C/2019 Y1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	17 Mar 2020	8.1	0.826 AU	1.471 AU	00h09m	+30°47'	32.4°	40.2°	10°
Nearest approach	3 May 2020	9.8	1.194 AU	1.093 AU	06h10m	+81°48'	69.1°	52.1°	54°
Today	7 Mar 2026	33.0	17.319 AU	16.872 AU	13h58m	-47°52'	115.3°	3.0°	312°

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 8.5 + 5 log[∆] + 14.9 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/2019 Y1 (ATLAS) are:

    e (Eccentricity)                : 0.9906510
    q (Perihelion distance)         : 0.8262540
    i (Inclination)                 : 73.23810
    Ω (Longitude of ascending node) : 31.44920
    ω (Argument of perihelion)      : 57.92400
    L (Longitude of perihelion)     : 56.15964
    B (Latitude of perihelion)      : 54.22726
    T (Time of perihelion passage)  : 2458925.85870
    P (Orbital period in years)     : 830.85

    Epoch                           : 2025 Nov 12
    Reference                       : MPC119999

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years); Liller

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-03-06 00:00 UT   13 58 45.9   -47 50 41    16.882   17.312  114.1    3.0   311   33.0 
2026-03-07 00:00 UT   13 58 32.2   -47 51 45    16.875   17.317  114.9    3.0   312   33.0 
2026-03-07 09:27 UT   13 58 26.7   -47 52 09    16.872   17.319  115.3    3.0   312   33.0 
2026-03-08 00:00 UT   13 58 18.1   -47 52 46    16.868   17.322  115.7    3.0   313   33.0 
2026-03-09 00:00 UT   13 58 03.8   -47 53 45    16.861   17.328  116.6    2.9   314   33.0 
2026-03-10 00:00 UT   13 57 49.3   -47 54 42    16.854   17.333  117.4    2.9   314   33.0 
2026-03-11 00:00 UT   13 57 34.5   -47 55 36    16.847   17.339  118.2    2.9   315   33.0 
2026-03-12 00:00 UT   13 57 19.4   -47 56 28    16.841   17.344  119.0    2.9   316   33.0 
2026-03-13 00:00 UT   13 57 04.1   -47 57 17    16.834   17.349  119.8    2.9   317   33.0 
2026-03-14 00:00 UT   13 56 48.6   -47 58 04    16.828   17.355  120.5    2.8   318   33.0 
2026-03-15 00:00 UT   13 56 32.9   -47 58 49    16.822   17.360  121.3    2.8   318   33.0 
2026-03-16 00:00 UT   13 56 16.9   -47 59 31    16.816   17.366  122.1    2.8   319   33.0 
2026-03-17 00:00 UT   13 56 00.6   -48 00 11    16.810   17.371  122.9    2.8   320   33.1 

    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.