C/2019 A9 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	27 Jul 2019	12.5	1.425 AU	2.134 AU	07h30m	-12°53'	34.9°	24.1°	203°
Nearest approach	5 Sep 2019	12.6	1.529 AU	1.914 AU	09h23m	-41°20'	52.7°	31.6°	209°
Today	30 Dec 2025	28.0	17.120 AU	17.993 AU	18h40m	+03°26'	26.6°	1.5°	1°

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 9.3 + 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/2019 A9 (PANSTARRS) are:

    e (Eccentricity)                : 0.9637930
    q (Perihelion distance)         : 1.4252580
    i (Inclination)                 : 84.40570
    Ω (Longitude of ascending node) : 278.47390
    ω (Argument of perihelion)      : 237.86970
    L (Longitude of perihelion)     : 287.29695
    B (Latitude of perihelion)      : -57.43777
    T (Time of perihelion passage)  : 2458692.20690
    P (Orbital period in years)     : 246.97

    Epoch                           : 2025 Nov 12
    Reference                       : MPC118842

    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
2025-12-29 00:00 UT   18 40 05.0   +03 25 09    17.984   17.112   26.8    1.5     5   27.9 
2025-12-30 00:00 UT   18 40 18.4   +03 25 40    17.989   17.117   26.6    1.5     2   27.9 
2025-12-30 15:48 UT   18 40 27.2   +03 26 01    17.993   17.120   26.6    1.5     1   28.0 
2025-12-31 00:00 UT   18 40 31.8   +03 26 12    17.995   17.121   26.6    1.5     0   28.0 
2026-01-01 00:00 UT   18 40 45.2   +03 26 46    18.000   17.126   26.5    1.5   358   28.0 
2026-01-02 00:00 UT   18 40 58.6   +03 27 22    18.005   17.131   26.5    1.5   356   28.0 
2026-01-03 00:00 UT   18 41 12.0   +03 27 59    18.010   17.136   26.5    1.5   354   28.0 
2026-01-04 00:00 UT   18 41 25.3   +03 28 37    18.015   17.141   26.5    1.5   352   28.0 
2026-01-05 00:00 UT   18 41 38.6   +03 29 17    18.019   17.146   26.6    1.5   349   28.0 
2026-01-06 00:00 UT   18 41 51.9   +03 29 59    18.023   17.151   26.7    1.5   347   28.0 
2026-01-07 00:00 UT   18 42 05.2   +03 30 42    18.027   17.156   26.9    1.5   345   28.0 
2026-01-08 00:00 UT   18 42 18.4   +03 31 26    18.030   17.161   27.1    1.5   343   28.0 
2026-01-09 00:00 UT   18 42 31.6   +03 32 12    18.033   17.166   27.3    1.5   341   28.0 

    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.