C/2020 R7 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	15 Jul 2022	14.0	3.016 AU	2.175 AU	18h34m	-61°15'	138.9°	12.8°	22°
Perihelion	15 Sep 2022	14.5	2.950 AU	2.937 AU	16h41m	-33°29'	80.9°	19.7°	100°
Today	7 Dec 2025	22.2	10.135 AU	10.068 AU	13h52m	+60°38'	91.1°	5.6°	319°

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 7.8 + 5 log[∆] + 9.3 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 R7 (ATLAS) are:

    e (Eccentricity)                : 0.9994230
    q (Perihelion distance)         : 2.9502680
    i (Inclination)                 : 114.90340
    Ω (Longitude of ascending node) : 268.30840
    ω (Argument of perihelion)      : 347.73060
    L (Longitude of perihelion)     : 273.54077
    B (Latitude of perihelion)      : -11.11327
    T (Time of perihelion passage)  : 2459838.44020
    P (Orbital period in years)     : 365618.77

    Epoch                           : 2025 Dec 06
    Reference                       : MPEC 2024-PC5

    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
2025-12-06 00:00 UT   13 52 00.6   +60 32 04    10.071   10.126   90.4    5.6   320   22.2 
2025-12-07 00:00 UT   13 52 22.6   +60 36 34    10.069   10.133   90.9    5.6   319   22.2 
2025-12-07 08:37 UT   13 52 30.4   +60 38 13    10.068   10.135   91.1    5.6   319   22.2 
2025-12-08 00:00 UT   13 52 44.2   +60 41 10    10.067   10.139   91.4    5.6   318   22.2 
2025-12-09 00:00 UT   13 53 05.4   +60 45 50    10.065   10.146   91.9    5.6   317   22.2 
2025-12-10 00:00 UT   13 53 26.1   +60 50 34    10.063   10.152   92.4    5.6   316   22.2 
2025-12-11 00:00 UT   13 53 46.3   +60 55 23    10.061   10.158   92.9    5.6   316   22.2 
2025-12-12 00:00 UT   13 54 06.0   +61 00 16    10.060   10.165   93.3    5.5   315   22.2 
2025-12-13 00:00 UT   13 54 25.2   +61 05 14    10.058   10.171   93.8    5.5   314   22.2 
2025-12-14 00:00 UT   13 54 43.9   +61 10 16    10.056   10.178   94.3    5.5   313   22.2 
2025-12-15 00:00 UT   13 55 02.1   +61 15 22    10.055   10.184   94.8    5.5   312   22.2 
2025-12-16 00:00 UT   13 55 19.8   +61 20 32    10.053   10.191   95.2    5.5   311   22.2 
2025-12-17 00:00 UT   13 55 36.9   +61 25 47    10.051   10.197   95.7    5.5   310   22.2 

    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.