(221) Eos
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	21 Aug 2026	12.8	2.795 AU	2.371 AU	02h56m	+05°04'	104.1°	20.6°
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
2026-08-21 00:00 UT   02 56 43.9   +05 04 04     2.371    2.795  104.1   20.6   256   12.8 
2026-08-21 05:38 UT   02 56 52.1   +05 03 28     2.369    2.795  104.3   20.5   256   12.8 
2026-08-22 00:00 UT   02 57 18.5   +05 01 27     2.360    2.796  104.9   20.5   256   12.8 
2026-08-23 00:00 UT   02 57 51.9   +04 58 44     2.348    2.797  105.7   20.4   256   12.8 
2026-08-24 00:00 UT   02 58 24.1   +04 55 54     2.337    2.798  106.5   20.3   257   12.8 
2026-08-25 00:00 UT   02 58 55.0   +04 52 56     2.325    2.798  107.4   20.2   257   12.8 
2026-08-26 00:00 UT   02 59 24.8   +04 49 51     2.314    2.799  108.2   20.1   257   12.8 
2026-08-27 00:00 UT   02 59 53.3   +04 46 39     2.302    2.800  109.0   19.9   257   12.8 
2026-08-28 00:00 UT   03 00 20.6   +04 43 20     2.291    2.801  109.9   19.8   258   12.7 
2026-08-29 00:00 UT   03 00 46.7   +04 39 54     2.280    2.801  110.7   19.7   258   12.7 
2026-08-30 00:00 UT   03 01 11.4   +04 36 22     2.269    2.802  111.6   19.6   258   12.7 
2026-08-31 00:00 UT   03 01 34.8   +04 32 42     2.258    2.803  112.4   19.4   258   12.7 
2026-09-01 00:00 UT   03 01 57.0   +04 28 55     2.247    2.804  113.3   19.3   259   12.7 
2026-09-02 00:00 UT   03 02 17.8   +04 25 01     2.236    2.804  114.2   19.2   259   12.7 
2026-09-03 00:00 UT   03 02 37.3   +04 21 01     2.225    2.805  115.0   19.0   259   12.7 
2026-09-04 00:00 UT   03 02 55.4   +04 16 54     2.214    2.806  115.9   18.9   260   12.6 
2026-09-05 00:00 UT   03 03 12.2   +04 12 40     2.204    2.807  116.8   18.7   260   12.6 
2026-09-06 00:00 UT   03 03 27.6   +04 08 20     2.193    2.808  117.7   18.5   260   12.6 
2026-09-07 00:00 UT   03 03 41.6   +04 03 53     2.183    2.808  118.6   18.4   261   12.6 
2026-09-08 00:00 UT   03 03 54.1   +03 59 20     2.173    2.809  119.5   18.2   261   12.6 
2026-09-09 00:00 UT   03 04 05.3   +03 54 40     2.163    2.810  120.4   18.0   261   12.6 
2026-09-10 00:00 UT   03 04 15.1   +03 49 54     2.153    2.811  121.3   17.8   262   12.5 
2026-09-11 00:00 UT   03 04 23.4   +03 45 02     2.143    2.812  122.2   17.6   262   12.5 
2026-09-12 00:00 UT   03 04 30.2   +03 40 05     2.133    2.812  123.1   17.4   262   12.5 
2026-09-13 00:00 UT   03 04 35.6   +03 35 01     2.123    2.813  124.1   17.2   263   12.5 
2026-09-14 00:00 UT   03 04 39.6   +03 29 52     2.114    2.814  125.0   17.0   263   12.5 
2026-09-15 00:00 UT   03 04 42.1   +03 24 38     2.104    2.815  125.9   16.8   263   12.5 
2026-09-16 00:00 UT   03 04 43.2   +03 19 18     2.095    2.816  126.9   16.6   264   12.5 
2026-09-17 00:00 UT   03 04 42.8   +03 13 53     2.086    2.817  127.8   16.4   264   12.4 
2026-09-18 00:00 UT   03 04 40.9   +03 08 23     2.077    2.817  128.8   16.2   265   12.4 
2026-09-19 00:00 UT   03 04 37.6   +03 02 49     2.068    2.818  129.7   15.9   265   12.4 
2026-09-20 00:00 UT   03 04 32.8   +02 57 10     2.060    2.819  130.7   15.7   266   12.4 

    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.