(113) Amalthea
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	5 Jul 2025	12.7	2.191 AU	1.764 AU	13h35m	-03°32'	100.5°	27.1°
Opposition	11 Sep 2026	11.8	2.538 AU	1.535 AU	23h29m	-09°47'	174.0°	2.4°

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 Amalthea are:

            e (Eccentricity)                : 0.0860520
            a (Semimajor axis)              : 2.3762273
            i (Inclination)                 : 5.04231
            Ω (Longitude of ascending node) : 123.32434
            ω (Argument of perihelion)      : 80.23807
            M (Mean anomaly)                : 6.41686
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 203.52522
            B (Latitude of perihelion)      : 4.96912
            P (Orbital period in years)     : 3.66            
        

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
2025-07-05 00:00 UT   13 35 38.2   -03 32 45     1.764    2.191  100.5   27.1   113   12.7 
2025-07-05 18:21 UT   13 36 18.9   -03 39 05     1.773    2.191  100.0   27.2   112   12.7 
2025-07-06 00:00 UT   13 36 31.5   -03 41 03     1.776    2.191   99.8   27.2   112   12.7 
2025-07-07 00:00 UT   13 37 26.0   -03 49 25     1.787    2.192   99.1   27.3   112   12.7 
2025-07-08 00:00 UT   13 38 21.6   -03 57 52     1.799    2.192   98.4   27.3   112   12.7 
2025-07-09 00:00 UT   13 39 18.2   -04 06 24     1.810    2.193   97.8   27.3   112   12.8 
2025-07-10 00:00 UT   13 40 16.0   -04 14 59     1.822    2.193   97.1   27.4   112   12.8 
2025-07-11 00:00 UT   13 41 14.8   -04 23 38     1.833    2.193   96.4   27.4   112   12.8 
2025-07-12 00:00 UT   13 42 14.7   -04 32 21     1.845    2.194   95.8   27.5   112   12.8 
2025-07-13 00:00 UT   13 43 15.6   -04 41 07     1.857    2.194   95.1   27.5   112   12.8 
2025-07-14 00:00 UT   13 44 17.6   -04 49 57     1.868    2.195   94.4   27.5   111   12.8 
2025-07-15 00:00 UT   13 45 20.5   -04 58 51     1.880    2.195   93.8   27.5   111   12.8 
2025-07-16 00:00 UT   13 46 24.5   -05 07 47     1.892    2.196   93.1   27.5   111   12.9 
2025-07-17 00:00 UT   13 47 29.4   -05 16 47     1.903    2.196   92.5   27.5   111   12.9 
2025-07-18 00:00 UT   13 48 35.3   -05 25 50     1.915    2.197   91.9   27.5   111   12.9 
2025-07-19 00:00 UT   13 49 42.1   -05 34 55     1.927    2.197   91.2   27.5   111   12.9 
2025-07-20 00:00 UT   13 50 49.9   -05 44 04     1.939    2.198   90.6   27.5   111   12.9 
2025-07-21 00:00 UT   13 51 58.6   -05 53 15     1.950    2.198   90.0   27.5   111   12.9 
2025-07-22 00:00 UT   13 53 08.3   -06 02 28     1.962    2.199   89.3   27.5   111   12.9 
2025-07-23 00:00 UT   13 54 18.8   -06 11 44     1.974    2.199   88.7   27.5   110   13.0 
2025-07-24 00:00 UT   13 55 30.3   -06 21 02     1.986    2.200   88.1   27.5   110   13.0 
2025-07-25 00:00 UT   13 56 42.6   -06 30 22     1.997    2.200   87.5   27.5   110   13.0 
2025-07-26 00:00 UT   13 57 55.9   -06 39 44     2.009    2.201   86.9   27.4   110   13.0 
2025-07-27 00:00 UT   13 59 09.9   -06 49 08     2.021    2.202   86.2   27.4   110   13.0 
2025-07-28 00:00 UT   14 00 24.9   -06 58 34     2.033    2.202   85.6   27.4   110   13.0 
2025-07-29 00:00 UT   14 01 40.7   -07 08 02     2.045    2.203   85.0   27.3   110   13.0 
2025-07-30 00:00 UT   14 02 57.3   -07 17 30     2.056    2.203   84.4   27.3   110   13.0 
2025-07-31 00:00 UT   14 04 14.7   -07 27 01     2.068    2.204   83.8   27.3   109   13.1 
2025-08-01 00:00 UT   14 05 32.9   -07 36 32     2.080    2.204   83.2   27.2   109   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.