(221) Eos
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	17 Oct 2026	11.9	2.842 AU	1.900 AU	02h53m	+00°10'	156.4°	8.1°
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
2026-10-17 00:00 UT   02 53 48.5   +00 10 34     1.900    2.842  156.4    8.1   293   11.9 
2026-10-17 06:05 UT   02 53 38.4   +00 09 02     1.900    2.842  156.7    8.0   293   11.9 
2026-10-18 00:00 UT   02 53 08.4   +00 04 34     1.898    2.843  157.3    7.8   295   11.9 
2026-10-19 00:00 UT   02 52 27.5   +00 01 22     1.895    2.844  158.1    7.5   297   11.9 
2026-10-20 00:00 UT   02 51 45.8   +00 07 13     1.893    2.845  158.8    7.3   300   11.9 
2026-10-21 00:00 UT   02 51 03.3   +00 12 60     1.891    2.846  159.6    7.0   302   11.9 
2026-10-22 00:00 UT   02 50 20.2   +00 18 41     1.890    2.846  160.3    6.8   305   11.9 
2026-10-23 00:00 UT   02 49 36.5   +00 24 17     1.888    2.847  160.9    6.6   308   11.9 
2026-10-24 00:00 UT   02 48 52.1   +00 29 47     1.887    2.848  161.5    6.4   311   11.8 
2026-10-25 00:00 UT   02 48 07.3   +00 35 10     1.886    2.849  162.1    6.2   315   11.8 
2026-10-26 00:00 UT   02 47 21.9   +00 40 28     1.886    2.850  162.6    6.0   318   11.8 
2026-10-27 00:00 UT   02 46 36.1   +00 45 38     1.886    2.851  163.0    5.9   322   11.8 
2026-10-28 00:00 UT   02 45 49.9   +00 50 41     1.886    2.852  163.3    5.7   326   11.8 
2026-10-29 00:00 UT   02 45 03.4   +00 55 37     1.886    2.853  163.6    5.6   330   11.8 
2026-10-30 00:00 UT   02 44 16.6   -01 00 25     1.886    2.854  163.8    5.6   334   11.8 
2026-10-31 00:00 UT   02 43 29.6   -01 05 05     1.887    2.854  163.9    5.5   339   11.8 
2026-11-01 00:00 UT   02 42 42.4   -01 09 36     1.888    2.855  163.9    5.5   343   11.8 
2026-11-02 00:00 UT   02 41 55.1   -01 13 59     1.890    2.856  163.8    5.6   347   11.8 
2026-11-03 00:00 UT   02 41 07.7   -01 18 13     1.892    2.857  163.6    5.6   351   11.8 
2026-11-04 00:00 UT   02 40 20.3   -01 22 17     1.893    2.858  163.4    5.7   356   11.8 
2026-11-05 00:00 UT   02 39 33.0   -01 26 12     1.896    2.859  163.1    5.8   360   11.8 
2026-11-06 00:00 UT   02 38 45.7   -01 29 58     1.898    2.860  162.7    5.9     3   11.9 
2026-11-07 00:00 UT   02 37 58.6   -01 33 33     1.901    2.861  162.2    6.1     7   11.9 
2026-11-08 00:00 UT   02 37 11.8   -01 36 58     1.904    2.862  161.7    6.3    11   11.9 
2026-11-09 00:00 UT   02 36 25.2   -01 40 13     1.907    2.863  161.1    6.4    14   11.9 
2026-11-10 00:00 UT   02 35 38.9   -01 43 17     1.911    2.864  160.4    6.7    17   11.9 
2026-11-11 00:00 UT   02 34 53.0   -01 46 10     1.915    2.865  159.7    6.9    20   11.9 
2026-11-12 00:00 UT   02 34 07.5   -01 48 52     1.919    2.865  159.0    7.1    22   11.9 
2026-11-13 00:00 UT   02 33 22.6   -01 51 23     1.923    2.866  158.2    7.4    25   12.0 
2026-11-14 00:00 UT   02 32 38.2   -01 53 43     1.928    2.867  157.4    7.6    27   12.0 
2026-11-15 00:00 UT   02 31 54.3   -01 55 51     1.933    2.868  156.6    7.9    29   12.0 
2026-11-16 00:00 UT   02 31 11.1   -01 57 48     1.938    2.869  155.8    8.1    31   12.0 

    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.