C/2019 Y4 (ATLAS) - DISINTEGRATED
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Disintegration	1 Apr 2020	8.1	1.458 AU	1.022 AU	07h58m	+69°28'	92.3°	43.2°	109°
Nearest approach	22 May 2020	-	0.370 AU	0.776 AU	03h42m	+38°38'	18.5°	119.8°	350°
Perihelion	30 May 2020	-	0.257 AU	0.871 AU	03h34m	+19°46'	13.0°	117.0°	259°
Today	7 Oct 2024	-	14.675 AU	14.779 AU	07h27m	+09°30'	82.1°	3.9°	277°

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)                : 0.9992550
            q (Perihelion distance)         : 0.2568090
            i (Inclination)                 : 45.02050
            Ω (Longitude of ascending node) : 120.75360
            ω (Argument of perihelion)      : 177.43120
            L (Longitude of perihelion)     : 118.93723
            B (Latitude of perihelion)      : 1.81676
            T (Time of perihelion passage)  : 2458999.73740
            P (Orbital period in years)     : 6400.01

            Epoch                           : 2024 Oct 05
            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 6.46 + 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
2024-10-07 00:00 UT   07 27 24.1   +09 30 46    14.779   14.674   82.0    3.9   277   24.0 
2024-10-07 01:27 UT   07 27 24.2   +09 30 43    14.779   14.675   82.1    3.9   277   24.0 
2024-10-08 00:00 UT   07 27 25.7   +09 29 59    14.769   14.681   83.0    3.9   277   24.0 
2024-10-09 00:00 UT   07 27 27.0   +09 29 12    14.758   14.687   83.9    3.9   277   24.0 
2024-10-10 00:00 UT   07 27 28.1   +09 28 26    14.748   14.693   84.9    3.9   278   24.0 
2024-10-11 00:00 UT   07 27 28.9   +09 27 41    14.737   14.699   85.8    3.9   278   24.0 
2024-10-12 00:00 UT   07 27 29.4   +09 26 56    14.727   14.705   86.8    3.9   278   24.0 
2024-10-13 00:00 UT   07 27 29.6   +09 26 12    14.716   14.712   87.8    3.9   278   24.0 
2024-10-14 00:00 UT   07 27 29.6   +09 25 28    14.706   14.718   88.7    3.9   278   24.0 
2024-10-15 00:00 UT   07 27 29.2   +09 24 45    14.695   14.724   89.7    3.9   279   24.0 
2024-10-16 00:00 UT   07 27 28.6   +09 24 02    14.684   14.730   90.7    3.9   279   24.0 
2024-10-17 00:00 UT   07 27 27.7   +09 23 20    14.674   14.737   91.6    3.9   279   24.0 

    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.