(189) Phthia
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	17 Sep 2025	14.7	2.488 AU	3.275 AU	09h31m	+10°42'	32.6°	12.6°
Opposition	12 Mar 2026	12.6	2.535 AU	1.544 AU	11h25m	-01°05'	175.5°	1.8°

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 Phthia are:

            e (Eccentricity)                : 0.0368750
            a (Semimajor axis)              : 2.4515570
            i (Inclination)                 : 5.17290
            Ω (Longitude of ascending node) : 203.31200
            ω (Argument of perihelion)      : 169.87247
            M (Mean anomaly)                : 77.31625
            Epoch                           : 2025 May 05

            L (Longitude of perihelion)     : 193.22487
            B (Latitude of perihelion)      : 0.90840
            P (Orbital period in years)     : 3.84            
        

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
2025-09-17 00:00 UT   09 31 01.4   +10 42 59     3.275    2.488   32.6   12.6   283   14.7 
2025-09-17 00:53 UT   09 31 05.1   +10 42 41     3.275    2.488   32.6   12.6   283   14.7 
2025-09-18 00:00 UT   09 32 41.4   +10 34 31     3.269    2.489   33.1   12.8   283   14.7 
2025-09-19 00:00 UT   09 34 21.1   +10 26 00     3.262    2.489   33.7   12.9   283   14.7 
2025-09-20 00:00 UT   09 36 00.4   +10 17 28     3.255    2.489   34.2   13.1   283   14.7 
2025-09-21 00:00 UT   09 37 39.5   +10 08 53     3.248    2.490   34.8   13.3   283   14.7 
2025-09-22 00:00 UT   09 39 18.2   +10 00 17     3.241    2.490   35.3   13.5   284   14.7 
2025-09-23 00:00 UT   09 40 56.7   +09 51 39     3.234    2.490   35.8   13.6   284   14.7 
2025-09-24 00:00 UT   09 42 34.8   +09 42 59     3.226    2.491   36.4   13.8   284   14.7 
2025-09-25 00:00 UT   09 44 12.6   +09 34 18     3.219    2.491   36.9   14.0   284   14.7 
2025-09-26 00:00 UT   09 45 50.0   +09 25 36     3.211    2.491   37.5   14.2   284   14.7 
2025-09-27 00:00 UT   09 47 27.2   +09 16 52     3.204    2.492   38.0   14.4   285   14.7 
2025-09-28 00:00 UT   09 49 04.0   +09 08 06     3.196    2.492   38.6   14.5   285   14.7 
2025-09-29 00:00 UT   09 50 40.4   +08 59 19     3.188    2.493   39.1   14.7   285   14.7 
2025-09-30 00:00 UT   09 52 16.6   +08 50 31     3.180    2.493   39.7   14.9   285   14.7 
2025-10-01 00:00 UT   09 53 52.3   +08 41 42     3.172    2.493   40.3   15.0   285   14.7 
2025-10-02 00:00 UT   09 55 27.8   +08 32 52     3.164    2.494   40.8   15.2   285   14.7 
2025-10-03 00:00 UT   09 57 02.9   +08 24 01     3.155    2.494   41.4   15.4   286   14.7 
2025-10-04 00:00 UT   09 58 37.6   +08 15 08     3.147    2.494   41.9   15.6   286   14.7 
2025-10-05 00:00 UT   10 00 12.0   +08 06 15     3.139    2.495   42.5   15.7   286   14.7 
2025-10-06 00:00 UT   10 01 46.0   +07 57 21     3.130    2.495   43.1   15.9   286   14.7 
2025-10-07 00:00 UT   10 03 19.7   +07 48 26     3.121    2.495   43.6   16.0   286   14.7 

    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.