C/2025 K1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	8 Aug 2025	12.1	1.448 AU	0.593 AU	18h29m	+19°31'	126.5°	34.3°	129°
Perihelion	8 Oct 2025	7.2	0.334 AU	1.292 AU	12h35m	-12°27'	8.1°	25.0°	217°
Nearest approach	24 Nov 2025	10.4	1.193 AU	0.401 AU	09h34m	+63°55'	111.3°	50.4°	274°

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.)

The orbital elements of C/2025 K1 (ATLAS) are:

            e (Eccentricity)                : 1.0002910
            q (Perihelion distance)         : 0.3342150
            i (Inclination)                 : 147.86520
            Ω (Longitude of ascending node) : 97.55600
            ω (Argument of perihelion)      : 271.02160
            L (Longitude of perihelion)     : 186.34962
            B (Latitude of perihelion)      : -32.12908
            T (Time of perihelion passage)  : 2460956.93900

            Epoch                           : 2025 Aug 07
            Reference                       : MPEC 2025-PB3

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

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (12.20 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 11.55 + 5 log[∆] + 10.41 log[r]).

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-08-08 00:00 UT   18 33 01.2   +19 44 53     0.595    1.452  127.0   33.9   130   12.1 
2025-08-08 01:00 UT   18 32 33.0   +19 42 53     0.595    1.452  126.9   33.9   130   12.1 
2025-08-08 02:00 UT   18 32 04.8   +19 40 52     0.595    1.451  126.9   34.0   130   12.1 
2025-08-08 03:00 UT   18 31 36.6   +19 38 50     0.594    1.450  126.8   34.1   130   12.1 
2025-08-08 04:00 UT   18 31 08.4   +19 36 48     0.594    1.449  126.7   34.1   129   12.1 
2025-08-08 05:00 UT   18 30 40.1   +19 34 46     0.594    1.449  126.6   34.2   129   12.1 
2025-08-08 06:00 UT   18 30 11.9   +19 32 43     0.594    1.448  126.5   34.2   129   12.1 
2025-08-08 06:29 UT   18 29 58.2   +19 31 44     0.593    1.448  126.5   34.3   129   12.1 
2025-08-08 07:00 UT   18 29 43.6   +19 30 40     0.593    1.447  126.4   34.3   129   12.1 
2025-08-08 08:00 UT   18 29 15.3   +19 28 37     0.593    1.446  126.3   34.4   129   12.1 
2025-08-08 09:00 UT   18 28 47.0   +19 26 33     0.593    1.446  126.3   34.4   129   12.1 
2025-08-08 10:00 UT   18 28 18.8   +19 24 28     0.593    1.445  126.2   34.5   128   12.1 
2025-08-08 11:00 UT   18 27 50.5   +19 22 23     0.592    1.444  126.1   34.6   128   12.1 
2025-08-08 12:00 UT   18 27 22.1   +19 20 18     0.592    1.443  126.0   34.6   128   12.1 
2025-08-08 13:00 UT   18 26 53.8   +19 18 12     0.592    1.443  125.9   34.7   128   12.1 
2025-08-08 14:00 UT   18 26 25.5   +19 16 06     0.591    1.442  125.8   34.8   128   12.1 
2025-08-08 15:00 UT   18 25 57.2   +19 13 59     0.591    1.441  125.7   34.8   128   12.1 
2025-08-08 16:00 UT   18 25 28.8   +19 11 52     0.591    1.441  125.6   34.9   128   12.1 
2025-08-08 17:00 UT   18 25 00.5   +19 09 44     0.591    1.440  125.5   35.0   127   12.1 
2025-08-08 18:00 UT   18 24 32.1   +19 07 36     0.590    1.439  125.5   35.0   127   12.1 
2025-08-08 19:00 UT   18 24 03.8   +19 05 28     0.590    1.438  125.4   35.1   127   12.0 
2025-08-08 20:00 UT   18 23 35.4   +19 03 19     0.590    1.438  125.3   35.1   127   12.0 
2025-08-08 21:00 UT   18 23 07.1   +19 01 09     0.590    1.437  125.2   35.2   127   12.0 
2025-08-08 22:00 UT   18 22 38.7   +18 58 60     0.589    1.436  125.1   35.3   127   12.0 
2025-08-08 23:00 UT   18 22 10.3   +18 56 50     0.589    1.435  125.0   35.3   127   12.0 
2025-08-09 00:00 UT   18 21 41.9   +18 54 39     0.589    1.435  124.9   35.4   126   12.0 

    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.