(106) Dione
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Opposition	22 Jun 2025	12.5	3.393 AU	2.378 AU	18h04m	-26°36'	176.8°	0.9°
Today	2 Jul 2025	12.6	3.381 AU	2.378 AU	17h56m	-26°44'	168.6°	3.4°

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 Dione are:

            e (Eccentricity)                : 0.1589517
            a (Semimajor axis)              : 3.1827157
            i (Inclination)                 : 4.57534
            Ω (Longitude of ascending node) : 61.98647
            ω (Argument of perihelion)      : 331.71391
            M (Mean anomaly)                : 245.25286
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 33.77663
            B (Latitude of perihelion)      : -2.16635
            P (Orbital period in years)     : 5.68            
        

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
2025-07-02 00:00 UT   17 56 07.4   -26 44 10     2.378    3.381  168.6    3.4    74   12.6 
2025-07-02 04:52 UT   17 55 57.2   -26 44 18     2.379    3.381  168.4    3.5    74   12.6 
2025-07-03 00:00 UT   17 55 17.3   -26 44 47     2.380    3.380  167.5    3.7    75   12.7 
2025-07-04 00:00 UT   17 54 27.6   -26 45 20     2.382    3.378  166.4    4.1    77   12.7 
2025-07-05 00:00 UT   17 53 38.5   -26 45 52     2.384    3.377  165.3    4.4    78   12.7 
2025-07-06 00:00 UT   17 52 49.8   -26 46 21     2.386    3.376  164.2    4.7    79   12.7 
2025-07-07 00:00 UT   17 52 01.8   -26 46 47     2.389    3.374  163.1    5.0    80   12.7 
2025-07-08 00:00 UT   17 51 14.4   -26 47 12     2.391    3.373  162.0    5.4    80   12.8 
2025-07-09 00:00 UT   17 50 27.6   -26 47 34     2.395    3.372  160.9    5.7    81   12.8 
2025-07-10 00:00 UT   17 49 41.6   -26 47 53     2.398    3.370  159.8    6.0    82   12.8 
2025-07-11 00:00 UT   17 48 56.3   -26 48 11     2.402    3.369  158.7    6.3    82   12.8 
2025-07-12 00:00 UT   17 48 11.7   -26 48 27     2.406    3.367  157.5    6.6    83   12.8 
2025-07-13 00:00 UT   17 47 28.0   -26 48 40     2.410    3.366  156.4    6.9    83   12.8 
2025-07-14 00:00 UT   17 46 45.1   -26 48 52     2.414    3.365  155.3    7.2    84   12.9 
2025-07-15 00:00 UT   17 46 03.2   -26 49 01     2.419    3.363  154.2    7.5    84   12.9 
2025-07-16 00:00 UT   17 45 22.1   -26 49 09     2.424    3.362  153.1    7.8    85   12.9 
2025-07-17 00:00 UT   17 44 42.0   -26 49 15     2.429    3.361  152.0    8.1    85   12.9 
2025-07-18 00:00 UT   17 44 02.9   -26 49 20     2.434    3.359  151.0    8.4    85   12.9 
2025-07-19 00:00 UT   17 43 24.8   -26 49 23     2.440    3.358  149.9    8.7    86   12.9 
2025-07-20 00:00 UT   17 42 47.7   -26 49 24     2.446    3.357  148.8    9.0    86   13.0 
2025-07-21 00:00 UT   17 42 11.7   -26 49 24     2.452    3.355  147.7    9.3    86   13.0 
2025-07-22 00:00 UT   17 41 36.9   -26 49 22     2.459    3.354  146.6    9.6    87   13.0 
2025-07-23 00:00 UT   17 41 03.2   -26 49 20     2.465    3.353  145.5    9.9    87   13.0 
2025-07-24 00:00 UT   17 40 30.6   -26 49 16     2.472    3.351  144.5   10.1    87   13.0 
2025-07-25 00:00 UT   17 39 59.2   -26 49 11     2.479    3.350  143.4   10.4    87   13.0 
2025-07-26 00:00 UT   17 39 29.1   -26 49 05     2.486    3.348  142.3   10.7    88   13.1 
2025-07-27 00:00 UT   17 39 00.2   -26 48 58     2.494    3.347  141.3   10.9    88   13.1 
2025-07-28 00:00 UT   17 38 32.6   -26 48 50     2.501    3.346  140.2   11.2    88   13.1 
2025-07-29 00:00 UT   17 38 06.2   -26 48 41     2.509    3.344  139.2   11.4    88   13.1 
2025-07-30 00:00 UT   17 37 41.1   -26 48 32     2.517    3.343  138.1   11.7    88   13.1 
2025-07-31 00:00 UT   17 37 17.3   -26 48 22     2.526    3.342  137.1   11.9    89   13.1 
2025-08-01 00:00 UT   17 36 54.9   -26 48 11     2.534    3.340  136.1   12.2    89   13.1 

    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.