C/2026 M3 (MASTER)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	30 Jun 2026	20.0	12.103 AU	11.385 AU	18h25m	+23°39'	133.1°	3.5°	176°
Today	9 Aug 2026	20.0	12.087 AU	11.553 AU	18h11m	+23°59'	119.7°	4.2°	127°
Perihelion	27 Jan 2027	20.2	12.058 AU	12.633 AU	18h32m	+24°09'	52.4°	3.7°	322°

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)                : 0.9998650
    q (Perihelion distance)         : 12.0577150
    i (Inclination)                 : 93.87700
    Ω (Longitude of ascending node) : 282.34880
    ω (Argument of perihelion)      : 50.50260
    L (Longitude of perihelion)     : 277.65928
    B (Latitude of perihelion)      : 50.34379
    T (Time of perihelion passage)  : 2461432.81100

    Epoch                           : 2026 Aug 09
    Reference                       : MPEC 2026-P55

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-08-08 00:00 UT   18 12 03.5   +24 00 23    11.539   12.088  120.7    4.1   128   20.0 
2026-08-09 00:00 UT   18 11 45.7   +23 59 50    11.547   12.088  120.1    4.2   127   20.0 
2026-08-09 19:37 UT   18 11 31.4   +23 59 20    11.553   12.087  119.7    4.2   127   20.0 
2026-08-10 00:00 UT   18 11 28.2   +23 59 13    11.554   12.087  119.6    4.2   126   20.0 
2026-08-11 00:00 UT   18 11 11.1   +23 58 34    11.562   12.087  119.0    4.2   125   20.0 
2026-08-12 00:00 UT   18 10 54.2   +23 57 53    11.571   12.086  118.5    4.2   124   20.0 
2026-08-13 00:00 UT   18 10 37.6   +23 57 08    11.579   12.086  117.9    4.2   124   20.0 
2026-08-14 00:00 UT   18 10 21.4   +23 56 22    11.588   12.086  117.3    4.3   123   20.0 
2026-08-15 00:00 UT   18 10 05.4   +23 55 32    11.596   12.085  116.7    4.3   122   20.0 
2026-08-16 00:00 UT   18 09 49.7   +23 54 40    11.605   12.085  116.1    4.3   121   20.0 
2026-08-17 00:00 UT   18 09 34.4   +23 53 46    11.614   12.085  115.5    4.3   120   20.0 
2026-08-18 00:00 UT   18 09 19.4   +23 52 50    11.623   12.084  114.9    4.4   119   20.0 
2026-08-19 00:00 UT   18 09 04.7   +23 51 51    11.632   12.084  114.3    4.4   118   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.