(11) Parthenope
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	17 Sep 2025	12.3	2.683 AU	3.405 AU	09h14m	+15°49'	37.8°	13.3°
Opposition	25 Feb 2026	10.2	2.689 AU	1.700 AU	10h41m	+12°24'	176.1°	1.4°

The interactive orbit chart above shows the body'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 Parthenope are:

            e (Eccentricity)                : 0.0997989
            a (Semimajor axis)              : 2.4543177
            i (Inclination)                 : 4.63342
            Ω (Longitude of ascending node) : 125.47456
            ω (Argument of perihelion)      : 196.37206
            M (Mean anomaly)                : 122.46023
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 141.79597
            B (Latitude of perihelion)      : -1.30473
            P (Orbital period in years)     : 3.84            
        

The light curve chart below shows the estimated development of the minor planet's magnitude.

The all-sky chart below shows the path of the minor planet over the same period as the light curve. The current position is marked yellow.

The following chart shows the path of the minor planet in the next few days. The field of view is optimized for (~10x50) binoculars and finderscopes. A more printer-friendly version of the same chart can be found below.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-09-17 00:00 UT   09 14 23.3   +15 49 40     3.405    2.683   37.8   13.3   287   12.3 
2025-09-17 12:28 UT   09 15 11.5   +15 46 27     3.401    2.683   38.1   13.4   287   12.3 
2025-09-18 00:00 UT   09 15 56.1   +15 43 29     3.397    2.684   38.4   13.5   287   12.3 
2025-09-19 00:00 UT   09 17 28.6   +15 37 18     3.389    2.684   39.0   13.6   287   12.3 
2025-09-20 00:00 UT   09 19 00.7   +15 31 05     3.381    2.684   39.6   13.8   288   12.3 
2025-09-21 00:00 UT   09 20 32.5   +15 24 51     3.372    2.685   40.2   14.0   288   12.3 
2025-09-22 00:00 UT   09 22 03.9   +15 18 37     3.364    2.685   40.8   14.1   288   12.3 
2025-09-23 00:00 UT   09 23 35.0   +15 12 22     3.355    2.685   41.4   14.3   288   12.3 
2025-09-24 00:00 UT   09 25 05.7   +15 06 06     3.346    2.686   42.0   14.5   288   12.3 
2025-09-25 00:00 UT   09 26 36.1   +14 59 49     3.337    2.686   42.6   14.6   288   12.3 
2025-09-26 00:00 UT   09 28 06.1   +14 53 32     3.328    2.686   43.2   14.8   288   12.3 
2025-09-27 00:00 UT   09 29 35.6   +14 47 14     3.319    2.687   43.8   15.0   288   12.3 
2025-09-28 00:00 UT   09 31 04.9   +14 40 56     3.310    2.687   44.4   15.1   288   12.3 
2025-09-29 00:00 UT   09 32 33.7   +14 34 37     3.300    2.687   45.0   15.3   289   12.3 
2025-09-30 00:00 UT   09 34 02.1   +14 28 18     3.291    2.687   45.6   15.4   289   12.3 
2025-10-01 00:00 UT   09 35 30.2   +14 21 59     3.281    2.688   46.2   15.6   289   12.3 
2025-10-02 00:00 UT   09 36 57.8   +14 15 40     3.272    2.688   46.8   15.8   289   12.3 
2025-10-03 00:00 UT   09 38 25.0   +14 09 20     3.262    2.688   47.5   15.9   289   12.3 
2025-10-04 00:00 UT   09 39 51.9   +14 03 01     3.252    2.689   48.1   16.1   289   12.3 
2025-10-05 00:00 UT   09 41 18.3   +13 56 42     3.242    2.689   48.7   16.2   289   12.3 
2025-10-06 00:00 UT   09 42 44.3   +13 50 23     3.232    2.689   49.3   16.4   289   12.3 
2025-10-07 00:00 UT   09 44 09.9   +13 44 04     3.222    2.690   49.9   16.5   289   12.3 
2025-10-08 00:00 UT   09 45 35.1   +13 37 45     3.211    2.690   50.6   16.7   289   12.3 
2025-10-09 00:00 UT   09 46 59.9   +13 31 27     3.201    2.690   51.2   16.8   290   12.3 

    Terminology:
            
    delta:  distance between minor planet and earth in AU
    radius: distance between minor planet 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-minor planet)    
    phase:  phase angle in degrees (angle sun-minor planet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km
    

Orbital elements provided by 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.