C/2024 L5 (ATLAS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	10 Mar 2025	15.7	3.433 AU	2.748 AU	14h14m	-30°13'	126.5°	13.5°	302°
Nearest approach	10 Apr 2025	15.5	3.445 AU	2.474 AU	12h52m	-23°47'	163.3°	4.8°	20°
Today	19 Dec 2025	17.6	4.322 AU	4.054 AU	11h09m	+01°11'	99.2°	13.0°	294°

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. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 8.2 + 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/2024 L5 (ATLAS) are:

    e (Eccentricity)                : 1.0370240
    q (Perihelion distance)         : 3.4326860
    i (Inclination)                 : 166.57300
    Ω (Longitude of ascending node) : 139.17780
    ω (Argument of perihelion)      : 290.52550
    L (Longitude of perihelion)     : 208.12543
    B (Latitude of perihelion)      : -12.56018
    T (Time of perihelion passage)  : 2460744.92690

    Epoch                           : 2025 Dec 17
    Reference                       : MPEC 2025-XC7

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-18 00:00 UT   11 09 51.5   +01 05 60     4.069    4.316   97.9   13.1   293   17.6 
2025-12-19 00:00 UT   11 09 09.4   +01 11 23     4.055    4.321   99.1   13.0   294   17.6 
2025-12-19 01:42 UT   11 09 06.4   +01 11 46     4.054    4.322   99.2   13.0   294   17.6 
2025-12-20 00:00 UT   11 08 26.1   +01 16 54     4.041    4.327  100.3   12.9   294   17.6 
2025-12-21 00:00 UT   11 07 41.6   +01 22 34     4.027    4.332  101.5   12.9   294   17.6 
2025-12-22 00:00 UT   11 06 55.8   +01 28 22     4.013    4.338  102.8   12.8   294   17.6 
2025-12-23 00:00 UT   11 06 08.7   +01 34 18     3.999    4.343  104.0   12.7   294   17.6 
2025-12-24 00:00 UT   11 05 20.4   +01 40 23     3.985    4.349  105.2   12.6   294   17.6 
2025-12-25 00:00 UT   11 04 30.8   +01 46 37     3.971    4.354  106.5   12.5   294   17.6 
2025-12-26 00:00 UT   11 03 39.9   +01 52 60     3.958    4.360  107.7   12.4   294   17.6 
2025-12-27 00:00 UT   11 02 47.8   +01 59 31     3.944    4.365  109.0   12.3   294   17.5 
2025-12-28 00:00 UT   11 01 54.4   +02 06 10     3.931    4.371  110.3   12.2   294   17.5 
2025-12-29 00:00 UT   11 00 59.7   +02 12 59     3.918    4.376  111.5   12.1   294   17.5 

    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.