C/2019 A9 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	28 Jul 2019	12.5	1.424 AU	2.132 AU	07h31m	-12°56'	35.0°	24.1°	204°
Nearest approach	5 Sep 2019	12.6	1.527 AU	1.913 AU	09h23m	-41°19'	52.6°	31.6°	209°
Today	18 Jul 2026	28.1	18.088 AU	17.234 AU	18h36m	+07°29'	146.2°	1.8°	148°

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)                : 0.9638980
    q (Perihelion distance)         : 1.4236020
    i (Inclination)                 : 84.39450
    Ω (Longitude of ascending node) : 278.46760
    ω (Argument of perihelion)      : 237.85980
    L (Longitude of perihelion)     : 287.30465
    B (Latitude of perihelion)      : -57.42631
    T (Time of perihelion passage)  : 2458692.87260
    P (Orbital period in years)     : 247.62

    Epoch                           : 2026 May 29
    Reference                       : MPC194159

    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
2026-07-17 00:00 UT   18 37 13.6   +07 29 50    17.220   18.080  146.9    1.8   151   28.1 
2026-07-18 00:00 UT   18 37 00.6   +07 29 27    17.228   18.085  146.5    1.8   149   28.1 
2026-07-18 16:55 UT   18 36 51.5   +07 29 11    17.234   18.088  146.2    1.8   148   28.1 
2026-07-19 00:00 UT   18 36 47.7   +07 29 04    17.237   18.090  146.1    1.8   147   28.1 
2026-07-20 00:00 UT   18 36 34.9   +07 28 38    17.246   18.095  145.7    1.8   146   28.1 
2026-07-21 00:00 UT   18 36 22.2   +07 28 11    17.255   18.099  145.2    1.8   144   28.1 
2026-07-22 00:00 UT   18 36 09.6   +07 27 43    17.264   18.104  144.8    1.9   143   28.1 
2026-07-23 00:00 UT   18 35 57.1   +07 27 13    17.274   18.109  144.3    1.9   141   28.1 
2026-07-24 00:00 UT   18 35 44.7   +07 26 41    17.284   18.114  143.8    1.9   140   28.1 
2026-07-25 00:00 UT   18 35 32.4   +07 26 08    17.294   18.118  143.3    1.9   138   28.1 
2026-07-26 00:00 UT   18 35 20.1   +07 25 33    17.304   18.123  142.7    1.9   137   28.1 
2026-07-27 00:00 UT   18 35 08.0   +07 24 57    17.315   18.128  142.2    2.0   135   28.1 
2026-07-28 00:00 UT   18 34 56.1   +07 24 19    17.325   18.133  141.6    2.0   134   28.1 

    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.