A/2025 A1
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	14 Sep 2026	19.4	5.503 AU	6.345 AU	10h37m	+31°15'	30.6°	5.3°	334°
Nearest approach	5 Mar 2027	18.6	5.336 AU	4.510 AU	12h13m	+39°26'	143.1°	6.4°	210°
Perihelion	15 Mar 2027	18.6	5.335 AU	4.520 AU	12h10m	+40°03'	141.6°	6.6°	193°

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 displayed light curve is calculated under the assumption that the object remains inactive. (H=11.20; G=.15).

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 A/2025 A1 are:

    e (Eccentricity)                : 0.9990090
    q (Perihelion distance)         : 5.3354250
    i (Inclination)                 : 33.39700
    Ω (Longitude of ascending node) : 101.29640
    ω (Argument of perihelion)      : 68.38730
    L (Longitude of perihelion)     : 165.91007
    B (Latitude of perihelion)      : 30.77970
    T (Time of perihelion passage)  : 2461479.86580
    P (Orbital period in years)     : 395041.80

    Epoch                           : 2026 Sep 14
    Reference                       : MPEC 2026-M30

    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
2026-09-13 00:00 UT   10 35 23.3   +31 20 31     6.360    5.506   29.5    5.2   335   19.4 
2026-09-14 00:00 UT   10 36 28.4   +31 18 06     6.352    5.505   30.1    5.3   335   19.4 
2026-09-14 22:29 UT   10 37 29.2   +31 15 51     6.345    5.503   30.6    5.3   334   19.4 
2026-09-15 00:00 UT   10 37 33.3   +31 15 42     6.345    5.503   30.6    5.3   334   19.4 
2026-09-16 00:00 UT   10 38 38.2   +31 13 21     6.337    5.501   31.2    5.4   333   19.4 
2026-09-17 00:00 UT   10 39 43.0   +31 11 01     6.329    5.499   31.7    5.5   332   19.4 
2026-09-18 00:00 UT   10 40 47.8   +31 08 44     6.320    5.497   32.3    5.6   331   19.4 
2026-09-19 00:00 UT   10 41 52.5   +31 06 29     6.312    5.496   32.9    5.7   330   19.4 
2026-09-20 00:00 UT   10 42 57.1   +31 04 16     6.304    5.494   33.5    5.8   330   19.4 
2026-09-21 00:00 UT   10 44 01.6   +31 02 05     6.295    5.492   34.1    5.9   329   19.4 
2026-09-22 00:00 UT   10 45 06.0   +30 59 56     6.286    5.490   34.7    6.0   328   19.4 
2026-09-23 00:00 UT   10 46 10.3   +30 57 49     6.277    5.489   35.3    6.1   327   19.4 
2026-09-24 00:00 UT   10 47 14.6   +30 55 45     6.268    5.487   35.9    6.2   327   19.4 

    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.