C/2020 Q1 (Borisov)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	15 Aug 2020	14.1	1.319 AU	1.541 AU	05h37m	+28°30'	57.9°	40.5°	271°
Nearest approach	25 Sep 2020	12.9	1.452 AU	0.727 AU	23h48m	+67°51'	113.2°	39.4°	174°
Today	15 Oct 2025	29.8	15.122 AU	15.783 AU	16h32m	-09°06'	47.1°	2.8°	87°

The interactive orbit chart above shows the comet's path through the solar system and its position at the given date. Green and blue lines are shown perpendicular to the ecliptic plane: Green if the path is above the ecliptic plane, blue if it is below. (Left-click and drag to rotate the view; Right-click and drag to move the view; Use scroll wheel to zoom in our out.)

Light curve

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations from COBS. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 12.0 + 5 log[∆] + 10.0 log[r]). An additional green curve is displayed when an increase in apparent brightness is expected due to forward scattering of sunlight, which occurs when a dust-rich comet is located between the Earth and the Sun. (See Marcus 2007)

Charts

The all-sky chart below shows the path of the comet over the same period as the light curve. The comet's current position is marked yellow.

The following chart shows the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Orbital elements

The orbital elements of C/2020 Q1 (Borisov) are:

    e (Eccentricity)                : 0.9788890
    q (Perihelion distance)         : 1.3191710
    i (Inclination)                 : 142.91230
    Ω (Longitude of ascending node) : 52.41940
    ω (Argument of perihelion)      : 10.03660
    L (Longitude of perihelion)     : 44.38327
    B (Latitude of perihelion)      : 6.03267
    T (Time of perihelion passage)  : 2459077.01720
    P (Orbital period in years)     : 493.96

    Epoch                           : 2025 Oct 14
    Reference                       : MPEC 2022-L66

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-10-15 00:00 UT   16 31 57.2   -09 05 56    15.775   15.120   47.5    2.8    87   29.8 
2025-10-15 10:15 UT   16 32 01.1   -09 06 26    15.783   15.122   47.1    2.8    87   29.8 
2025-10-16 00:00 UT   16 32 06.3   -09 07 06    15.793   15.125   46.6    2.7    87   29.8 
2025-10-17 00:00 UT   16 32 15.6   -09 08 15    15.810   15.131   45.7    2.7    86   29.8 
2025-10-18 00:00 UT   16 32 25.1   -09 09 24    15.827   15.136   44.8    2.7    86   29.8 
2025-10-19 00:00 UT   16 32 34.7   -09 10 32    15.844   15.142   43.9    2.6    85   29.8 
2025-10-20 00:00 UT   16 32 44.5   -09 11 40    15.861   15.148   43.0    2.6    85   29.8 
2025-10-21 00:00 UT   16 32 54.4   -09 12 48    15.877   15.153   42.1    2.5    84   29.8 
2025-10-22 00:00 UT   16 33 04.5   -09 13 55    15.893   15.159   41.2    2.5    84   29.8 
2025-10-23 00:00 UT   16 33 14.8   -09 15 01    15.909   15.164   40.3    2.4    83   29.8 
2025-10-24 00:00 UT   16 33 25.2   -09 16 08    15.925   15.170   39.4    2.4    83   29.8 
2025-10-25 00:00 UT   16 33 35.7   -09 17 14    15.941   15.175   38.5    2.3    82   29.8 

    Terminology:
            
    delta:  distance between comet and earth in AU
    radius: distance between comet and sun in AU
    magn:   magnitude (brightness) estimate    
    ra:     right ascension in hours (24h = 360deg)
    dec:    declination in degrees
    elong:  elongation in degrees (angle sun-earth-comet)    
    phase:  phase angle in degrees (angle sun-comet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km      
    

Orbital elements usually provided by the MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database) or the MPC (Minor Planet Center)
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.