C/2025 M1 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	20 Dec 2025	19.7	12.787 AU	13.717 AU	16h31m	-25°35'	18.4°	1.4°	267°
Nearest approach	23 Jun 2029	18.3	10.833 AU	10.113 AU	18h24m	-70°15'	133.1°	3.9°	355°
Perihelion	2 Aug 2029	18.3	10.831 AU	10.279 AU	17h53m	-70°45'	120.6°	4.6°	51°

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. The light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (2.9 + 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/2025 M1 (PANSTARRS) are:

    e (Eccentricity)                : 0.9979910
    q (Perihelion distance)         : 10.8307790
    i (Inclination)                 : 64.89450
    Ω (Longitude of ascending node) : 66.95830
    ω (Argument of perihelion)      : 230.40780
    L (Longitude of perihelion)     : 94.11686
    B (Latitude of perihelion)      : -44.25076
    T (Time of perihelion passage)  : 2462351.42340
    P (Orbital period in years)     : 395839.96

    Epoch                           : 2025 Dec 19
    Reference                       : MPC188414

    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
2025-12-19 00:00 UT   16 31 23.5   -25 32 40    13.727   12.790   17.3    1.3   267   19.7 
2025-12-20 00:00 UT   16 31 43.8   -25 34 52    13.719   12.788   18.2    1.4   267   19.7 
2025-12-20 04:10 UT   16 31 47.3   -25 35 15    13.717   12.787   18.4    1.4   267   19.7 
2025-12-21 00:00 UT   16 32 04.0   -25 37 05    13.711   12.785   19.1    1.4   268   19.7 
2025-12-22 00:00 UT   16 32 24.2   -25 39 18    13.702   12.782   20.0    1.5   268   19.7 
2025-12-23 00:00 UT   16 32 44.2   -25 41 31    13.693   12.780   21.0    1.6   269   19.6 
2025-12-24 00:00 UT   16 33 04.2   -25 43 43    13.685   12.777   21.9    1.6   269   19.6 
2025-12-25 00:00 UT   16 33 24.2   -25 45 56    13.675   12.774   22.8    1.7   269   19.6 
2025-12-26 00:00 UT   16 33 44.0   -25 48 09    13.666   12.772   23.8    1.8   270   19.6 
2025-12-27 00:00 UT   16 34 03.7   -25 50 22    13.656   12.769   24.7    1.8   270   19.6 
2025-12-28 00:00 UT   16 34 23.3   -25 52 35    13.646   12.766   25.6    1.9   270   19.6 
2025-12-29 00:00 UT   16 34 42.8   -25 54 48    13.636   12.764   26.6    2.0   271   19.6 
2025-12-30 00:00 UT   16 35 02.2   -25 57 01    13.625   12.761   27.5    2.0   271   19.6 

    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.