(17) Thetis
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	17 Sep 2025	13.5	2.797 AU	2.882 AU	06h38m	+19°10'	75.1°	20.3°
Opposition	30 Dec 2025	11.6	2.777 AU	1.795 AU	06h40m	+19°15'	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 Thetis are:

            e (Eccentricity)                : 0.1319544
            a (Semimajor axis)              : 2.4711982
            i (Inclination)                 : 5.59241
            Ω (Longitude of ascending node) : 125.52278
            ω (Argument of perihelion)      : 135.78159
            M (Mean anomaly)                : 142.11870
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 81.44099
            B (Latitude of perihelion)      : 3.89694
            P (Orbital period in years)     : 3.88            
        

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   06 38 02.1   +19 10 30     2.882    2.797   75.1   20.3   273   13.5 
2025-09-17 13:55 UT   06 38 40.2   +19 09 42     2.874    2.797   75.5   20.4   273   13.5 
2025-09-18 00:00 UT   06 39 07.6   +19 09 07     2.869    2.797   75.8   20.4   273   13.5 
2025-09-19 00:00 UT   06 40 12.4   +19 07 44     2.856    2.797   76.5   20.4   273   13.4 
2025-09-20 00:00 UT   06 41 16.3   +19 06 19     2.842    2.797   77.2   20.5   273   13.4 
2025-09-21 00:00 UT   06 42 19.4   +19 04 53     2.829    2.797   77.9   20.6   273   13.4 
2025-09-22 00:00 UT   06 43 21.6   +19 03 26     2.816    2.797   78.7   20.6   273   13.4 
2025-09-23 00:00 UT   06 44 23.0   +19 01 59     2.802    2.797   79.4   20.6   274   13.4 
2025-09-24 00:00 UT   06 45 23.5   +19 00 30     2.789    2.797   80.1   20.7   274   13.4 
2025-09-25 00:00 UT   06 46 23.2   +18 59 01     2.775    2.797   80.9   20.7   274   13.4 
2025-09-26 00:00 UT   06 47 21.9   +18 57 31     2.762    2.797   81.6   20.8   274   13.4 
2025-09-27 00:00 UT   06 48 19.8   +18 56 01     2.748    2.797   82.4   20.8   274   13.4 
2025-09-28 00:00 UT   06 49 16.7   +18 54 30     2.734    2.797   83.1   20.8   274   13.4 
2025-09-29 00:00 UT   06 50 12.7   +18 52 59     2.721    2.797   83.9   20.9   275   13.4 
2025-09-30 00:00 UT   06 51 07.7   +18 51 28     2.707    2.797   84.6   20.9   275   13.3 
2025-10-01 00:00 UT   06 52 01.8   +18 49 57     2.693    2.797   85.4   20.9   275   13.3 
2025-10-02 00:00 UT   06 52 54.9   +18 48 25     2.680    2.797   86.2   20.9   275   13.3 
2025-10-03 00:00 UT   06 53 47.0   +18 46 54     2.666    2.797   86.9   20.9   275   13.3 
2025-10-04 00:00 UT   06 54 38.1   +18 45 22     2.652    2.797   87.7   20.9   275   13.3 
2025-10-05 00:00 UT   06 55 28.1   +18 43 51     2.638    2.797   88.5   20.9   275   13.3 
2025-10-06 00:00 UT   06 56 17.2   +18 42 20     2.625    2.797   89.3   20.9   276   13.3 
2025-10-07 00:00 UT   06 57 05.1   +18 40 50     2.611    2.797   90.1   20.9   276   13.3 
2025-10-08 00:00 UT   06 57 52.1   +18 39 20     2.597    2.797   90.9   20.9   276   13.3 
2025-10-09 00:00 UT   06 58 37.9   +18 37 50     2.583    2.797   91.7   20.9   276   13.2 
2025-10-10 00:00 UT   06 59 22.6   +18 36 21     2.570    2.797   92.5   20.9   276   13.2 
2025-10-11 00:00 UT   07 00 06.2   +18 34 53     2.556    2.797   93.3   20.9   276   13.2 
2025-10-12 00:00 UT   07 00 48.7   +18 33 26     2.542    2.797   94.1   20.9   276   13.2 
2025-10-13 00:00 UT   07 01 30.0   +18 32 00     2.528    2.797   94.9   20.8   276   13.2 
2025-10-14 00:00 UT   07 02 10.1   +18 30 35     2.515    2.797   95.8   20.8   277   13.2 
2025-10-15 00:00 UT   07 02 49.0   +18 29 11     2.501    2.797   96.6   20.7   277   13.2 
2025-10-16 00:00 UT   07 03 26.8   +18 27 49     2.487    2.797   97.4   20.7   277   13.2 
2025-10-17 00:00 UT   07 04 03.2   +18 26 27     2.473    2.797   98.3   20.7   277   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.