P/2024 L4 (Rankin)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	14 Apr 2024	16.6	0.672 AU	0.387 AU	02h31m	+29°49'	24.8°	141.2°	38°
Nearest approach	27 Apr 2024	16.3	0.709 AU	0.341 AU	00h58m	+29°12'	24.2°	144.4°	305°
Today	21 Dec 2024	28.5	2.802 AU	3.252 AU	21h51m	-16°20'	54.8°	16.7°	73°

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 P/2024 L4 (Rankin) are:

            e (Eccentricity)                : 0.6983830
            q (Perihelion distance)         : 0.6720950
            i (Inclination)                 : 10.04650
            Ω (Longitude of ascending node) : 139.77750
            ω (Argument of perihelion)      : 53.70340
            L (Longitude of perihelion)     : 193.05753
            B (Latitude of perihelion)      : 8.08246
            T (Time of perihelion passage)  : 2460414.79010
            P (Orbital period in years)     : 3.33

            Epoch                           : 2024 Dec 20
            Reference                       : MPEC 2024-RQ6

            Classification(s):              : Ecliptic; Encke type; Active asteroid
            Tisserand (Jupiter)             : 3.257
        

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 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. (21.50 + 5 log[∆] + 10.00 log[r]). The additional green curve shows the effect of forward scattering, occurring when the comet is between the earth and the sun, for a gas-to-dust light ratio δ90 of 0.30. (See Marcus 2007)

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
2024-12-21 00:00 UT   21 51 06.7   -16 24 15     3.242    2.799   55.2   16.8    73   28.5 
2024-12-21 13:45 UT   21 51 50.0   -16 20 49     3.252    2.802   54.8   16.7    73   28.5 
2024-12-22 00:00 UT   21 52 22.2   -16 18 15     3.260    2.805   54.5   16.6    73   28.5 
2024-12-23 00:00 UT   21 53 37.7   -16 12 14     3.278    2.811   53.8   16.4    73   28.6 
2024-12-24 00:00 UT   21 54 53.3   -16 06 10     3.296    2.817   53.1   16.2    73   28.6 
2024-12-25 00:00 UT   21 56 09.0   -16 00 03     3.313    2.823   52.4   16.0    73   28.6 
2024-12-26 00:00 UT   21 57 24.8   -15 53 55     3.331    2.829   51.7   15.8    73   28.6 
2024-12-27 00:00 UT   21 58 40.6   -15 47 45     3.348    2.834   51.0   15.6    73   28.6 
2024-12-28 00:00 UT   21 59 56.5   -15 41 32     3.366    2.840   50.3   15.5    73   28.7 
2024-12-29 00:00 UT   22 01 12.5   -15 35 18     3.383    2.846   49.6   15.3    73   28.7 
2024-12-30 00:00 UT   22 02 28.5   -15 29 01     3.400    2.852   48.9   15.1    73   28.7 
2024-12-31 00:00 UT   22 03 44.6   -15 22 43     3.417    2.858   48.2   14.9    73   28.7 

    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.