(221) Eos
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	4 May 2025	12.9	2.832 AU	2.371 AU	19h46m	-11°42'	106.8°	19.9°
Opposition	13 Jul 2025	11.5	2.777 AU	1.768 AU	19h28m	-13°04'	171.3°	3.2°

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)                : 0.1012016
            a (Semimajor axis)              : 3.0129160
            i (Inclination)                 : 10.88931
            Ω (Longitude of ascending node) : 141.71231
            ω (Argument of perihelion)      : 192.48735
            M (Mean anomaly)                : 311.25730
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 153.98168
            B (Latitude of perihelion)      : -2.34103
            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. 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
2025-05-04 00:00 UT   19 46 26.6   -11 42 13     2.371    2.832  106.8   19.9   257   12.9 
2025-05-04 06:52 UT   19 46 35.0   -11 41 33     2.367    2.832  107.1   19.9   257   12.9 
2025-05-05 00:00 UT   19 46 55.6   -11 39 53     2.357    2.831  107.6   19.8   257   12.9 
2025-05-06 00:00 UT   19 47 23.5   -11 37 36     2.344    2.830  108.5   19.8   256   12.8 
2025-05-07 00:00 UT   19 47 50.1   -11 35 24     2.331    2.829  109.3   19.7   256   12.8 
2025-05-08 00:00 UT   19 48 15.5   -11 33 15     2.317    2.829  110.2   19.6   256   12.8 
2025-05-09 00:00 UT   19 48 39.6   -11 31 10     2.304    2.828  111.0   19.5   256   12.8 
2025-05-10 00:00 UT   19 49 02.5   -11 29 09     2.291    2.827  111.9   19.4   256   12.8 
2025-05-11 00:00 UT   19 49 24.1   -11 27 13     2.278    2.826  112.7   19.2   255   12.8 
2025-05-12 00:00 UT   19 49 44.5   -11 25 21     2.265    2.825  113.6   19.1   255   12.7 
2025-05-13 00:00 UT   19 50 03.5   -11 23 33     2.252    2.824  114.5   19.0   255   12.7 
2025-05-14 00:00 UT   19 50 21.2   -11 21 51     2.239    2.823  115.3   18.9   255   12.7 
2025-05-15 00:00 UT   19 50 37.7   -11 20 13     2.227    2.823  116.2   18.7   254   12.7 
2025-05-16 00:00 UT   19 50 52.8   -11 18 40     2.214    2.822  117.1   18.6   254   12.7 
2025-05-17 00:00 UT   19 51 06.6   -11 17 12     2.202    2.821  118.0   18.5   254   12.7 
2025-05-18 00:00 UT   19 51 19.0   -11 15 49     2.189    2.820  118.9   18.3   254   12.6 
2025-05-19 00:00 UT   19 51 30.1   -11 14 32     2.177    2.819  119.8   18.2   254   12.6 
2025-05-20 00:00 UT   19 51 39.8   -11 13 20     2.165    2.818  120.7   18.0   253   12.6 
2025-05-21 00:00 UT   19 51 48.1   -11 12 14     2.153    2.818  121.6   17.8   253   12.6 
2025-05-22 00:00 UT   19 51 55.1   -11 11 14     2.141    2.817  122.5   17.6   253   12.6 
2025-05-23 00:00 UT   19 52 00.6   -11 10 20     2.129    2.816  123.4   17.5   253   12.5 
2025-05-24 00:00 UT   19 52 04.7   -11 09 31     2.117    2.815  124.3   17.3   252   12.5 
2025-05-25 00:00 UT   19 52 07.5   -11 08 49     2.106    2.814  125.2   17.1   252   12.5 
2025-05-26 00:00 UT   19 52 08.8   -11 08 14     2.094    2.814  126.2   16.9   252   12.5 
2025-05-27 00:00 UT   19 52 08.7   -11 07 44     2.083    2.813  127.1   16.7   252   12.5 
2025-05-28 00:00 UT   19 52 07.2   -11 07 22     2.072    2.812  128.1   16.5   251   12.5 
2025-05-29 00:00 UT   19 52 04.3   -11 07 06     2.061    2.811  129.0   16.3   251   12.4 
2025-05-30 00:00 UT   19 51 59.9   -11 06 57     2.050    2.810  130.0   16.1   251   12.4 
2025-05-31 00:00 UT   19 51 54.2   -11 06 55     2.039    2.810  130.9   15.8   251   12.4 
2025-06-01 00:00 UT   19 51 47.0   -11 06 59     2.029    2.809  131.9   15.6   250   12.4 
2025-06-02 00:00 UT   19 51 38.4   -11 07 11     2.018    2.808  132.8   15.4   250   12.4 
2025-06-03 00:00 UT   19 51 28.5   -11 07 30     2.008    2.807  133.8   15.1   250   12.3 

    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.