174P/Echeclus
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	19 Apr 2015	12.7	5.867 AU	6.533 AU	22h58m	-05°21'	45.0°	7.0°	249°
Nearest approach	9 Sep 2015	12.1	5.906 AU	4.900 AU	23h19m	-03°53'	177.0°	0.5°	239°
Today	14 Oct 2025	23.7	13.746 AU	13.997 AU	08h35m	+15°16'	73.4°	4.0°	284°

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. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently -10.9 + 5 log[∆] + 25.4 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 174P/Echeclus are:

    e (Eccentricity)                : 0.4547310
    q (Perihelion distance)         : 5.8665610
    i (Inclination)                 : 4.34070
    Ω (Longitude of ascending node) : 173.34250
    ω (Argument of perihelion)      : 163.42610
    L (Longitude of perihelion)     : 156.81354
    B (Latitude of perihelion)      : 1.23710
    T (Time of perihelion passage)  : 2457131.87730
    P (Orbital period in years)     : 35.29

    Epoch                           : 2025 Jul 29
    Reference                       : MPC 92985

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); Halley type (P < 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-10-14 00:00 UT   08 35 27.8   +15 16 43    14.000   13.745   73.3    4.0   283   23.7 
2025-10-14 03:59 UT   08 35 29.2   +15 16 36    13.997   13.746   73.4    4.0   284   23.7 
2025-10-15 00:00 UT   08 35 35.7   +15 16 02    13.985   13.747   74.2    4.0   284   23.7 
2025-10-16 00:00 UT   08 35 43.2   +15 15 22    13.970   13.748   75.2    4.0   284   23.7 
2025-10-17 00:00 UT   08 35 50.5   +15 14 43    13.955   13.750   76.1    4.0   284   23.7 
2025-10-18 00:00 UT   08 35 57.5   +15 14 05    13.940   13.751   77.1    4.1   284   23.7 
2025-10-19 00:00 UT   08 36 04.2   +15 13 28    13.924   13.753   78.0    4.1   284   23.7 
2025-10-20 00:00 UT   08 36 10.6   +15 12 52    13.909   13.754   79.0    4.1   284   23.7 
2025-10-21 00:00 UT   08 36 16.8   +15 12 17    13.894   13.756   80.0    4.1   284   23.7 
2025-10-22 00:00 UT   08 36 22.7   +15 11 43    13.879   13.757   80.9    4.1   284   23.7 
2025-10-23 00:00 UT   08 36 28.3   +15 11 10    13.863   13.759   81.9    4.1   284   23.7 
2025-10-24 00:00 UT   08 36 33.6   +15 10 37    13.848   13.760   82.9    4.1   284   23.7 

    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.