(259) Aletheia
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Opposition	31 May 2025	11.4	2.727 AU	1.715 AU	16h38m	-17°07'	175.0°	1.8°
Today	20 Jun 2025	11.8	2.726 AU	1.758 AU	16h22m	-17°56'	157.9°	8.1°

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 Aletheia are:

            e (Eccentricity)                : 0.1299188
            a (Semimajor axis)              : 3.1334338
            i (Inclination)                 : 10.80855
            Ω (Longitude of ascending node) : 86.78078
            ω (Argument of perihelion)      : 166.37237
            M (Mean anomaly)                : 352.85984
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 73.38613
            B (Latitude of perihelion)      : 2.53236
            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
2025-06-20 00:00 UT   16 22 05.2   -17 56 28     1.758    2.726  157.9    8.1   108   11.8 
2025-06-20 07:13 UT   16 21 52.2   -17 57 20     1.760    2.726  157.6    8.2   108   11.8 
2025-06-21 00:00 UT   16 21 22.4   -17 59 22     1.763    2.726  156.8    8.4   108   11.8 
2025-06-22 00:00 UT   16 20 40.7   -18 02 18     1.768    2.726  155.7    8.8   107   11.8 
2025-06-23 00:00 UT   16 20 00.1   -18 05 17     1.773    2.727  154.6    9.2   107   11.9 
2025-06-24 00:00 UT   16 19 20.6   -18 08 17     1.779    2.727  153.5    9.6   106   11.9 
2025-06-25 00:00 UT   16 18 42.3   -18 11 20     1.785    2.727  152.5    9.9   106   11.9 
2025-06-26 00:00 UT   16 18 05.2   -18 14 26     1.791    2.727  151.4   10.3   106   11.9 
2025-06-27 00:00 UT   16 17 29.3   -18 17 34     1.797    2.727  150.3   10.6   105   11.9 
2025-06-28 00:00 UT   16 16 54.7   -18 20 44     1.803    2.727  149.2   11.0   105   12.0 
2025-06-29 00:00 UT   16 16 21.4   -18 23 56     1.810    2.727  148.2   11.3   105   12.0 
2025-06-30 00:00 UT   16 15 49.5   -18 27 11     1.817    2.727  147.1   11.7   104   12.0 
2025-07-01 00:00 UT   16 15 18.9   -18 30 28     1.824    2.727  146.1   12.0   104   12.0 
2025-07-02 00:00 UT   16 14 49.8   -18 33 48     1.831    2.727  145.0   12.3   104   12.0 
2025-07-03 00:00 UT   16 14 22.1   -18 37 10     1.839    2.727  144.0   12.7   104   12.1 
2025-07-04 00:00 UT   16 13 55.8   -18 40 34     1.846    2.727  142.9   13.0   104   12.1 
2025-07-05 00:00 UT   16 13 30.9   -18 44 01     1.854    2.727  141.9   13.3   103   12.1 
2025-07-06 00:00 UT   16 13 07.5   -18 47 30     1.862    2.728  140.9   13.6   103   12.1 
2025-07-07 00:00 UT   16 12 45.7   -18 51 01     1.871    2.728  139.9   13.9   103   12.2 
2025-07-08 00:00 UT   16 12 25.3   -18 54 35     1.879    2.728  138.8   14.2   103   12.2 
2025-07-09 00:00 UT   16 12 06.4   -18 58 10     1.888    2.728  137.8   14.5   103   12.2 
2025-07-10 00:00 UT   16 11 49.0   -19 01 48     1.897    2.728  136.8   14.8   103   12.2 
2025-07-11 00:00 UT   16 11 33.2   -19 05 29     1.906    2.728  135.8   15.0   102   12.2 
2025-07-12 00:00 UT   16 11 18.9   -19 09 11     1.915    2.728  134.8   15.3   102   12.3 
2025-07-13 00:00 UT   16 11 06.2   -19 12 56     1.924    2.728  133.8   15.6   102   12.3 
2025-07-14 00:00 UT   16 10 55.0   -19 16 43     1.934    2.729  132.9   15.8   102   12.3 
2025-07-15 00:00 UT   16 10 45.3   -19 20 31     1.943    2.729  131.9   16.1   102   12.3 
2025-07-16 00:00 UT   16 10 37.2   -19 24 22     1.953    2.729  130.9   16.3   102   12.3 
2025-07-17 00:00 UT   16 10 30.7   -19 28 16     1.963    2.729  129.9   16.6   102   12.4 
2025-07-18 00:00 UT   16 10 25.7   -19 32 11     1.973    2.729  129.0   16.8   102   12.4 
2025-07-19 00:00 UT   16 10 22.2   -19 36 08     1.983    2.729  128.0   17.1   102   12.4 
2025-07-20 00:00 UT   16 10 20.4   -19 40 07     1.994    2.730  127.1   17.3   102   12.4 

    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.