(423) Diotima
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Opposition	14 Nov 2025	11.7	3.149 AU	2.162 AU	03h23m	+13°29'	175.1°	1.6°
Today	13 Dec 2025	12.3	3.154 AU	2.291 AU	03h01m	+13°36'	145.8°	10.1°

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 Diotima are:

            e (Eccentricity)                : 0.0338729
            a (Semimajor axis)              : 3.0667835
            i (Inclination)                 : 11.24258
            Ω (Longitude of ascending node) : 69.34900
            ω (Argument of perihelion)      : 199.08736
            M (Mean anomaly)                : 142.07248
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 88.09589
            B (Latitude of perihelion)      : -3.65536
            P (Orbital period in years)     : 5.37            
        

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.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-13 00:00 UT   03 01 15.6   +13 36 20     2.291    3.154  145.8   10.1    69   12.3 
2025-12-13 05:07 UT   03 01 08.3   +13 36 35     2.293    3.154  145.5   10.2    69   12.3 
2025-12-14 00:00 UT   03 00 41.7   +13 37 32     2.299    3.154  144.7   10.4    69   12.3 
2025-12-15 00:00 UT   03 00 09.1   +13 38 48     2.308    3.154  143.5   10.7    69   12.4 
2025-12-16 00:00 UT   02 59 37.6   +13 40 09     2.317    3.155  142.4   11.0    69   12.4 
2025-12-17 00:00 UT   02 59 07.5   +13 41 35     2.326    3.155  141.3   11.3    70   12.4 
2025-12-18 00:00 UT   02 58 38.6   +13 43 06     2.336    3.155  140.2   11.5    70   12.4 
2025-12-19 00:00 UT   02 58 11.1   +13 44 41     2.345    3.155  139.1   11.8    70   12.4 
2025-12-20 00:00 UT   02 57 44.8   +13 46 22     2.355    3.155  137.9   12.1    70   12.5 
2025-12-21 00:00 UT   02 57 19.9   +13 48 07     2.365    3.155  136.8   12.3    70   12.5 
2025-12-22 00:00 UT   02 56 56.4   +13 49 57     2.375    3.156  135.8   12.6    70   12.5 
2025-12-23 00:00 UT   02 56 34.2   +13 51 53     2.386    3.156  134.7   12.8    71   12.5 
2025-12-24 00:00 UT   02 56 13.4   +13 53 53     2.396    3.156  133.6   13.0    71   12.5 
2025-12-25 00:00 UT   02 55 53.9   +13 55 58     2.407    3.156  132.5   13.3    71   12.6 
2025-12-26 00:00 UT   02 55 35.9   +13 58 08     2.418    3.156  131.4   13.5    71   12.6 
2025-12-27 00:00 UT   02 55 19.2   +14 00 23     2.429    3.156  130.4   13.7    71   12.6 
2025-12-28 00:00 UT   02 55 04.0   +14 02 43     2.441    3.157  129.3   14.0    71   12.6 
2025-12-29 00:00 UT   02 54 50.1   +14 05 07     2.452    3.157  128.2   14.2    71   12.6 
2025-12-30 00:00 UT   02 54 37.7   +14 07 37     2.464    3.157  127.2   14.4    71   12.6 
2025-12-31 00:00 UT   02 54 26.6   +14 10 11     2.476    3.157  126.1   14.6    72   12.7 
2026-01-01 00:00 UT   02 54 17.0   +14 12 51     2.488    3.157  125.1   14.8    72   12.7 
2026-01-02 00:00 UT   02 54 08.7   +14 15 34     2.500    3.157  124.1   15.0    72   12.7 
2026-01-03 00:00 UT   02 54 01.8   +14 18 23     2.512    3.158  123.0   15.1    72   12.7 
2026-01-04 00:00 UT   02 53 56.3   +14 21 16     2.524    3.158  122.0   15.3    72   12.7 
2026-01-05 00:00 UT   02 53 52.2   +14 24 14     2.537    3.158  121.0   15.5    72   12.7 
2026-01-06 00:00 UT   02 53 49.5   +14 27 16     2.550    3.158  120.0   15.6    72   12.8 
2026-01-07 00:00 UT   02 53 48.1   +14 30 23     2.562    3.158  119.0   15.8    72   12.8 
2026-01-08 00:00 UT   02 53 48.1   +14 33 35     2.575    3.158  118.0   16.0    72   12.8 
2026-01-09 00:00 UT   02 53 49.5   +14 36 51     2.588    3.158  117.0   16.1    72   12.8 
2026-01-10 00:00 UT   02 53 52.2   +14 40 11     2.602    3.159  116.0   16.3    72   12.8 
2026-01-11 00:00 UT   02 53 56.3   +14 43 36     2.615    3.159  115.0   16.4    72   12.8 
2026-01-12 00:00 UT   02 54 01.7   +14 47 05     2.628    3.159  114.0   16.5    72   12.9 

    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.