C/2026 M3 (MASTER)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	1 Jul 2026	20.0	12.104 AU	11.386 AU	18h25m	+23°39'	133.1°	3.5°	176°
Today	1 Sep 2026	20.1	12.078 AU	11.768 AU	18h06m	+23°35'	105.6°	4.6°	107°
Perihelion	17 Feb 2027	20.2	12.049 AU	12.479 AU	18h37m	+25°37'	62.1°	4.2°	301°

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. (3.9 + 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/2026 M3 (MASTER) are:

    e (Eccentricity)                : 1.0002400
    q (Perihelion distance)         : 12.0493530
    i (Inclination)                 : 93.88390
    Ω (Longitude of ascending node) : 282.35540
    ω (Argument of perihelion)      : 51.19900
    L (Longitude of perihelion)     : 277.54004
    B (Latitude of perihelion)      : 51.03563
    T (Time of perihelion passage)  : 2461453.61580

    Epoch                           : 2026 Aug 31
    Reference                       : MPEC 2026-Q97

    Classification(s):              : Nearly isotropic; New (a > 10000 AU)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-08-31 00:00 UT   18 06 34.7   +23 37 37    11.750   12.079  106.7    4.6   108   20.1 
2026-09-01 00:00 UT   18 06 24.5   +23 36 15    11.760   12.078  106.1    4.6   107   20.1 
2026-09-01 16:25 UT   18 06 17.7   +23 35 19    11.768   12.078  105.6    4.6   107   20.1 
2026-09-02 00:00 UT   18 06 14.6   +23 34 52    11.771   12.078  105.4    4.6   106   20.1 
2026-09-03 00:00 UT   18 06 05.2   +23 33 28    11.782   12.078  104.7    4.6   105   20.1 
2026-09-04 00:00 UT   18 05 56.0   +23 32 02    11.793   12.077  104.1    4.6   105   20.1 
2026-09-05 00:00 UT   18 05 47.3   +23 30 36    11.803   12.077  103.4    4.7   104   20.1 
2026-09-06 00:00 UT   18 05 38.9   +23 29 08    11.814   12.077  102.7    4.7   103   20.1 
2026-09-07 00:00 UT   18 05 30.9   +23 27 39    11.825   12.076  102.1    4.7   102   20.1 
2026-09-08 00:00 UT   18 05 23.2   +23 26 09    11.837   12.076  101.4    4.7   102   20.1 
2026-09-09 00:00 UT   18 05 15.9   +23 24 38    11.848   12.076  100.7    4.7   101   20.1 
2026-09-10 00:00 UT   18 05 09.0   +23 23 07    11.859   12.075  100.1    4.7   100   20.1 
2026-09-11 00:00 UT   18 05 02.5   +23 21 35    11.870   12.075   99.4    4.7    99   20.1 

    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.