(101) Helena
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	25 Sep 2023	14.3	2.867 AU	3.433 AU	09h10m	+22°41'	48.4°	15.2°
Opposition	13 Feb 2024	12.5	2.943 AU	1.958 AU	09h52m	+18°22'	174.9°	1.7°

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)                : 0.1411431
            a (Semimajor axis)              : 2.5825225
            i (Inclination)                 : 10.19496
            Ω (Longitude of ascending node) : 343.37109
            ω (Argument of perihelion)      : 347.94344
            M (Mean anomaly)                : 86.00708
            Epoch                           : 2023 Feb 25

            L (Longitude of perihelion)     : 331.49945
            B (Latitude of perihelion)      : -2.11876
            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
2023-09-25 00:00 UT   09 10 09.8   +22 41 08     3.433    2.867   48.4   15.2   293   14.3 
2023-09-25 12:56 UT   09 10 54.7   +22 37 54     3.428    2.868   48.8   15.3   293   14.3 
2023-09-26 00:00 UT   09 11 32.9   +22 35 09     3.423    2.868   49.1   15.3   293   14.3 
2023-09-27 00:00 UT   09 12 55.5   +22 29 10     3.413    2.869   49.7   15.5   293   14.3 
2023-09-28 00:00 UT   09 14 17.5   +22 23 11     3.404    2.870   50.4   15.6   293   14.3 
2023-09-29 00:00 UT   09 15 39.0   +22 17 13     3.394    2.871   51.0   15.7   293   14.3 
2023-09-30 00:00 UT   09 17 00.0   +22 11 15     3.384    2.872   51.6   15.9   292   14.3 
2023-10-01 00:00 UT   09 18 20.5   +22 05 17     3.373    2.872   52.3   16.0   292   14.3 
2023-10-02 00:00 UT   09 19 40.5   +21 59 20     3.363    2.873   52.9   16.1   292   14.3 
2023-10-03 00:00 UT   09 20 59.9   +21 53 24     3.353    2.874   53.6   16.3   292   14.3 
2023-10-04 00:00 UT   09 22 18.8   +21 47 28     3.342    2.875   54.3   16.4   292   14.3 
2023-10-05 00:00 UT   09 23 37.1   +21 41 34     3.332    2.876   54.9   16.5   292   14.3 
2023-10-06 00:00 UT   09 24 54.9   +21 35 40     3.321    2.876   55.6   16.7   292   14.3 
2023-10-07 00:00 UT   09 26 12.1   +21 29 47     3.310    2.877   56.2   16.8   292   14.3 
2023-10-08 00:00 UT   09 27 28.8   +21 23 55     3.299    2.878   56.9   16.9   292   14.3 
2023-10-09 00:00 UT   09 28 44.8   +21 18 05     3.288    2.879   57.6   17.0   292   14.3 
2023-10-10 00:00 UT   09 30 00.3   +21 12 15     3.277    2.880   58.2   17.2   292   14.3 
2023-10-11 00:00 UT   09 31 15.2   +21 06 27     3.266    2.880   58.9   17.3   292   14.2 
2023-10-12 00:00 UT   09 32 29.5   +21 00 40     3.255    2.881   59.6   17.4   292   14.2 
2023-10-13 00:00 UT   09 33 43.2   +20 54 55     3.243    2.882   60.3   17.5   292   14.2 
2023-10-14 00:00 UT   09 34 56.2   +20 49 12     3.232    2.883   61.0   17.6   292   14.2 
2023-10-15 00:00 UT   09 36 08.7   +20 43 30     3.220    2.884   61.6   17.7   292   14.2 
2023-10-16 00:00 UT   09 37 20.4   +20 37 50     3.209    2.884   62.3   17.8   292   14.2 
2023-10-17 00:00 UT   09 38 31.6   +20 32 11     3.197    2.885   63.0   17.9   292   14.2 
2023-10-18 00:00 UT   09 39 42.1   +20 26 35     3.185    2.886   63.7   18.0   292   14.2 
2023-10-19 00:00 UT   09 40 51.9   +20 21 01     3.173    2.887   64.4   18.1   292   14.2 
2023-10-20 00:00 UT   09 42 01.1   +20 15 29     3.161    2.887   65.1   18.2   292   14.2 
2023-10-21 00:00 UT   09 43 09.5   +20 09 59     3.149    2.888   65.8   18.3   292   14.2 
2023-10-22 00:00 UT   09 44 17.3   +20 04 31     3.137    2.889   66.5   18.4   292   14.2 

    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.