C/2020 Q1 (Borisov)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	15 Aug 2020	14.1	1.319 AU	1.537 AU	05h38m	+28°32'	58.1°	40.6°	271°
Nearest approach	25 Sep 2020	12.9	1.451 AU	0.726 AU	23h49m	+67°53'	113.2°	39.4°	174°
Today	30 May 2026	30.1	16.362 AU	15.373 AU	16h38m	-08°48'	166.8°	0.8°	190°

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)                : 0.9789870
    q (Perihelion distance)         : 1.3194330
    i (Inclination)                 : 142.88820
    Ω (Longitude of ascending node) : 52.42340
    ω (Argument of perihelion)      : 10.06470
    L (Longitude of perihelion)     : 44.36714
    B (Latitude of perihelion)      : 6.05283
    T (Time of perihelion passage)  : 2459077.29880
    P (Orbital period in years)     : 497.56

    Epoch                           : 2026 May 29
    Reference                       : MPC194169

    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
2026-05-29 00:00 UT   16 38 54.8   -08 49 11    15.365   16.353  166.7    0.8   197   30.1 
2026-05-30 00:00 UT   16 38 38.2   -08 48 48    15.370   16.359  166.8    0.8   193   30.1 
2026-05-30 14:36 UT   16 38 28.2   -08 48 35    15.373   16.362  166.8    0.8   190   30.1 
2026-05-31 00:00 UT   16 38 21.7   -08 48 26    15.375   16.364  166.8    0.8   188   30.1 
2026-06-01 00:00 UT   16 38 05.1   -08 48 05    15.380   16.370  166.8    0.8   184   30.1 
2026-06-02 00:00 UT   16 37 48.5   -08 47 45    15.386   16.375  166.7    0.8   180   30.1 
2026-06-03 00:00 UT   16 37 32.0   -08 47 26    15.392   16.380  166.5    0.8   175   30.1 
2026-06-04 00:00 UT   16 37 15.5   -08 47 07    15.398   16.386  166.2    0.8   171   30.1 
2026-06-05 00:00 UT   16 36 59.0   -08 46 49    15.405   16.391  165.9    0.9   167   30.1 
2026-06-06 00:00 UT   16 36 42.5   -08 46 32    15.411   16.396  165.5    0.9   163   30.1 
2026-06-07 00:00 UT   16 36 26.1   -08 46 16    15.418   16.402  165.1    0.9   160   30.1 
2026-06-08 00:00 UT   16 36 09.7   -08 46 01    15.426   16.407  164.6    0.9   156   30.1 
2026-06-09 00:00 UT   16 35 53.3   -08 45 47    15.434   16.412  164.0    1.0   153   30.1 

    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.