C/2019 Y5 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	16 Aug 2019	17.5	4.936 AU	4.923 AU	04h46m	-34°12'	84.8°	11.8°	249°
Nearest approach	9 Nov 2019	17.2	4.980 AU	4.338 AU	03h54m	-35°52'	125.6°	9.3°	343°
Today	30 Dec 2025	20.2	15.783 AU	15.356 AU	01h04m	+72°58'	114.0°	3.3°	89°

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 13.8 + 5 log[∆] + .4 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 Y5 (PANSTARRS) are:

    e (Eccentricity)                : 0.9927450
    q (Perihelion distance)         : 4.9362520
    i (Inclination)                 : 82.78220
    Ω (Longitude of ascending node) : 51.77810
    ω (Argument of perihelion)      : 303.67960
    L (Longitude of perihelion)     : 41.10107
    B (Latitude of perihelion)      : -55.64505
    T (Time of perihelion passage)  : 2458711.78960
    P (Orbital period in years)     : 17747.61

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2023-A50

    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   01 04 32.5   +73 03 16    15.341   15.776  114.6    3.2    91   20.2 
2025-12-30 00:00 UT   01 04 18.8   +73 00 15    15.352   15.781  114.2    3.3    90   20.2 
2025-12-30 10:14 UT   01 04 13.3   +72 58 58    15.356   15.783  114.0    3.3    89   20.2 
2025-12-31 00:00 UT   01 04 06.1   +72 57 15    15.363   15.786  113.8    3.3    89   20.2 
2026-01-01 00:00 UT   01 03 54.3   +72 54 14    15.374   15.791  113.4    3.3    87   20.2 
2026-01-02 00:00 UT   01 03 43.5   +72 51 14    15.386   15.796  113.0    3.3    86   20.2 
2026-01-03 00:00 UT   01 03 33.5   +72 48 15    15.397   15.801  112.6    3.3    85   20.2 
2026-01-04 00:00 UT   01 03 24.5   +72 45 16    15.409   15.806  112.1    3.3    84   20.2 
2026-01-05 00:00 UT   01 03 16.4   +72 42 17    15.421   15.811  111.7    3.3    83   20.2 
2026-01-06 00:00 UT   01 03 09.2   +72 39 20    15.433   15.816  111.2    3.3    82   20.2 
2026-01-07 00:00 UT   01 03 02.8   +72 36 23    15.445   15.821  110.8    3.3    81   20.2 
2026-01-08 00:00 UT   01 02 57.4   +72 33 27    15.457   15.826  110.3    3.3    80   20.2 
2026-01-09 00:00 UT   01 02 52.8   +72 30 32    15.470   15.831  109.9    3.3    79   20.2 

    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.