(124) Alkeste
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	18 Sep 2025	12.9	2.465 AU	2.245 AU	17h40m	-20°10'	90.3°	24.1°
Opposition	14 Oct 2026	11.6	2.758 AU	1.761 AU	01h21m	+07°25'	178.7°	0.5°

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 Alkeste are:

            e (Eccentricity)                : 0.0784099
            a (Semimajor axis)              : 2.6298480
            i (Inclination)                 : 2.96348
            Ω (Longitude of ascending node) : 187.90218
            ω (Argument of perihelion)      : 61.59312
            M (Mean anomaly)                : 49.17832
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 249.46320
            B (Latitude of perihelion)      : 2.60639
            P (Orbital period in years)     : 4.26            
        

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
2025-09-18 00:00 UT   17 40 04.5   -20 10 11     2.245    2.465   90.3   24.1    92   12.9 
2025-09-18 18:08 UT   17 40 57.3   -20 11 32     2.255    2.466   89.8   24.0    92   12.9 
2025-09-19 00:00 UT   17 41 14.5   -20 11 58     2.258    2.466   89.6   24.0    92   12.9 
2025-09-20 00:00 UT   17 42 25.5   -20 13 43     2.271    2.466   88.9   24.0    92   12.9 
2025-09-21 00:00 UT   17 43 37.5   -20 15 26     2.284    2.467   88.2   24.0    92   12.9 
2025-09-22 00:00 UT   17 44 50.4   -20 17 07     2.297    2.468   87.5   24.0    91   13.0 
2025-09-23 00:00 UT   17 46 04.3   -20 18 45     2.311    2.468   86.9   24.0    91   13.0 
2025-09-24 00:00 UT   17 47 19.1   -20 20 21     2.324    2.469   86.2   23.9    91   13.0 
2025-09-25 00:00 UT   17 48 34.9   -20 21 54     2.337    2.469   85.5   23.9    91   13.0 
2025-09-26 00:00 UT   17 49 51.5   -20 23 25     2.350    2.470   84.8   23.8    91   13.0 
2025-09-27 00:00 UT   17 51 09.0   -20 24 52     2.363    2.470   84.1   23.8    91   13.0 
2025-09-28 00:00 UT   17 52 27.4   -20 26 17     2.375    2.471   83.5   23.8    90   13.0 
2025-09-29 00:00 UT   17 53 46.7   -20 27 38     2.388    2.471   82.8   23.7    90   13.0 
2025-09-30 00:00 UT   17 55 06.8   -20 28 57     2.401    2.472   82.1   23.7    90   13.1 
2025-10-01 00:00 UT   17 56 27.7   -20 30 12     2.414    2.473   81.5   23.6    90   13.1 
2025-10-02 00:00 UT   17 57 49.4   -20 31 25     2.427    2.473   80.8   23.5    90   13.1 
2025-10-03 00:00 UT   17 59 11.9   -20 32 34     2.440    2.474   80.1   23.5    90   13.1 
2025-10-04 00:00 UT   18 00 35.2   -20 33 39     2.453    2.474   79.5   23.4    89   13.1 
2025-10-05 00:00 UT   18 01 59.2   -20 34 42     2.466    2.475   78.8   23.4    89   13.1 
2025-10-06 00:00 UT   18 03 24.0   -20 35 40     2.479    2.475   78.2   23.3    89   13.1 
2025-10-07 00:00 UT   18 04 49.5   -20 36 35     2.492    2.476   77.5   23.2    89   13.1 
2025-10-08 00:00 UT   18 06 15.7   -20 37 27     2.505    2.477   76.9   23.1    89   13.1 
2025-10-09 00:00 UT   18 07 42.6   -20 38 15     2.517    2.477   76.2   23.1    89   13.1 
2025-10-10 00:00 UT   18 09 10.2   -20 38 59     2.530    2.478   75.6   23.0    88   13.1 
2025-10-11 00:00 UT   18 10 38.5   -20 39 39     2.543    2.478   74.9   22.9    88   13.2 
2025-10-12 00:00 UT   18 12 07.4   -20 40 16     2.556    2.479   74.3   22.8    88   13.2 
2025-10-13 00:00 UT   18 13 37.1   -20 40 48     2.568    2.480   73.7   22.7    88   13.2 
2025-10-14 00:00 UT   18 15 07.3   -20 41 17     2.581    2.480   73.0   22.6    88   13.2 

    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.