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
88P/Howell8.81.38 AU1.36 AU26 Sep 20209.41.35 AU10 May 202013.21.08 AU
C/2020 F3 (NEOWISE)9.82.24 AU1.73 AU3 Jul 20201.10.29 AU23 Jul 20203.30.69 AU
C/2020 M3 (ATLAS)10.40.63 AU1.39 AU25 Oct 20209.71.27 AU14 Nov 20209.60.36 AU
C/2017 T2 (PANSTARRS)11.53.02 AU2.39 AU4 May 20208.61.62 AU28 Dec 20199.81.52 AU
C/2019 Y4 (ATLAS)disintegrated2.56 AU2.30 AU31 May 2020-0.25 AU23 May 2020-0.78 AU
C/2020 Q1 (Borisov)12.70.78 AU1.41 AU15 Aug 202014.11.32 AU25 Sep 202012.90.73 AU
C/2019 N1 (ATLAS)13.32.87 AU1.96 AU1 Dec 202012.41.70 AU8 Feb 202112.31.91 AU
C/2019 U6 (Lemmon)13.31.95 AU1.77 AU18 Jun 20206.50.91 AU29 Jun 20206.50.83 AU
C/2020 K8 (Catalina-ATLAS)13.51.19 AU0.48 AU14 Sep 202013.30.47 AU14 Aug 202014.50.60 AU
C/2020 P1 (NEOWISE)13.60.90 AU0.89 AU20 Oct 20208.90.34 AU12 Oct 20209.00.66 AU
C/2020 F8 (SWAN)disintegrated2.26 AU2.22 AU27 May 2020-0.43 AU12 May 2020-0.56 AU
29P/Schwassmann-Wachmann14.05.18 AU5.82 AU16 Mar 201914.65.77 AU9 Sep 201813.84.77 AU
C/2020 P4-C (SOHO)14.31.43 AU1.28 AU6 Aug 20200.90.09 AU8 Aug 20202.60.91 AU
246P/NEAT14.43.75 AU2.99 AU22 Feb 202113.52.86 AU1 Jul 202112.81.94 AU
2P/Encke14.41.36 AU1.61 AU25 Jun 20206.70.34 AU30 Jul 20209.80.62 AU
C/2018 N2 (ASASSN)14.64.47 AU4.29 AU10 Nov 201911.73.12 AU19 Oct 201911.72.21 AU
162P/Siding Spring14.70.92 AU1.57 AU7 Dec 202013.81.29 AU27 Oct 202013.90.87 AU
102P/Shoemaker14.91.68 AU2.30 AU22 Jan 202115.02.07 AU10 Aug 202015.21.53 AU
C/2020 P4-B (SOHO)15.02.07 AU1.22 AU8 Aug 20200.80.10 AU6 Aug 20201.40.91 AU
10P/Tempel15.03.07 AU2.28 AU24 Mar 20219.11.41 AU3 Nov 202114.71.61 AU
C/2019 L3 (ATLAS)15.15.03 AU5.48 AU9 Jan 202211.73.55 AU6 Jan 202211.72.58 AU
156P/Russell-LINEAR15.20.57 AU1.50 AU17 Nov 202014.71.33 AU23 Oct 202014.60.48 AU
C/2017 K2 (PANSTARRS)15.68.32 AU8.24 AU19 Dec 20225.51.80 AU14 Jul 20226.51.81 AU
28P/Neujmin16.02.92 AU2.52 AU11 Mar 202112.71.58 AU6 Nov 202116.62.22 AU
7P/Pons-Winnecke16.43.71 AU2.83 AU27 May 20218.21.23 AU12 Jun 20218.20.44 AU
141P/Machholz16.81.31 AU1.53 AU15 Dec 20207.30.81 AU18 Jan 20219.00.52 AU
P/2020 P217.10.91 AU1.70 AU26 Dec 202014.01.31 AU22 Dec 202014.00.38 AU
P/2009 Q4 (Boattini)17.40.91 AU1.70 AU26 Dec 202013.21.31 AU22 Dec 202013.20.38 AU
11P/Tempel-Swift-LINEAR18.10.64 AU1.58 AU26 Nov 20209.11.39 AU3 Nov 20209.00.49 AU
141P-H/Machholz18.30.75 AU1.15 AU10 Nov 202014.00.76 AU4 Dec 202012.70.16 AU

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

    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.