C/2020 Q1 (Borisov)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	15 Aug 2020	14.1	1.320 AU	1.540 AU	05h37m	+28°31'	58.0°	40.6°	271°
Nearest approach	25 Sep 2020	12.9	1.452 AU	0.727 AU	23h48m	+67°50'	113.2°	39.4°	174°
Today	17 Mar 2026	30.0	15.961 AU	15.715 AU	16h53m	-09°38'	102.5°	3.5°	274°

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)                : 0.9789600
    q (Perihelion distance)         : 1.3200510
    i (Inclination)                 : 142.90150
    Ω (Longitude of ascending node) : 52.41500
    ω (Argument of perihelion)      : 10.06360
    L (Longitude of perihelion)     : 44.35823
    B (Latitude of perihelion)      : 6.05031
    T (Time of perihelion passage)  : 2459077.11890
    P (Orbital period in years)     : 496.96

    Epoch                           : 2026 Mar 16
    Reference                       : MPEC 2026-E44

    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
2026-03-16 00:00 UT   16 53 43.1   -09 39 37    15.727   15.955  101.5    3.5   274   30.0 
2026-03-17 00:00 UT   16 53 38.8   -09 38 53    15.715   15.961  102.5    3.5   274   30.0 
2026-03-17 00:15 UT   16 53 38.8   -09 38 52    15.715   15.961  102.5    3.5   274   30.0 
2026-03-18 00:00 UT   16 53 34.3   -09 38 08    15.704   15.966  103.5    3.5   274   30.0 
2026-03-19 00:00 UT   16 53 29.5   -09 37 24    15.693   15.972  104.5    3.5   273   30.0 
2026-03-20 00:00 UT   16 53 24.4   -09 36 39    15.682   15.977  105.5    3.4   273   30.0 
2026-03-21 00:00 UT   16 53 19.1   -09 35 54    15.671   15.982  106.4    3.4   273   30.0 
2026-03-22 00:00 UT   16 53 13.5   -09 35 08    15.660   15.988  107.4    3.4   273   30.0 
2026-03-23 00:00 UT   16 53 07.6   -09 34 23    15.650   15.993  108.4    3.4   272   30.0 
2026-03-24 00:00 UT   16 53 01.5   -09 33 37    15.639   15.999  109.4    3.4   272   30.0 
2026-03-25 00:00 UT   16 52 55.1   -09 32 51    15.628   16.004  110.4    3.3   272   30.0 
2026-03-26 00:00 UT   16 52 48.5   -09 32 05    15.618   16.009  111.4    3.3   272   30.0 
2026-03-27 00:00 UT   16 52 41.6   -09 31 18    15.608   16.015  112.4    3.3   271   30.0 

    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.