(385) Ilmatar
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Opposition	27 Jul 2025	12.2	3.051 AU	2.054 AU	20h44m	-31°45'	166.8°	4.4°
Today	16 Sep 2025	13.0	3.098 AU	2.416 AU	20h08m	-29°33'	124.4°	15.5°

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 Ilmatar are:

            e (Eccentricity)                : 0.1269207
            a (Semimajor axis)              : 2.8476064
            i (Inclination)                 : 13.58186
            Ω (Longitude of ascending node) : 344.83445
            ω (Argument of perihelion)      : 189.10318
            M (Mean anomaly)                : 142.13283
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 353.68715
            B (Latitude of perihelion)      : -2.12925
            P (Orbital period in years)     : 4.81            
        

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
2025-09-16 00:00 UT   20 08 43.5   -29 33 04     2.416    3.098  124.4   15.5    71   13.0 
2025-09-16 20:46 UT   20 08 36.7   -29 28 40     2.427    3.099  123.6   15.7    72   13.0 
2025-09-17 00:00 UT   20 08 35.7   -29 27 59     2.429    3.099  123.5   15.7    72   13.1 
2025-09-18 00:00 UT   20 08 29.4   -29 22 50     2.441    3.100  122.5   15.9    72   13.1 
2025-09-19 00:00 UT   20 08 24.6   -29 17 38     2.454    3.101  121.6   16.0    72   13.1 
2025-09-20 00:00 UT   20 08 21.3   -29 12 23     2.467    3.101  120.6   16.2    72   13.1 
2025-09-21 00:00 UT   20 08 19.6   -29 07 05     2.480    3.102  119.7   16.3    73   13.1 
2025-09-22 00:00 UT   20 08 19.3   -29 01 44     2.493    3.103  118.8   16.5    73   13.1 
2025-09-23 00:00 UT   20 08 20.6   -28 56 21     2.506    3.104  117.8   16.6    73   13.2 
2025-09-24 00:00 UT   20 08 23.4   -28 50 55     2.519    3.105  116.9   16.8    73   13.2 
2025-09-25 00:00 UT   20 08 27.6   -28 45 26     2.533    3.106  116.0   16.9    74   13.2 
2025-09-26 00:00 UT   20 08 33.3   -28 39 55     2.546    3.106  115.0   17.0    74   13.2 
2025-09-27 00:00 UT   20 08 40.5   -28 34 22     2.560    3.107  114.1   17.1    74   13.2 
2025-09-28 00:00 UT   20 08 49.1   -28 28 46     2.573    3.108  113.2   17.2    74   13.2 
2025-09-29 00:00 UT   20 08 59.1   -28 23 08     2.587    3.109  112.3   17.3    74   13.3 
2025-09-30 00:00 UT   20 09 10.5   -28 17 28     2.601    3.110  111.4   17.4    74   13.3 
2025-10-01 00:00 UT   20 09 23.3   -28 11 46     2.615    3.110  110.5   17.5    75   13.3 
2025-10-02 00:00 UT   20 09 37.5   -28 06 02     2.629    3.111  109.6   17.6    75   13.3 
2025-10-03 00:00 UT   20 09 53.0   -28 00 16     2.643    3.112  108.7   17.7    75   13.3 
2025-10-04 00:00 UT   20 10 09.9   -27 54 29     2.657    3.113  107.8   17.8    75   13.3 
2025-10-05 00:00 UT   20 10 28.0   -27 48 39     2.672    3.114  106.9   17.9    75   13.3 
2025-10-06 00:00 UT   20 10 47.5   -27 42 48     2.686    3.115  106.1   18.0    75   13.4 
2025-10-07 00:00 UT   20 11 08.3   -27 36 54     2.701    3.115  105.2   18.0    75   13.4 
2025-10-08 00:00 UT   20 11 30.3   -27 30 60     2.715    3.116  104.3   18.1    76   13.4 
2025-10-09 00:00 UT   20 11 53.6   -27 25 03     2.730    3.117  103.4   18.2    76   13.4 
2025-10-10 00:00 UT   20 12 18.0   -27 19 05     2.744    3.118  102.6   18.2    76   13.4 
2025-10-11 00:00 UT   20 12 43.7   -27 13 05     2.759    3.118  101.7   18.3    76   13.4 
2025-10-12 00:00 UT   20 13 10.6   -27 07 04     2.773    3.119  100.8   18.3    76   13.4 
2025-10-13 00:00 UT   20 13 38.7   -27 01 01     2.788    3.120  100.0   18.4    76   13.5 
2025-10-14 00:00 UT   20 14 07.9   -26 54 57     2.803    3.121   99.1   18.4    76   13.5 
2025-10-15 00:00 UT   20 14 38.3   -26 48 51     2.818    3.122   98.3   18.4    76   13.5 
2025-10-16 00:00 UT   20 15 09.8   -26 42 43     2.833    3.122   97.4   18.5    76   13.5 

    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.