to brighten up to 13 mag in 2022. In the Southern Hemisphere, it stays observable in good condition for a long time. In the Northern Hemisphere, it stays observable until June, but it will not be observable at the high light. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 13 17.36 -20 48.8 4.093 5.075 167 16.1 0:06 ( 0, 34) Apr. 17 13 8.62 -20 53.7 4.045 5.028 167 16.0 23:25 ( 0, 34) C/2020 M3 ( ATLAS ) It brightened up to 7.3 mag in November (Nov. 7, Marco Goiato). Now it is fading. It has already faded down to 16.0 mag (Mar. 17, Toshihiko Ikemura, Hirohisa Sato). In the Northern Hemisphere, it stays observable in excellent condition for a long time. In the Southern Hemisphere, it stays locating extremely low after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 7 22.73 43 52.1 2.457 2.590 86 16.2 19:55 (121, 68) Apr. 17 7 34.87 43 6.2 2.610 2.663 82 16.5 20:03 (118, 64) C/2018 N2 ( ASASSN ) Now it is 15.2 mag (Mar. 30, Thomas Lehmann). In the Northern Hemisphere, it stays observable for a long time while it is getting fainter slowly. In the Southern Hemisphere, it will never be observable again. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 15 30.52 69 37.3 5.390 5.635 99 16.2 2:18 (180, 55) Apr. 17 15 14.95 69 42.2 5.452 5.683 98 16.3 1:35 (180, 55) C/2020 N1 ( PanSTARRS ) Now it is 16.5 mag (Mar. 30, Thomas Lehmann). It will be fading after this. In the Northern Hemisphere, it will be getting lower gradually, and will be too low to observe in May. In the Southern Hemisphere, it stays observable in good condition after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 5 43.45 8 34.2 1.439 1.389 66 16.3 19:55 ( 73, 36) Apr. 17 6 7.61 6 30.9 1.493 1.424 66 16.5 20:03 ( 73, 33) C/2020 H6 ( ATLAS ) Now it is 15.7 mag (Apr. 4, Michael Jager). It stays observable at 16 mag from 2021 to 2022. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 14 12.16 -16 56.8 3.933 4.900 163 16.4 1:01 ( 0, 38) Apr. 17 14 7.72 -15 26.1 3.890 4.885 171 16.3 0:29 ( 0, 39) 409P/2020 V1 ( LONEOS-Hill ) First return of a new periodic comet which brightened up to 14-15 mag in 2006. Now it is 14.8 mag (Apr. 4, Sandor Szabo). It will be fading rapidly after this, and it will be fainter than 18 mag in May. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 13 18.63 21 16.9 0.981 1.919 150 16.3 0:07 ( 0, 76) Apr. 17 13 17.34 21 44.0 1.027 1.950 147 16.6 23:34 ( 0, 77) C/2020 S8 ( Lemmon ) Now it is 15.5 mag (Apr. 5, Sandor Szabo). It stays observable at 16 mag in good condition from April to May. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 15 6.10 15 10.9 1.479 2.364 143 16.5 1:55 ( 0, 70) Apr. 17 14 37.31 14 0.9 1.432 2.365 151 16.4 0:59 ( 0, 69) C/2017 Y2 ( PanSTARRS ) Now it is 16.7 mag (Mar. 14, Toshihiko Ikemura, Hirohisa Sato). It is observable at 16.5 mag from spring in 2020 to summer in 2021. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 17 34.11 -13 50.0 4.272 4.797 116 16.5 4:07 (355, 41) Apr. 17 17 27.81 -14 19.3 4.174 4.812 124 16.5 3:48 ( 0, 41) C/2019 T3 ( ATLAS ) Now it is 16.5 mag (Feb. 9, Toshihiko Ikemura, Hirohisa Sato). It is observable at 16 mag from 2020 to 2021. In the Southern Hemisphere, it is not observable until summer. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 23 9.17 42 38.3 6.628 5.953 44 16.5 4:07 (234, 25) Apr. 17 23 11.99 42 45.9 6.613 5.955 45 16.5 3:56 (235, 27) C/2020 O2 ( Amaral ) Now it is 16.5 mag (Feb. 11, Taras Prystavski). It will brighten up to 16.5 mag in summer. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 17 36.34 -31 27.6 4.479 4.984 114 16.7 4:07 (356, 23) Apr. 17 17 34.54 -30 41.7 4.365 4.972 122 16.7 3:55 ( 0, 24) C/2019 O3 ( Palomar ) Now it is 16.2 mag (Mar. 16, Toshihiko Ikemura, Hirohisa Sato). It stays at 16-17 mag from 2020 to 2021. In the Northern Hemisphere, it stays observable in good condition for a long time. It locates extremely low in the Southern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 19 47.41 40 41.3 8.965 8.822 78 16.7 4:07 (248, 61) Apr. 17 19 47.25 41 44.1 8.910 8.823 81 16.7 3:56 (245, 64) C/2019 U5 ( PanSTARRS ) Now it is 17.0 mag (Apr. 1, Michael Jager). It is expected to brighten up to 11 mag in 2023. In the Northern Hemisphere, it stays observable in good condition for a long time. It locates extremely low in the Southern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 30.53 45 17.2 6.907 7.013 91 16.9 4:07 (227, 73) Apr. 17 18 27.04 46 13.0 6.813 6.969 94 16.8 3:56 (217, 75) 413P/2020 W4 ( Larson ) First return of a new periodic comet which brightened up to 16 mag in 2014. Now it is 16.0 mag (Apr. 4, Sandor Szabo). It stays observable at 16-17 mag in good condition until July. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 12 27.33 12 14.3 1.317 2.272 156 16.9 23:11 ( 0, 67) Apr. 17 12 21.28 11 35.6 1.327 2.256 150 16.9 22:38 ( 0, 66) C/2020 V2 ( ZTF ) Now it is 17.0 mag (Apr. 11, Toshihiko Ikemura, Hirohisa Sato). It is expected to brighten up to 10 mag in 2023. In the Northern Hemisphere, it stays observable in good condition until 2023 autumn. In the Southern Hemipshere, it stays extremely low until mid July, then it becomes unobservable for a while. But it becomes observable in good condition after 2023 summer. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 12 39.74 37 51.2 6.826 7.552 133 17.0 23:24 (180, 87) Apr. 17 12 34.44 38 17.4 6.827 7.500 128 16.9 22:51 (180, 87) C/2017 U7 ( PanSTARRS ) Now it is 16.7 mag (Apr. 11, Toshihiko Ikemura, Hirohisa Sato). It will be fading slowly. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 22.04 -16 40.1 7.168 7.485 104 16.9 4:07 (341, 36) Apr. 17 18 19.15 -16 18.0 7.073 7.508 112 16.9 3:56 (347, 38) P/2020 U2 ( PanSTARRS ) Brightened very rapidly up to 15.0 mag (Feb. 4, Michael Jager). Now it is fading. It hasl already faded down to 17.8 mag (Apr. 11, Toshihiko Ikemura, Hirohisa Sato). It is observable in good condition in the Northern Hemisphere. It locates low in the Southern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 5 50.66 27 53.0 2.227 2.071 67 17.1 19:55 ( 95, 48) Apr. 17 6 7.20 27 35.1 2.320 2.098 64 17.3 20:03 ( 96, 44) 398P/2020 P2 ( Boattini ) First return of a new periodic comet which brightened up to 13 mag in 2009. It brightened up to 11.7 mag in January (Jan. 10, Marco Goiato). Now it is fading. It has already faded down to 16.9 mag (Mar. 29, Thomas Lehmann). It stays observable in good condition while the comet will be fading after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 8 32.04 27 16.2 1.201 1.733 103 17.2 19:55 ( 48, 79) Apr. 17 8 48.00 26 36.4 1.303 1.780 100 17.6 20:03 ( 59, 75) C/2021 A1 ( Leonard ) Now it is 17.4 mag (Mar. 18, Toshihiko Ikemura, Hirohisa Sato). It will approach to Earth down to 0.2 a.u. in December, and it is expected to brighten up to 4 mag. In the Northern Hemisphere, it stays observable in good condition for a long time until December while the comet is brightening gradually. In the Southern Hemisphere, it is not observable until mid December. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 12 26.01 61 29.5 3.598 4.052 110 17.4 23:09 (180, 64) Apr. 17 12 7.24 61 48.6 3.585 3.974 105 17.3 22:23 (180, 63) 417P/2021 B1 ( NEOWISE ) First return of a new periodic comet observed at 19 mag in 2015. Now it is 17.8 mag (Mar. 4, Giuseppe Pappa). It will brighten up to 17 mag in early summer, and it will be observable in good condition. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 11.90 -11 17.2 0.862 1.497 106 17.4 4:07 (343, 42) Apr. 17 18 28.55 -11 15.8 0.822 1.493 109 17.3 3:56 (343, 42) C/2020 F7 ( Lemmon ) Now it is 17.1 mag (Apr. 9, Toshihiko Ikemura, Hirohisa Sato). It brightened rapidly. It stays 17-18 mag for a long time from 2021 to 2022. In the Southern Hemisphere, it stays observable in good condition for a long time. In the Northern Hemisphere, it is observable only until May. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 8 20.62 -7 7.2 5.189 5.570 107 17.5 19:55 ( 18, 46) Apr. 17 8 18.37 -7 11.7 5.281 5.556 100 17.5 20:03 ( 30, 43) C/2021 C3 ( Catalina ) It brightened rapidly up to 16.3 mag in March (Mar. 16, F. Kugel, J.-G. Bosch). Now it is fading. It has already faded down to 18.0 mag (Apr. 11, Toshihiko Ikemura, Hirohisa Sato). It is observable in excellent condition in the Northern Hemisphere. It locates somewhat low in the Southern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 10 57.29 33 4.5 1.612 2.362 127 17.5 21:41 ( 0, 88) Apr. 17 10 40.13 36 3.0 1.752 2.384 117 17.7 20:56 (180, 89) C/2019 C1 ( ATLAS ) Now it is 17.3 mag (Apr. 4, Michael Jager). Fading slowly. In 2021, it stays observable at 17-18 mag in good condition until early summer. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 13 3.80 -17 3.1 5.967 6.957 170 17.5 23:48 ( 0, 38) Apr. 17 13 1.83 -16 28.1 5.984 6.972 168 17.5 23:19 ( 0, 38) C/2020 F2 ( ATLAS ) Now it is 17.1 mag (Apr. 11, Toshihiko Ikemura, Hirohisa Sato). It stays observable at 17-18 mag for a long time until 2024. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 15 17.58 -10 31.6 8.337 9.214 149 17.6 2:06 ( 0, 44) Apr. 17 15 13.42 -10 5.5 8.270 9.202 156 17.5 1:34 ( 0, 45) 277P/LINEAR It brightened rapidly and became brighter than expected. Now it is 16.9 mag (Mar. 18, Toshihiko Ikemura, Hirohisa Sato). It is observable in good condition in the Northern Hemisphere. It locates somewhat low in the Southern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 5 41.37 19 16.5 2.302 2.097 65 17.6 19:55 ( 85, 42) Apr. 17 5 56.37 18 48.6 2.394 2.123 62 17.7 20:03 ( 88, 37) 99P/Kowal 1 Now it is 17.4 mag (Mar. 14, Toshihiko Ikemura, Hirohisa Sato). It stays 17-18 mag for a long time from 2021 to 2023. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 10 39.40 12 18.5 4.127 4.903 136 17.6 21:24 ( 0, 67) Apr. 17 10 37.87 12 20.5 4.197 4.896 129 17.6 20:55 ( 0, 67) 98P/Takamizawa It has not been observed yet in this apparition. In the Southern Hemissphere, appearing in the morning sky. It is already fading. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 22 56.38 -10 40.5 2.577 1.905 38 17.7 4:07 (282, -1) Apr. 17 23 11.79 -9 34.0 2.566 1.938 41 17.9 3:56 (281, 0) 284P/McNaught It will brighten up to 15 mag from summer to autumn, and it will be observable in good condition. It already locates high in the Southern Hemisphere. It will be getting higher gradually also in the Northern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 21 20.34 -10 44.7 2.857 2.529 61 17.8 4:07 (297, 17) Apr. 17 21 31.67 -10 2.8 2.763 2.510 65 17.7 3:56 (297, 19) 15P/Finlay It has not been observed yet in this apparition. It will brighten very rapidly, and it will brighten up to 10 mag from July to August. It stays observable in the morning sky for a long time. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 21 2.55 -23 37.6 1.680 1.618 68 18.3 4:07 (310, 11) Apr. 17 21 26.55 -22 5.6 1.575 1.552 70 17.7 3:56 (307, 11) 152P/Helin-Lawrence Now it is 17.6 mag (Apr. 11, Toshihiko Ikemura, Hirohisa Sato). It will brighten up to 16 mag in 2022. In 2021, it stays observable at 18 mag until September. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 13 45.13 3 7.4 2.443 3.426 166 17.8 0:34 ( 0, 58) Apr. 17 13 40.69 3 28.7 2.428 3.411 166 17.8 0:02 ( 0, 58) C/2019 E3 ( ATLAS ) It stays 17-18 mag for a long time until 2026. In the Southern Hemisphere, it stays sobservable in good condition for a long time. It is not observable in the Northern Hemisphere. Now it is 19.7 mag (Mar. 13, A. C. Gilmore, P. M. Kilmartin), fainter than this ephemeris. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 8 53.96 -55 57.8 11.091 11.477 110 17.8 19:55 ( 2, -1) Apr. 17 8 51.54 -55 34.9 11.101 11.461 108 17.8 20:03 ( 8, -1) C/2020 K1 ( PanSTARRS ) Now it is 17.5 mag (Apr. 11, Toshihiko Ikemura, Hirohisa Sato). It is expected to brighten up to 12 mag in 2023. In the Northern Hemisphere, it is observable in good condition in 2021. But it is observable only until November in 2022. In the Southern Hemisphere, it locates extremely low in 2021. But it will be observable in good condition at the high light. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 49.86 43 35.8 7.259 7.310 88 17.9 4:07 (237, 71) Apr. 17 18 48.99 44 8.3 7.162 7.262 91 17.9 3:56 (231, 73) C/2021 C4 ( ATLAS ) Now it is 17.5 mag (Mar. 15, Giuseppe Pappa). It is observable at 18 mag in spring. It is observable in excellent condition in the Southern Hemisphere. It locates low in the Northern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 13 43.17 -37 44.3 3.664 4.555 149 17.9 0:32 ( 0, 17) Apr. 17 13 31.88 -36 2.4 3.638 4.564 154 17.9 23:48 ( 0, 19) 162P/Siding Spring Now it is 17.4 mag (Apr. 9, Toshihiko Ikemura, Hirohisa Sato). It will be fading after this, and will be fainter than 18 mag in April. In the Northern Hemisphere, it stays observable in good condition for a long time after this. In the Southern Hemisphere, it will never be unobservable after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 4 47.31 45 23.6 2.155 1.853 59 17.9 19:55 (123, 40) Apr. 17 5 11.88 45 42.9 2.249 1.902 57 18.0 20:03 (124, 39) C/2020 Y3 ( ATLAS ) Now it is 17.5 mag (Mar. 30, Thomas Lehmann). It will be fading after this. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 14 30.76 43 47.2 1.786 2.504 125 17.9 1:19 (180, 81) Apr. 17 14 20.51 47 0.2 1.876 2.553 121 18.1 0:41 (180, 78) C/2016 Q2 ( PanSTARRS ) Now it is 17.6 mag (Mar. 17, Toshihiko Ikemura, Hirohisa Sato). In the Northern Hemisphere, it stays observable at 18 mag for a long time from 2021 to 2022. It is not observable in the Southern Hemisphere. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 18 14.08 48 59.1 6.949 7.085 93 18.0 4:07 (211, 73) Apr. 17 18 9.44 50 12.1 6.909 7.084 95 17.9 3:56 (199, 74) 47P/Ashbrook-Jackson Now it is 18.6 mag (Apr. 4, Michael Jager). Although it is around the aphelion, it is much brighter than originally predicted. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 10 48.74 10 37.4 4.608 5.408 139 18.1 21:33 ( 0, 66) Apr. 17 10 46.38 10 41.1 4.687 5.411 131 18.2 21:03 ( 0, 66) 141P/Machholz 2 It brightened very rapidly in early December, and it brightened up to 10.0 mag in January (Jan. 7, Michael Jager). Now it is fading. However, it brightened in outburst in early March up to 12.9 mag (Mar. 3, Martin Masek). Now it is 16.8 mag (Mar. 31, Thomas Lehmann). Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 7 9.25 6 7.6 1.537 1.805 87 18.6 19:55 ( 51, 50) Apr. 17 7 24.95 6 14.0 1.670 1.876 85 19.2 20:03 ( 56, 47) P/1999 J6 = P/2004 V9 = P/2010 H3 ( SOHO ) Marsden group's comet. Three apparitions of this comet was confirmed in 1999, 2004 and 2010. It approached to Sun down to 0.044 a.u. on Feb. 28. After the perihelion passage, it may be observed on the ground from March to April. Date(TT) R.A. (2000) Decl. Delta r Elong. m1 Best Time(A, h) Apr. 10 21 5.14 -19 24.7 1.161 1.202 67 25.5 4:07 (306, 14) Apr. 17 20 57.88 -20 49.5 1.155 1.334 75 26.2 3:56 (311, 17)