C/2020 A2 (Iwamoto)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	6 Jan 2020	10.3	0.978 AU	1.632 AU	17h47m	+05°12'	33.6°	33.8°	327°
Nearest approach	20 Feb 2020	10.1	1.246 AU	0.913 AU	19h46m	+66°07'	81.7°	51.8°	324°
Today	27 Jul 2026	28.5	18.718 AU	19.350 AU	05h40m	-10°22'	50.3°	2.4°	234°

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 9.4 + 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 A2 (Iwamoto) are:

    e (Eccentricity)                : 0.9988840
    q (Perihelion distance)         : 0.9781780
    i (Inclination)                 : 120.49930
    Ω (Longitude of ascending node) : 286.18330
    ω (Argument of perihelion)      : 68.04090
    L (Longitude of perihelion)     : 234.64804
    B (Latitude of perihelion)      : 53.04659
    T (Time of perihelion passage)  : 2458854.52080
    P (Orbital period in years)     : 25949.59

    Epoch                           : 2026 May 29
    Reference                       : MPC194165

    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
2026-07-26 00:00 UT   05 40 19.9   -10 20 16    19.355   18.710   49.4    2.4   233   28.5 
2026-07-27 00:00 UT   05 40 28.9   -10 21 27    19.351   18.716   50.0    2.4   234   28.5 
2026-07-27 12:37 UT   05 40 33.5   -10 22 04    19.350   18.718   50.3    2.4   234   28.5 
2026-07-28 00:00 UT   05 40 37.7   -10 22 39    19.348   18.721   50.6    2.4   235   28.5 
2026-07-29 00:00 UT   05 40 46.4   -10 23 52    19.344   18.726   51.3    2.4   235   28.5 
2026-07-30 00:00 UT   05 40 55.0   -10 25 06    19.340   18.732   52.0    2.4   236   28.5 
2026-07-31 00:00 UT   05 41 03.5   -10 26 22    19.336   18.737   52.6    2.5   237   28.5 
2026-08-01 00:00 UT   05 41 11.8   -10 27 39    19.331   18.743   53.3    2.5   238   28.5 
2026-08-02 00:00 UT   05 41 20.0   -10 28 58    19.327   18.748   54.0    2.5   239   28.5 
2026-08-03 00:00 UT   05 41 28.1   -10 30 17    19.322   18.754   54.6    2.5   239   28.5 
2026-08-04 00:00 UT   05 41 36.0   -10 31 39    19.317   18.759   55.3    2.5   240   28.5 
2026-08-05 00:00 UT   05 41 43.8   -10 33 01    19.312   18.764   56.0    2.6   241   28.5 
2026-08-06 00:00 UT   05 41 51.4   -10 34 25    19.307   18.770   56.7    2.6   242   28.5 

    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.