C/2024 B1 (Lemmon)
ephemeris date magn radius delta ra dec elong phase PA
Perihelion7 Oct 202414.51.634 AU1.996 AU 12h20m+48°15'54.6°29.9°350°
Nearest approach15 Oct 202414.51.637 AU1.988 AU 13h00m+46°24'55.1°30.0°354°
Today28 Oct 202623.07.790 AU8.474 AU 17h03m-32°56'44.0°5.1°106°
C/2024 B1 (Lemmon)- 2026-10-28
astro.vanbuitenen.nl


 
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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 11.3 + 5 log[∆] + 7.8 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 B1 (Lemmon) are:

    e (Eccentricity)                : 1.0013170
    q (Perihelion distance)         : 1.6339630
    i (Inclination)                 : 70.88150
    Ω (Longitude of ascending node) : 79.18640
    ω (Argument of perihelion)      : 66.23480
    L (Longitude of perihelion)     : 115.82891
    B (Latitude of perihelion)      : 59.85130
    T (Time of perihelion passage)  : 2460591.32630

    Epoch                           : 2026 Oct 23
    Reference                       : MPC194188

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-10-27 00:00 UT   17 02 32.8   -32 54 27     8.441    7.776   45.5    5.2   106   22.9 
2026-10-28 00:00 UT   17 03 00.5   -32 55 47     8.460    7.784   44.6    5.1   106   23.0 
2026-10-28 17:01 UT   17 03 20.3   -32 56 44     8.474    7.790   44.0    5.1   106   23.0 
2026-10-29 00:00 UT   17 03 28.5   -32 57 08     8.479    7.792   43.7    5.1   106   23.0 
2026-10-30 00:00 UT   17 03 56.8   -32 58 29     8.498    7.800   42.9    5.0   107   23.0 
2026-10-31 00:00 UT   17 04 25.3   -32 59 51     8.517    7.808   42.0    4.9   107   23.0 
2026-11-01 00:00 UT   17 04 54.1   -33 01 14     8.535    7.815   41.1    4.8   107   23.0 
2026-11-02 00:00 UT   17 05 23.2   -33 02 37     8.553    7.823   40.3    4.7   108   23.0 
2026-11-03 00:00 UT   17 05 52.5   -33 04 01     8.571    7.831   39.4    4.6   108   23.0 
2026-11-04 00:00 UT   17 06 22.0   -33 05 26     8.589    7.839   38.6    4.5   108   23.0 
2026-11-05 00:00 UT   17 06 51.8   -33 06 51     8.607    7.846   37.7    4.4   109   23.0 
2026-11-06 00:00 UT   17 07 21.8   -33 08 17     8.624    7.854   36.9    4.3   109   23.0 
2026-11-07 00:00 UT   17 07 52.0   -33 09 44     8.641    7.862   36.0    4.3   110   23.0 



    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.