(221) Eos
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	22 Jul 2026	13.1	2.774 AU	2.732 AU	02h31m	+05°26'	81.7°	21.2°
Opposition	31 Oct 2026	11.8	2.855 AU	1.888 AU	02h43m	-01°07'	163.9°	5.5°

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 Eos are:

            e (Eccentricity)                : 0.1008881
            a (Semimajor axis)              : 3.0119012
            i (Inclination)                 : 10.89072
            Ω (Longitude of ascending node) : 141.71100
            ω (Argument of perihelion)      : 192.42898
            M (Mean anomaly)                : 26.70211
            Epoch                           : 2026 Jun 09

            L (Longitude of perihelion)     : 153.92290
            B (Latitude of perihelion)      : -2.33056
            P (Orbital period in years)     : 5.23            
        

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
2026-07-22 00:00 UT   02 31 33.1   +05 26 01     2.732    2.774   81.7   21.2   250   13.1 
2026-07-22 05:30 UT   02 31 47.6   +05 26 15     2.730    2.774   81.8   21.3   250   13.1 
2026-07-23 00:00 UT   02 32 36.0   +05 26 60     2.720    2.774   82.4   21.3   250   13.1 
2026-07-24 00:00 UT   02 33 38.2   +05 27 52     2.708    2.775   83.1   21.3   250   13.1 
2026-07-25 00:00 UT   02 34 39.6   +05 28 36     2.696    2.776   83.8   21.3   251   13.1 
2026-07-26 00:00 UT   02 35 40.2   +05 29 15     2.684    2.776   84.5   21.4   251   13.1 
2026-07-27 00:00 UT   02 36 40.1   +05 29 46     2.672    2.777   85.2   21.4   251   13.1 
2026-07-28 00:00 UT   02 37 39.2   +05 30 10     2.660    2.778   85.9   21.4   251   13.1 
2026-07-29 00:00 UT   02 38 37.5   +05 30 27     2.648    2.779   86.6   21.4   251   13.1 
2026-07-30 00:00 UT   02 39 35.0   +05 30 38     2.636    2.779   87.3   21.4   252   13.1 
2026-07-31 00:00 UT   02 40 31.7   +05 30 41     2.623    2.780   88.0   21.4   252   13.1 
2026-08-01 00:00 UT   02 41 27.6   +05 30 37     2.611    2.781   88.7   21.4   252   13.1 
2026-08-02 00:00 UT   02 42 22.5   +05 30 27     2.599    2.781   89.5   21.4   252   13.0 
2026-08-03 00:00 UT   02 43 16.7   +05 30 09     2.587    2.782   90.2   21.4   252   13.0 
2026-08-04 00:00 UT   02 44 09.9   +05 29 44     2.575    2.783   90.9   21.4   252   13.0 
2026-08-05 00:00 UT   02 45 02.3   +05 29 11     2.563    2.783   91.7   21.4   253   13.0 
2026-08-06 00:00 UT   02 45 53.7   +05 28 32     2.551    2.784   92.4   21.3   253   13.0 
2026-08-07 00:00 UT   02 46 44.2   +05 27 45     2.538    2.785   93.2   21.3   253   13.0 
2026-08-08 00:00 UT   02 47 33.7   +05 26 51     2.526    2.786   93.9   21.3   253   13.0 
2026-08-09 00:00 UT   02 48 22.3   +05 25 50     2.514    2.786   94.7   21.3   253   13.0 
2026-08-10 00:00 UT   02 49 09.9   +05 24 42     2.502    2.787   95.4   21.2   254   13.0 
2026-08-11 00:00 UT   02 49 56.5   +05 23 26     2.490    2.788   96.2   21.2   254   13.0 
2026-08-12 00:00 UT   02 50 42.1   +05 22 02     2.478    2.789   97.0   21.1   254   12.9 
2026-08-13 00:00 UT   02 51 26.6   +05 20 32     2.466    2.789   97.7   21.1   254   12.9 
2026-08-14 00:00 UT   02 52 10.1   +05 18 54     2.454    2.790   98.5   21.0   254   12.9 
2026-08-15 00:00 UT   02 52 52.5   +05 17 09     2.442    2.791   99.3   21.0   255   12.9 
2026-08-16 00:00 UT   02 53 33.9   +05 15 16     2.430    2.791  100.1   20.9   255   12.9 
2026-08-17 00:00 UT   02 54 14.1   +05 13 16     2.418    2.792  100.9   20.9   255   12.9 
2026-08-18 00:00 UT   02 54 53.3   +05 11 09     2.406    2.793  101.7   20.8   255   12.9 
2026-08-19 00:00 UT   02 55 31.3   +05 08 54     2.395    2.794  102.5   20.7   255   12.9 
2026-08-20 00:00 UT   02 56 08.2   +05 06 33     2.383    2.794  103.3   20.6   256   12.8 
2026-08-21 00:00 UT   02 56 43.9   +05 04 04     2.371    2.795  104.1   20.6   256   12.8 

    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.