P/2024 FG9 (Nanshan-Hahn)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	8 Dec 2023	17.9	2.189 AU	1.262 AU	03h05m	+18°05'	153.6°	11.5°	75°
Perihelion	20 May 2024	17.6	1.596 AU	2.043 AU	07h25m	+20°44'	50.2°	29.1°	99°
Today	30 May 2026	23.6	4.567 AU	3.964 AU	20h39m	-16°59'	120.9°	11.0°	254°

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. 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. (14.0 + 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 P/2024 FG9 (Nanshan-Hahn) are:

    e (Eccentricity)                : 0.5100220
    q (Perihelion distance)         : 1.5964660
    i (Inclination)                 : 1.73080
    Ω (Longitude of ascending node) : 253.03340
    ω (Argument of perihelion)      : 245.96380
    L (Longitude of perihelion)     : 318.98747
    B (Latitude of perihelion)      : -1.58068
    T (Time of perihelion passage)  : 2460451.05930
    P (Orbital period in years)     : 5.88

    Epoch                           : 2026 May 29
    Reference                       : MPC194189

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.958

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-05-29 00:00 UT   20 39 28.1   -16 59 22     3.980    4.564  119.5   11.1   254   23.6 
2026-05-30 00:00 UT   20 39 17.2   -16 59 40     3.968    4.567  120.5   11.0   254   23.6 
2026-05-30 09:45 UT   20 39 12.5   -16 59 48     3.964    4.567  120.9   11.0   254   23.6 
2026-05-31 00:00 UT   20 39 05.3   -17 00 00     3.957    4.569  121.5   10.9   254   23.6 
2026-06-01 00:00 UT   20 38 52.6   -17 00 25     3.946    4.571  122.5   10.8   254   23.6 
2026-06-02 00:00 UT   20 38 38.9   -17 00 52     3.934    4.573  123.5   10.7   254   23.6 
2026-06-03 00:00 UT   20 38 24.3   -17 01 23     3.923    4.575  124.5   10.5   254   23.6 
2026-06-04 00:00 UT   20 38 08.8   -17 01 58     3.913    4.577  125.5   10.4   254   23.6 
2026-06-05 00:00 UT   20 37 52.4   -17 02 36     3.902    4.579  126.6   10.3   254   23.6 
2026-06-06 00:00 UT   20 37 35.0   -17 03 17     3.891    4.581  127.6   10.1   254   23.6 
2026-06-07 00:00 UT   20 37 16.8   -17 04 02     3.881    4.583  128.6   10.0   254   23.6 
2026-06-08 00:00 UT   20 36 57.7   -17 04 50     3.871    4.586  129.6    9.8   254   23.6 
2026-06-09 00:00 UT   20 36 37.7   -17 05 41     3.861    4.588  130.7    9.7   254   23.5 

    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.