198P/ODAS
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	21 Nov 2025	21.1	2.005 AU	1.040 AU	04h58m	+25°06'	162.5°	8.5°	256°
Nearest approach	3 Dec 2025	21.1	2.007 AU	1.023 AU	04h50m	+25°01'	176.0°	2.0°	224°
Today	26 May 2026	24.3	2.474 AU	2.982 AU	07h53m	+21°39'	51.0°	18.6°	100°

The interactive orbit chart above shows the comet'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.)

Light curve

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations from COBS. The light curve is estimated manually by the author. (18.0 + 5 log[∆] + 10.0 log[r]). An additional green curve is displayed when an increase in apparent brightness is expected due to forward scattering of sunlight, which occurs when a dust-rich comet is located between the Earth and the Sun. (See Marcus 2007)

Charts

The all-sky chart below shows the path of the comet over the same period as the light curve. The comet's current position is marked yellow.

The following chart shows the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Orbital elements

The orbital elements of 198P/ODAS are:

    e (Eccentricity)                : 0.4482470
    q (Perihelion distance)         : 2.0047240
    i (Inclination)                 : 1.33940
    Ω (Longitude of ascending node) : 358.31390
    ω (Argument of perihelion)      : 69.29300
    L (Longitude of perihelion)     : 67.60172
    B (Latitude of perihelion)      : 1.25286
    T (Time of perihelion passage)  : 2461000.64110
    P (Orbital period in years)     : 6.93

    Epoch                           : 2026 May 26
    Reference                       : MPC191611

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.926

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-05-25 00:00 UT   07 50 12.8   +21 48 51     2.957    2.466   52.0   18.9   100   24.3 
2026-05-26 00:00 UT   07 52 05.3   +21 43 33     2.971    2.470   51.5   18.7   100   24.3 
2026-05-26 19:53 UT   07 53 38.3   +21 39 06     2.982    2.474   51.0   18.6   100   24.3 
2026-05-27 00:00 UT   07 53 57.6   +21 38 10     2.984    2.474   51.0   18.5   100   24.3 
2026-05-28 00:00 UT   07 55 49.7   +21 32 44     2.998    2.479   50.4   18.4   100   24.3 
2026-05-29 00:00 UT   07 57 41.7   +21 27 13     3.011    2.483   49.9   18.2   101   24.3 
2026-05-30 00:00 UT   07 59 33.6   +21 21 37     3.024    2.487   49.4   18.0   101   24.4 
2026-05-31 00:00 UT   08 01 25.2   +21 15 58     3.038    2.491   48.9   17.9   101   24.4 
2026-06-01 00:00 UT   08 03 16.8   +21 10 14     3.051    2.495   48.4   17.7   101   24.4 
2026-06-02 00:00 UT   08 05 08.1   +21 04 26     3.064    2.500   47.9   17.5   101   24.4 
2026-06-03 00:00 UT   08 06 59.3   +20 58 34     3.077    2.504   47.3   17.3   101   24.4 
2026-06-04 00:00 UT   08 08 50.4   +20 52 38     3.090    2.508   46.8   17.2   102   24.4 
2026-06-05 00:00 UT   08 10 41.2   +20 46 38     3.103    2.512   46.3   17.0   102   24.5 

    Terminology:
            
    delta:  distance between comet and earth in AU
    radius: distance between comet 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-comet)    
    phase:  phase angle in degrees (angle sun-comet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km      
    

Orbital elements usually provided by the MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database) or 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.