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	1.245 AU	0.913 AU	19h47m	+66°06'	81.7°	51.8°	324°
Today	17 May 2026	28.4	18.330 AU	19.090 AU	05h27m	-10°02'	40.2°	2.0°	137°

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)                : 0.9988870
    q (Perihelion distance)         : 0.9780200
    i (Inclination)                 : 120.49830
    Ω (Longitude of ascending node) : 286.18220
    ω (Argument of perihelion)      : 68.03860
    L (Longitude of perihelion)     : 234.65099
    B (Latitude of perihelion)      : 53.04614
    T (Time of perihelion passage)  : 2458854.56770
    P (Orbital period in years)     : 26048.27

    Epoch                           : 2026 May 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
2026-05-16 00:00 UT   05 27 19.6   -10 03 46    19.072   18.322   41.0    2.1   135   28.4 
2026-05-17 00:00 UT   05 27 30.2   -10 03 04    19.083   18.327   40.5    2.1   136   28.4 
2026-05-17 13:05 UT   05 27 35.9   -10 02 42    19.090   18.330   40.2    2.0   137   28.4 
2026-05-18 00:00 UT   05 27 40.8   -10 02 23    19.095   18.333   40.0    2.0   137   28.4 
2026-05-19 00:00 UT   05 27 51.5   -10 01 45    19.106   18.338   39.5    2.0   139   28.4 
2026-05-20 00:00 UT   05 28 02.2   -10 01 07    19.117   18.344   39.1    2.0   140   28.4 
2026-05-21 00:00 UT   05 28 13.1   -10 00 31    19.128   18.349   38.6    2.0   141   28.4 
2026-05-22 00:00 UT   05 28 24.0   -09 59 57    19.139   18.355   38.2    2.0   142   28.4 
2026-05-23 00:00 UT   05 28 35.0   -09 59 25    19.149   18.360   37.8    1.9   144   28.4 
2026-05-24 00:00 UT   05 28 46.0   -09 58 53    19.159   18.366   37.4    1.9   145   28.4 
2026-05-25 00:00 UT   05 28 57.1   -09 58 24    19.169   18.371   37.0    1.9   147   28.4 
2026-05-26 00:00 UT   05 29 08.3   -09 57 56    19.179   18.377   36.6    1.9   148   28.4 
2026-05-27 00:00 UT   05 29 19.5   -09 57 29    19.189   18.382   36.3    1.9   149   28.4 

    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.