C/2020 Q1 (Borisov)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	15 Aug 2020	14.1	1.319 AU	1.540 AU	05h38m	+28°30'	57.9°	40.6°	271°
Nearest approach	25 Sep 2020	12.9	1.451 AU	0.727 AU	23h48m	+67°52'	113.2°	39.4°	174°
Today	28 Feb 2026	30.0	15.869 AU	15.908 AU	16h54m	-09°50'	85.9°	3.6°	278°

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)                : 0.9789010
    q (Perihelion distance)         : 1.3190280
    i (Inclination)                 : 142.90820
    Ω (Longitude of ascending node) : 52.42210
    ω (Argument of perihelion)      : 10.03800
    L (Longitude of perihelion)     : 44.38527
    B (Latitude of perihelion)      : 6.03408
    T (Time of perihelion passage)  : 2459077.08080
    P (Orbital period in years)     : 494.30

    Epoch                           : 2025 Nov 12
    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
2026-02-27 00:00 UT   16 54 18.6   -09 51 00    15.922   15.862   84.8    3.6   278   30.0 
2026-02-28 00:00 UT   16 54 18.8   -09 50 24    15.910   15.868   85.7    3.6   278   30.0 
2026-02-28 04:18 UT   16 54 18.8   -09 50 17    15.908   15.869   85.9    3.6   278   30.0 
2026-03-01 00:00 UT   16 54 18.7   -09 49 47    15.899   15.873   86.7    3.6   277   30.0 
2026-03-02 00:00 UT   16 54 18.4   -09 49 10    15.887   15.879   87.7    3.6   277   30.0 
2026-03-03 00:00 UT   16 54 17.9   -09 48 32    15.875   15.884   88.7    3.6   277   30.0 
2026-03-04 00:00 UT   16 54 17.0   -09 47 54    15.864   15.889   89.7    3.6   277   30.0 
2026-03-05 00:00 UT   16 54 15.9   -09 47 15    15.852   15.895   90.6    3.6   276   30.0 
2026-03-06 00:00 UT   16 54 14.6   -09 46 36    15.841   15.900   91.6    3.6   276   30.0 
2026-03-07 00:00 UT   16 54 13.0   -09 45 56    15.829   15.906   92.6    3.6   276   30.0 
2026-03-08 00:00 UT   16 54 11.1   -09 45 15    15.818   15.911   93.6    3.6   276   30.0 
2026-03-09 00:00 UT   16 54 08.9   -09 44 35    15.806   15.917   94.6    3.6   276   30.0 
2026-03-10 00:00 UT   16 54 06.5   -09 43 53    15.794   15.922   95.6    3.6   275   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.