(101) Helena
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	9 May 2025	12.0	2.590 AU	1.606 AU	15h08m	-33°41'	163.5°	6.3°
Opposition	13 May 2025	11.9	2.583 AU	1.595 AU	15h03m	-33°34'	164.4°	6.0°

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 Helena are:

            e (Eccentricity)                : 0.1405820
            a (Semimajor axis)              : 2.5835577
            i (Inclination)                 : 10.19186
            Ω (Longitude of ascending node) : 343.36447
            ω (Argument of perihelion)      : 347.78344
            M (Mean anomaly)                : 276.16155
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 331.33502
            B (Latitude of perihelion)      : -2.14582
            P (Orbital period in years)     : 4.15            
        

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
2025-05-09 00:00 UT   15 08 58.4   -33 41 48     1.606    2.590  163.5    6.3   355   12.0 
2025-05-09 10:44 UT   15 08 28.8   -33 41 14     1.604    2.589  163.7    6.3   357   12.0 
2025-05-10 00:00 UT   15 07 52.2   -33 40 28     1.603    2.588  163.9    6.2   359   12.0 
2025-05-11 00:00 UT   15 06 45.9   -33 38 57     1.600    2.587  164.1    6.1     4   12.0 
2025-05-12 00:00 UT   15 05 39.5   -33 37 13     1.598    2.585  164.3    6.1     8   12.0 
2025-05-13 00:00 UT   15 04 33.0   -33 35 17     1.596    2.584  164.4    6.0    13   11.9 
2025-05-14 00:00 UT   15 03 26.7   -33 33 10     1.594    2.582  164.4    6.0    17   11.9 
2025-05-15 00:00 UT   15 02 20.4   -33 30 51     1.593    2.581  164.3    6.1    22   11.9 
2025-05-16 00:00 UT   15 01 14.4   -33 28 21     1.592    2.579  164.1    6.2    26   11.9 
2025-05-17 00:00 UT   15 00 08.7   -33 25 40     1.591    2.577  163.9    6.3    31   11.9 
2025-05-18 00:00 UT   14 59 03.4   -33 22 48     1.590    2.576  163.5    6.4    35   12.0 
2025-05-19 00:00 UT   14 57 58.6   -33 19 45     1.590    2.574  163.1    6.6    39   12.0 
2025-05-20 00:00 UT   14 56 54.3   -33 16 33     1.589    2.573  162.6    6.7    43   12.0 
2025-05-21 00:00 UT   14 55 50.6   -33 13 10     1.590    2.571  162.1    6.9    46   12.0 
2025-05-22 00:00 UT   14 54 47.7   -33 09 38     1.590    2.570  161.5    7.2    50   12.0 
2025-05-23 00:00 UT   14 53 45.5   -33 05 57     1.590    2.568  160.9    7.4    53   12.0 
2025-05-24 00:00 UT   14 52 44.2   -33 02 07     1.591    2.567  160.2    7.7    56   12.0 
2025-05-25 00:00 UT   14 51 43.8   -32 58 09     1.592    2.565  159.4    8.0    59   12.0 
2025-05-26 00:00 UT   14 50 44.5   -32 54 03     1.594    2.564  158.7    8.3    61   12.0 
2025-05-27 00:00 UT   14 49 46.2   -32 49 49     1.595    2.562  157.9    8.6    64   12.0 
2025-05-28 00:00 UT   14 48 49.1   -32 45 29     1.597    2.561  157.0    8.9    66   12.1 
2025-05-29 00:00 UT   14 47 53.3   -32 41 02     1.599    2.559  156.2    9.2    68   12.1 
2025-05-30 00:00 UT   14 46 58.7   -32 36 29     1.602    2.558  155.3    9.5    70   12.1 
2025-05-31 00:00 UT   14 46 05.5   -32 31 51     1.604    2.556  154.4    9.9    72   12.1 
2025-06-01 00:00 UT   14 45 13.6   -32 27 07     1.607    2.555  153.5   10.2    74   12.1 
2025-06-02 00:00 UT   14 44 23.3   -32 22 20     1.610    2.553  152.6   10.5    75   12.1 
2025-06-03 00:00 UT   14 43 34.4   -32 17 28     1.613    2.552  151.7   10.9    77   12.2 
2025-06-04 00:00 UT   14 42 47.2   -32 12 32     1.617    2.550  150.7   11.2    78   12.2 
2025-06-05 00:00 UT   14 42 01.5   -32 07 34     1.620    2.549  149.8   11.6    80   12.2 
2025-06-06 00:00 UT   14 41 17.4   -32 02 33     1.624    2.547  148.8   11.9    81   12.2 
2025-06-07 00:00 UT   14 40 35.0   -31 57 29     1.629    2.546  147.9   12.2    82   12.2 
2025-06-08 00:00 UT   14 39 54.4   -31 52 24     1.633    2.544  146.9   12.6    83   12.2 

    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.