C/2023 F2 (SOHO)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	21 Mar 2023	4.3	0.034 AU	0.994 AU	00h01m	+01°53'	2.0°	91.7°	14°
Nearest approach	25 Mar 2023	12.7	0.244 AU	0.951 AU	23h28m	-06°49'	14.1°	93.8°	234°
Today	15 Sep 2025	37.7	17.617 AU	17.556 AU	17h23m	-68°21'	91.8°	3.3°	93°

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.)

The orbital elements of C/2023 F2 (SOHO) are:

            e (Eccentricity)                : 1.0112990
            q (Perihelion distance)         : 0.0342130
            i (Inclination)                 : 72.45180
            Ω (Longitude of ascending node) : 71.50910
            ω (Argument of perihelion)      : 57.68070
            L (Longitude of perihelion)     : 96.99078
            B (Latitude of perihelion)      : 53.68321
            T (Time of perihelion passage)  : 2460024.66620

            Epoch                           : 2023 Sep 24
            Reference                       : MPEC 2023-N01

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

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 gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (9.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 19.00 + 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
2025-09-15 00:00 UT   17 23 26.2   -68 23 10    17.539   17.609   92.2    3.3    93   37.7 
2025-09-15 17:16 UT   17 23 28.1   -68 21 30    17.556   17.617   91.8    3.3    93   37.7 
2025-09-16 00:00 UT   17 23 28.9   -68 20 51    17.563   17.620   91.6    3.3    94   37.7 
2025-09-17 00:00 UT   17 23 32.2   -68 18 32    17.586   17.632   90.9    3.3    94   37.7 
2025-09-18 00:00 UT   17 23 36.1   -68 16 14    17.610   17.643   90.2    3.3    95   37.7 
2025-09-19 00:00 UT   17 23 40.6   -68 13 57    17.633   17.654   89.5    3.3    96   37.7 
2025-09-20 00:00 UT   17 23 45.6   -68 11 41    17.657   17.665   88.8    3.3    96   37.7 
2025-09-21 00:00 UT   17 23 51.2   -68 09 25    17.680   17.677   88.1    3.3    97   37.7 
2025-09-22 00:00 UT   17 23 57.4   -68 07 10    17.703   17.688   87.4    3.3    98   37.7 
2025-09-23 00:00 UT   17 24 04.2   -68 04 55    17.726   17.699   86.7    3.2    98   37.7 
2025-09-24 00:00 UT   17 24 11.5   -68 02 42    17.749   17.709   86.1    3.2    99   37.7 
2025-09-25 00:00 UT   17 24 19.3   -68 00 29    17.772   17.720   85.4    3.2   100   37.7 

    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.