A/2025 A1
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	19 Oct 2025	20.0	6.514 AU	6.594 AU	08h41m	+28°17'	81.1°	8.7°	287°
Nearest approach	5 Mar 2027	18.6	5.344 AU	4.517 AU	12h13m	+39°26'	143.1°	6.4°	210°
Perihelion	13 Mar 2027	18.6	5.343 AU	4.524 AU	12h11m	+39°55'	142.1°	6.6°	197°

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)                : 1.0022410
    q (Perihelion distance)         : 5.3433280
    i (Inclination)                 : 33.42440
    Ω (Longitude of ascending node) : 101.33120
    ω (Argument of perihelion)      : 68.09400
    L (Longitude of perihelion)     : 165.60630
    B (Latitude of perihelion)      : 30.73475
    T (Time of perihelion passage)  : 2461477.53720

    Epoch                           : 2025 Oct 18
    Reference                       : MPC188412

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-10-18 00:00 UT   08 40 21.9   +28 14 09     6.628    6.521   79.5    8.6   287   20.0 
2025-10-19 00:00 UT   08 40 50.8   +28 16 19     6.608    6.517   80.4    8.7   287   20.0 
2025-10-19 17:05 UT   08 41 11.0   +28 17 54     6.594    6.514   81.1    8.7   287   20.0 
2025-10-20 00:00 UT   08 41 19.2   +28 18 33     6.588    6.512   81.3    8.7   287   20.0 
2025-10-21 00:00 UT   08 41 47.1   +28 20 49     6.568    6.508   82.2    8.7   287   19.9 
2025-10-22 00:00 UT   08 42 14.5   +28 23 09     6.549    6.504   83.1    8.7   286   19.9 
2025-10-23 00:00 UT   08 42 41.4   +28 25 32     6.529    6.500   84.0    8.8   286   19.9 
2025-10-24 00:00 UT   08 43 07.8   +28 27 58     6.509    6.496   84.9    8.8   286   19.9 
2025-10-25 00:00 UT   08 43 33.8   +28 30 27     6.489    6.492   85.8    8.8   286   19.9 
2025-10-26 00:00 UT   08 43 59.2   +28 33 00     6.469    6.488   86.7    8.8   286   19.9 
2025-10-27 00:00 UT   08 44 24.0   +28 35 36     6.449    6.484   87.6    8.8   286   19.9 
2025-10-28 00:00 UT   08 44 48.4   +28 38 15     6.430    6.480   88.5    8.8   286   19.9 
2025-10-29 00:00 UT   08 45 12.2   +28 40 58     6.410    6.476   89.4    8.8   286   19.9 

    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.