(404) Arsinoe
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Opposition	30 Aug 2025	13.2	2.812 AU	1.841 AU	23h09m	-27°00'	160.2°	7.0°
Today	24 Oct 2025	14.1	2.903 AU	2.299 AU	22h35m	-27°35'	118.1°	17.6°

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 Arsinoe are:

            e (Eccentricity)                : 0.2016098
            a (Semimajor axis)              : 2.5918971
            i (Inclination)                 : 14.09820
            Ω (Longitude of ascending node) : 92.46743
            ω (Argument of perihelion)      : 120.51372
            M (Mean anomaly)                : 123.86510
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 33.75326
            B (Latitude of perihelion)      : 12.11356
            P (Orbital period in years)     : 4.17            
        

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.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-10-24 00:00 UT   22 35 45.6   -27 35 42     2.299    2.903  118.1   17.6    58   14.1 
2025-10-24 08:18 UT   22 35 44.9   -27 33 59     2.303    2.904  117.8   17.6    58   14.1 
2025-10-25 00:00 UT   22 35 44.2   -27 30 40     2.312    2.905  117.2   17.7    58   14.2 
2025-10-26 00:00 UT   22 35 44.2   -27 25 28     2.325    2.906  116.3   17.9    58   14.2 
2025-10-27 00:00 UT   22 35 45.8   -27 20 09     2.339    2.908  115.4   18.0    59   14.2 
2025-10-28 00:00 UT   22 35 48.7   -27 14 41     2.352    2.909  114.5   18.1    59   14.2 
2025-10-29 00:00 UT   22 35 53.1   -27 09 06     2.366    2.911  113.6   18.2    59   14.2 
2025-10-30 00:00 UT   22 35 59.0   -27 03 22     2.380    2.912  112.8   18.3    60   14.2 
2025-10-31 00:00 UT   22 36 06.2   -26 57 31     2.394    2.914  111.9   18.4    60   14.3 
2025-11-01 00:00 UT   22 36 14.8   -26 51 33     2.408    2.915  111.0   18.5    61   14.3 
2025-11-02 00:00 UT   22 36 24.8   -26 45 28     2.422    2.917  110.1   18.6    61   14.3 
2025-11-03 00:00 UT   22 36 36.2   -26 39 15     2.436    2.918  109.3   18.7    61   14.3 
2025-11-04 00:00 UT   22 36 48.9   -26 32 57     2.450    2.920  108.4   18.8    62   14.3 
2025-11-05 00:00 UT   22 37 02.9   -26 26 31     2.465    2.921  107.6   18.9    62   14.4 
2025-11-06 00:00 UT   22 37 18.2   -26 19 59     2.479    2.923  106.7   19.0    62   14.4 
2025-11-07 00:00 UT   22 37 34.8   -26 13 21     2.494    2.924  105.9   19.0    62   14.4 
2025-11-08 00:00 UT   22 37 52.7   -26 06 37     2.508    2.926  105.0   19.1    63   14.4 
2025-11-09 00:00 UT   22 38 11.9   -25 59 47     2.523    2.927  104.2   19.2    63   14.4 
2025-11-10 00:00 UT   22 38 32.3   -25 52 51     2.537    2.929  103.3   19.2    63   14.4 
2025-11-11 00:00 UT   22 38 53.9   -25 45 49     2.552    2.930  102.5   19.3    64   14.4 
2025-11-12 00:00 UT   22 39 16.7   -25 38 42     2.567    2.931  101.6   19.3    64   14.5 
2025-11-13 00:00 UT   22 39 40.8   -25 31 30     2.581    2.933  100.8   19.4    64   14.5 
2025-11-14 00:00 UT   22 40 06.0   -25 24 12     2.596    2.934  100.0   19.4    64   14.5 
2025-11-15 00:00 UT   22 40 32.4   -25 16 49     2.611    2.936   99.2   19.4    65   14.5 
2025-11-16 00:00 UT   22 40 59.9   -25 09 21     2.626    2.937   98.3   19.5    65   14.5 
2025-11-17 00:00 UT   22 41 28.5   -25 01 48     2.641    2.939   97.5   19.5    65   14.5 
2025-11-18 00:00 UT   22 41 58.3   -24 54 11     2.656    2.940   96.7   19.5    65   14.5 
2025-11-19 00:00 UT   22 42 29.2   -24 46 29     2.671    2.941   95.9   19.5    65   14.6 
2025-11-20 00:00 UT   22 43 01.2   -24 38 42     2.686    2.943   95.1   19.5    66   14.6 
2025-11-21 00:00 UT   22 43 34.2   -24 30 51     2.701    2.944   94.3   19.6    66   14.6 
2025-11-22 00:00 UT   22 44 08.3   -24 22 55     2.716    2.946   93.5   19.6    66   14.6 
2025-11-23 00:00 UT   22 44 43.4   -24 14 55     2.731    2.947   92.7   19.6    66   14.6 

    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.