(42) Isis
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	23 Dec 2025	11.3	2.732 AU	1.750 AU	06h23m	+25°34'	175.1°	1.8°
Opposition	25 Dec 2025	11.3	2.736 AU	1.753 AU	06h20m	+25°42'	177.4°	0.9°

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 Isis are:

            e (Eccentricity)                : 0.2219265
            a (Semimajor axis)              : 2.4437922
            i (Inclination)                 : 8.51002
            Ω (Longitude of ascending node) : 84.16707
            ω (Argument of perihelion)      : 237.41146
            M (Mean anomaly)                : 103.03901
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 141.29001
            B (Latitude of perihelion)      : -7.16251
            P (Orbital period in years)     : 3.82            
        

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
2025-12-23 00:00 UT   06 23 47.7   +25 34 18     1.750    2.732  175.1    1.8   245   11.3 
2025-12-23 20:17 UT   06 22 49.2   +25 37 10     1.751    2.733  176.0    1.4   237   11.3 
2025-12-24 00:00 UT   06 22 38.5   +25 37 41     1.751    2.734  176.2    1.4   235   11.3 
2025-12-25 00:00 UT   06 21 29.2   +25 41 01     1.753    2.735  177.1    1.1   219   11.3 
2025-12-26 00:00 UT   06 20 19.9   +25 44 18     1.754    2.737  177.6    0.9   194   11.2 
2025-12-27 00:00 UT   06 19 10.6   +25 47 30     1.756    2.739  177.4    0.9   164   11.3 
2025-12-28 00:00 UT   06 18 01.5   +25 50 38     1.758    2.741  176.8    1.2   142   11.3 
2025-12-29 00:00 UT   06 16 52.6   +25 53 43     1.761    2.743  175.8    1.5   129   11.3 
2025-12-30 00:00 UT   06 15 44.0   +25 56 43     1.764    2.745  174.7    1.9   120   11.4 
2025-12-31 00:00 UT   06 14 35.9   +25 59 39     1.767    2.746  173.5    2.3   115   11.4 
2026-01-01 00:00 UT   06 13 28.1   +26 02 30     1.770    2.748  172.4    2.7   111   11.4 
2026-01-02 00:00 UT   06 12 21.0   +26 05 18     1.774    2.750  171.1    3.2   109   11.5 
2026-01-03 00:00 UT   06 11 14.4   +26 08 01     1.778    2.752  169.9    3.6   107   11.5 
2026-01-04 00:00 UT   06 10 08.5   +26 10 40     1.783    2.754  168.7    4.0   105   11.5 
2026-01-05 00:00 UT   06 09 03.4   +26 13 14     1.787    2.755  167.4    4.5   104   11.6 
2026-01-06 00:00 UT   06 07 59.0   +26 15 44     1.792    2.757  166.2    4.9   102   11.6 
2026-01-07 00:00 UT   06 06 55.6   +26 18 09     1.797    2.759  165.0    5.3   101   11.6 
2026-01-08 00:00 UT   06 05 53.1   +26 20 31     1.803    2.761  163.7    5.7   101   11.6 
2026-01-09 00:00 UT   06 04 51.7   +26 22 48     1.809    2.762  162.5    6.1   100   11.7 
2026-01-10 00:00 UT   06 03 51.3   +26 25 01     1.815    2.764  161.3    6.6    99   11.7 
2026-01-11 00:00 UT   06 02 52.1   +26 27 09     1.821    2.766  160.0    7.0    99   11.7 
2026-01-12 00:00 UT   06 01 54.0   +26 29 14     1.828    2.768  158.8    7.4    98   11.8 
2026-01-13 00:00 UT   06 00 57.3   +26 31 15     1.835    2.769  157.6    7.8    98   11.8 
2026-01-14 00:00 UT   06 00 01.8   +26 33 11     1.842    2.771  156.4    8.2    97   11.8 
2026-01-15 00:00 UT   05 59 07.7   +26 35 04     1.849    2.773  155.1    8.6    97   11.8 
2026-01-16 00:00 UT   05 58 15.1   +26 36 53     1.857    2.774  153.9    9.0    96   11.9 
2026-01-17 00:00 UT   05 57 23.9   +26 38 39     1.865    2.776  152.7    9.3    96   11.9 
2026-01-18 00:00 UT   05 56 34.2   +26 40 21     1.873    2.778  151.5    9.7    96   11.9 
2026-01-19 00:00 UT   05 55 46.0   +26 41 59     1.881    2.780  150.3   10.1    95   11.9 
2026-01-20 00:00 UT   05 54 59.5   +26 43 34     1.890    2.781  149.2   10.5    95   12.0 
2026-01-21 00:00 UT   05 54 14.5   +26 45 06     1.899    2.783  148.0   10.8    95   12.0 
2026-01-22 00:00 UT   05 53 31.3   +26 46 35     1.908    2.785  146.8   11.2    94   12.0 

    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.