C/2025 Q1 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	12 Jun 2024	18.8	10.101 AU	9.710 AU	09h10m	-84°09'	109.9°	5.4°	125°
Perihelion	11 Jul 2024	18.8	10.100 AU	9.757 AU	10h15m	-83°14'	106.9°	5.5°	139°
Today	26 Feb 2026	19.3	10.593 AU	11.124 AU	21h38m	-62°54'	55.3°	4.4°	198°

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. (3.8 + 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/2025 Q1 (ATLAS) are:

    e (Eccentricity)                : 0.9921900
    q (Perihelion distance)         : 10.0995550
    i (Inclination)                 : 66.16250
    Ω (Longitude of ascending node) : 326.94380
    ω (Argument of perihelion)      : 280.23270
    L (Longitude of perihelion)     : 261.01252
    B (Latitude of perihelion)      : -64.17734
    T (Time of perihelion passage)  : 2460503.39540
    P (Orbital period in years)     : 46502.55

    Epoch                           : 2026 Feb 26
    Reference                       : MPC191591

    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
2026-02-25 00:00 UT   21 36 47.6   -62 58 36    11.133   10.590   54.6    4.4   197   19.3 
2026-02-26 00:00 UT   21 37 33.2   -62 56 16    11.128   10.591   55.0    4.4   197   19.3 
2026-02-26 18:09 UT   21 38 07.5   -62 54 32    11.124   10.593   55.3    4.4   198   19.3 
2026-02-27 00:00 UT   21 38 18.5   -62 53 59    11.123   10.593   55.4    4.4   198   19.3 
2026-02-28 00:00 UT   21 39 03.5   -62 51 46    11.118   10.595   55.9    4.4   199   19.3 
2026-03-01 00:00 UT   21 39 48.3   -62 49 36    11.113   10.596   56.3    4.5   200   19.3 
2026-03-02 00:00 UT   21 40 32.7   -62 47 29    11.108   10.598   56.8    4.5   201   19.3 
2026-03-03 00:00 UT   21 41 16.8   -62 45 25    11.102   10.599   57.3    4.5   202   19.3 
2026-03-04 00:00 UT   21 42 00.7   -62 43 25    11.097   10.601   57.7    4.5   202   19.3 
2026-03-05 00:00 UT   21 42 44.2   -62 41 29    11.091   10.603   58.2    4.6   203   19.3 
2026-03-06 00:00 UT   21 43 27.3   -62 39 36    11.085   10.604   58.7    4.6   204   19.3 
2026-03-07 00:00 UT   21 44 10.2   -62 37 46    11.080   10.606   59.2    4.6   205   19.3 
2026-03-08 00:00 UT   21 44 52.8   -62 35 60    11.073   10.608   59.7    4.6   205   19.3 

    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.