Bright comets in the coming 3 months

The below table lists all comets that are expected to become brighter than magnitude 15 in the coming 3 months.
For detailed information about a comet, click on its designation.

Comet(s) Today Perihelion Nearest approach
designation magn delta radius date magn radius date magn delta
C/2021 A1 (Leonard)5.00.28 AU0.82 AU3 Jan 20226.40.62 AU12 Dec 20213.70.23 AU
C/2019 L3 (ATLAS)9.92.72 AU3.57 AU9 Jan 20229.83.55 AU6 Jan 20229.82.58 AU
67P/Churyumov-Gerasimenko10.10.43 AU1.30 AU2 Nov 20219.51.21 AU12 Nov 20219.50.42 AU
19P/Borrelly10.21.17 AU1.46 AU1 Feb 20229.01.31 AU11 Dec 202110.11.17 AU
29P/Schwassmann-Wachmann11.04.97 AU5.94 AU2 Apr 201911.55.77 AU9 Sep 201810.84.78 AU
4P/Faye12.00.94 AU1.86 AU8 Sep 202111.51.62 AU5 Dec 202111.90.94 AU
C/2017 K2 (PANSTARRS)12.15.32 AU4.60 AU19 Dec 20227.11.80 AU14 Jul 20227.81.81 AU
9P/Tempel12.22.42 AU1.75 AU4 Mar 202210.11.54 AU28 Jul 202212.31.15 AU
57P/du Toit-Neujmin-Delporte12.22.26 AU1.79 AU17 Oct 202111.51.72 AU7 Jun 202111.71.13 AU
C/2019 T4 (ATLAS)12.94.74 AU4.50 AU9 Jun 202212.14.24 AU4 Apr 202211.83.33 AU
8P/Tuttle13.22.45 AU1.79 AU27 Aug 20218.41.03 AU12 Sep 20218.61.81 AU
104P/Kowal13.90.73 AU1.16 AU11 Jan 202213.01.07 AU28 Jan 202213.10.64 AU
132P/Helin-Roman-Alu14.41.03 AU1.71 AU13 Nov 202113.91.69 AU9 Oct 202113.70.74 AU
108P/Ciffreo14.40.98 AU1.88 AU10 Sep 202113.61.66 AU9 Dec 202114.40.98 AU
C/2021 O1 (Nishimura)14.82.98 AU2.12 AU13 Aug 20219.30.79 AU6 Aug 20219.41.70 AU
C/2020 U5 (PANSTARRS)15.23.45 AU3.95 AU27 Apr 202215.03.76 AU28 Dec 202115.03.39 AU
C/2020 Y2 (ATLAS)15.24.09 AU3.63 AU17 Jun 202214.23.13 AU19 Mar 202214.02.92 AU
117P/Helin-Roman-Alu15.34.16 AU3.21 AU7 Jul 202213.33.04 AU2 Jul 202213.32.03 AU
C/2020 V2 (ZTF)15.55.72 AU5.68 AU8 May 202310.72.23 AU17 Sep 202310.21.86 AU
C/2019 U5 (PANSTARRS)15.76.00 AU5.49 AU30 Mar 202312.03.62 AU24 Mar 202312.02.63 AU
116P/Wild15.72.14 AU2.65 AU16 Jul 202214.12.20 AU23 Feb 202213.81.44 AU
C/2021 E3 (ZTF)15.73.64 AU2.88 AU11 Jun 202211.81.78 AU31 May 202211.71.21 AU
6P/d'Arrest15.81.52 AU1.64 AU17 Sep 202112.21.35 AU2 Aug 202112.80.75 AU
107P/Wilson-Harrington16.33.69 AU2.80 AU24 Aug 20227.50.97 AU20 Jul 20227.30.40 AU
C/2021 O3 (PANSTARRS)17.02.63 AU2.61 AU21 Apr 20228.90.29 AU8 May 20229.50.60 AU
45P/Honda-Mrkos-Pajdusakova17.83.07 AU2.17 AU25 Apr 20224.50.56 AU10 May 20225.61.50 AU


For each of the listed comets, the current position is plotted in the below all-sky chart:





    Terminology:
            
    delta:      Distance between comet and earth in AU
    radius:     Distance between comet and sun in AU
    magn:       Magnitude (brightness) estimate    
    elong:      Elongation in degrees (angle sun-earth-comet)    
    AU:         Astronomical Unit (mean distance between earth and sun: 149597870.7 km
    Perihelion: On this date the comet (or other type of body) is closest to the sun
    

Orbital elements provided by MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database).
Calculations by a modified version of AAPlus, a C# implementation of the AA+ project by PJ Naughter from the algorithms presented in the book "Astronomical Algorithms" by Jean Meeus.
NGC2000 dso catalog and star labels from VizieR as provided by the Strasbourg astronomical Data Center.
Tycho2 catalog from the ESO archive.