C/2023 F2 (SOHO)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	21 Mar 2023	4.2	0.033 AU	0.995 AU	00h02m	+01°55'	1.9°	91.5°	14°
Nearest approach	25 Mar 2023	12.8	0.246 AU	0.951 AU	23h29m	-06°56'	14.2°	93.7°	234°
Today	21 Dec 2025	38.0	18.350 AU	19.059 AU	17h59m	-66°15'	42.8°	2.1°	180°

This comet is a sunskirter. Although it may become very bright at perihelion, this will only be for a very short period very close to the sun.

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 19.0 + 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/2023 F2 (SOHO) are:

    e (Eccentricity)                : 1.0110420
    q (Perihelion distance)         : 0.0334030
    i (Inclination)                 : 72.38880
    Ω (Longitude of ascending node) : 71.43380
    ω (Argument of perihelion)      : 57.57620
    L (Longitude of perihelion)     : 96.90295
    B (Latitude of perihelion)      : 53.56618
    T (Time of perihelion passage)  : 2460024.88010

    Epoch                           : 2025 Dec 21
    Reference                       : MPEC 2023-N01

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-20 00:00 UT   17 58 09.9   -66 15 40    19.054   18.345   42.9    2.1   178   38.0 
2025-12-21 00:00 UT   17 58 41.3   -66 15 40    19.057   18.348   42.8    2.1   179   38.0 
2025-12-21 19:31 UT   17 59 06.8   -66 15 41    19.059   18.350   42.8    2.1   180   38.0 
2025-12-22 00:00 UT   17 59 12.7   -66 15 42    19.060   18.351   42.8    2.1   180   38.0 
2025-12-23 00:00 UT   17 59 44.1   -66 15 46    19.062   18.353   42.8    2.1   182   38.0 
2025-12-24 00:00 UT   18 00 15.4   -66 15 51    19.064   18.356   42.9    2.1   183   38.0 
2025-12-25 00:00 UT   18 00 46.8   -66 15 58    19.066   18.358   42.9    2.1   184   38.0 
2025-12-26 00:00 UT   18 01 18.1   -66 16 07    19.067   18.360   43.0    2.1   186   38.0 
2025-12-27 00:00 UT   18 01 49.4   -66 16 18    19.068   18.362   43.1    2.1   187   38.0 
2025-12-28 00:00 UT   18 02 20.6   -66 16 31    19.069   18.364   43.2    2.1   188   38.0 
2025-12-29 00:00 UT   18 02 51.8   -66 16 45    19.070   18.366   43.3    2.1   189   38.0 
2025-12-30 00:00 UT   18 03 22.9   -66 17 01    19.070   18.368   43.4    2.1   191   38.0 
2025-12-31 00:00 UT   18 03 53.9   -66 17 19    19.070   18.370   43.6    2.1   192   38.0 

    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.