C/2019 Y4 (ATLAS) - DISINTEGRATED
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Disintegration	1 Apr 2020	8.1	1.455 AU	1.019 AU	07h57m	+69°35'	92.2°	43.3°	109°
Nearest approach	21 May 2020	-	0.372 AU	0.776 AU	03h41m	+38°43'	18.6°	119.6°	350°
Perihelion	30 May 2020	-	0.257 AU	0.871 AU	03h33m	+19°44'	13.1°	116.9°	259°
Today	21 Dec 2024	-	15.142 AU	14.233 AU	07h17m	+09°09'	156.7°	1.5°	310°

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.)

The orbital elements of C/2019 Y4 (ATLAS) are:

            e (Eccentricity)                : 0.9992460
            q (Perihelion distance)         : 0.2570350
            i (Inclination)                 : 44.98800
            Ω (Longitude of ascending node) : 120.76800
            ω (Argument of perihelion)      : 177.42580
            L (Longitude of perihelion)     : 118.94677
            B (Latitude of perihelion)      : 1.81955
            T (Time of perihelion passage)  : 2458999.58410
            P (Orbital period in years)     : 6294.07

            Epoch                           : 2024 Dec 20
            Reference                       : MPEC 2024-A43

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

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (11.80 + 5 log[∆] + 15.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 6.47 + 5 log[∆] + 10.00 log[r]). The additional green curve shows the effect of forward scattering, occurring when the comet is between the earth and the sun, for a gas-to-dust light ratio δ90 of 0.50. (See Marcus 2007)

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2024-12-21 00:00 UT   07 17 22.3   +09 09 04    14.233   15.138  156.0    1.5   309   24.0 
2024-12-21 18:53 UT   07 17 10.0   +09 09 21    14.233   15.142  156.7    1.5   310   24.0 
2024-12-22 00:00 UT   07 17 06.7   +09 09 26    14.233   15.144  156.9    1.5   310   24.0 
2024-12-23 00:00 UT   07 16 50.9   +09 09 49    14.234   15.150  157.8    1.4   312   24.0 
2024-12-24 00:00 UT   07 16 35.2   +09 10 13    14.235   15.156  158.7    1.4   314   24.0 
2024-12-25 00:00 UT   07 16 19.3   +09 10 38    14.236   15.162  159.5    1.3   316   24.0 
2024-12-26 00:00 UT   07 16 03.3   +09 11 04    14.238   15.168  160.3    1.3   318   24.1 
2024-12-27 00:00 UT   07 15 47.3   +09 11 31    14.240   15.174  161.1    1.2   320   24.1 
2024-12-28 00:00 UT   07 15 31.3   +09 11 59    14.242   15.180  161.9    1.2   322   24.1 
2024-12-29 00:00 UT   07 15 15.1   +09 12 28    14.245   15.187  162.6    1.1   325   24.1 
2024-12-30 00:00 UT   07 14 59.0   +09 12 58    14.248   15.193  163.3    1.1   328   24.1 
2024-12-31 00:00 UT   07 14 42.8   +09 13 29    14.251   15.199  164.0    1.0   331   24.1 

    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.