(259) Aletheia
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	17 Sep 2025	13.2	2.749 AU	2.742 AU	16h49m	-24°00'	79.8°	21.1°
Opposition	11 Sep 2026	12.4	3.121 AU	2.140 AU	23h44m	-18°51'	164.3°	5.0°

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 Aletheia are:

            e (Eccentricity)                : 0.1299692
            a (Semimajor axis)              : 3.1335320
            i (Inclination)                 : 10.80839
            Ω (Longitude of ascending node) : 86.78060
            ω (Argument of perihelion)      : 166.32872
            M (Mean anomaly)                : 28.43028
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 73.34298
            B (Latitude of perihelion)      : 2.54028
            P (Orbital period in years)     : 5.55            
        

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   16 49 06.0   -24 00 30     2.742    2.749   79.8   21.1    97   13.2 
2025-09-17 19:49 UT   16 50 06.1   -24 03 55     2.753    2.750   79.3   21.0    97   13.2 
2025-09-18 00:00 UT   16 50 18.9   -24 04 38     2.756    2.750   79.1   21.0    97   13.2 
2025-09-19 00:00 UT   16 51 32.6   -24 08 44     2.769    2.750   78.5   21.0    97   13.2 
2025-09-20 00:00 UT   16 52 47.2   -24 12 48     2.782    2.751   77.8   20.9    97   13.3 
2025-09-21 00:00 UT   16 54 02.6   -24 16 49     2.796    2.751   77.1   20.8    97   13.3 
2025-09-22 00:00 UT   16 55 18.9   -24 20 49     2.809    2.752   76.4   20.8    97   13.3 
2025-09-23 00:00 UT   16 56 35.9   -24 24 46     2.822    2.752   75.7   20.7    97   13.3 
2025-09-24 00:00 UT   16 57 53.8   -24 28 41     2.835    2.753   75.0   20.6    97   13.3 
2025-09-25 00:00 UT   16 59 12.5   -24 32 34     2.848    2.753   74.4   20.5    97   13.3 
2025-09-26 00:00 UT   17 00 31.9   -24 36 24     2.862    2.754   73.7   20.5    96   13.3 
2025-09-27 00:00 UT   17 01 52.1   -24 40 11     2.875    2.754   73.0   20.4    96   13.3 
2025-09-28 00:00 UT   17 03 13.0   -24 43 56     2.888    2.755   72.4   20.3    96   13.3 
2025-09-29 00:00 UT   17 04 34.7   -24 47 38     2.901    2.755   71.7   20.2    96   13.3 
2025-09-30 00:00 UT   17 05 57.1   -24 51 17     2.914    2.756   71.0   20.1    96   13.3 
2025-10-01 00:00 UT   17 07 20.3   -24 54 54     2.927    2.756   70.4   20.0    96   13.3 
2025-10-02 00:00 UT   17 08 44.1   -24 58 27     2.939    2.757   69.7   19.9    96   13.4 
2025-10-03 00:00 UT   17 10 08.7   -25 01 58     2.952    2.757   69.0   19.8    96   13.4 
2025-10-04 00:00 UT   17 11 33.9   -25 05 26     2.965    2.758   68.4   19.7    96   13.4 
2025-10-05 00:00 UT   17 12 59.8   -25 08 50     2.978    2.759   67.7   19.6    96   13.4 
2025-10-06 00:00 UT   17 14 26.3   -25 12 12     2.990    2.759   67.1   19.5    95   13.4 
2025-10-07 00:00 UT   17 15 53.5   -25 15 30     3.003    2.760   66.4   19.4    95   13.4 
2025-10-08 00:00 UT   17 17 21.3   -25 18 45     3.016    2.760   65.8   19.3    95   13.4 
2025-10-09 00:00 UT   17 18 49.8   -25 21 57     3.028    2.761   65.1   19.2    95   13.4 
2025-10-10 00:00 UT   17 20 18.9   -25 25 06     3.041    2.761   64.5   19.0    95   13.4 
2025-10-11 00:00 UT   17 21 48.6   -25 28 11     3.053    2.762   63.8   18.9    95   13.4 
2025-10-12 00:00 UT   17 23 18.9   -25 31 12     3.065    2.763   63.2   18.8    95   13.4 
2025-10-13 00:00 UT   17 24 49.8   -25 34 10     3.078    2.763   62.5   18.7    95   13.4 

    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.