C/2013 UQ4 (Catalina)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	4 Jul 2014	11.8	1.099 AU	0.387 AU	23h16m	+40°30'	91.7°	67.6°	237°
Nearest approach	9 Jul 2014	11.5	1.102 AU	0.332 AU	20h37m	+59°49'	96.0°	66.6°	199°
Today	3 Jul 2025	34.6	25.367 AU	26.209 AU	09h06m	+15°10'	33.4°	1.3°	109°

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.)

The orbital elements of C/2013 UQ4 (Catalina) are:

            e (Eccentricity)                : 0.9812680
            q (Perihelion distance)         : 1.0987550
            i (Inclination)                 : 145.21210
            Ω (Longitude of ascending node) : 317.80900
            ω (Argument of perihelion)      : 23.74980
            L (Longitude of perihelion)     : 297.94097
            B (Latitude of perihelion)      : 13.28420
            T (Time of perihelion passage)  : 2456842.78700
            P (Orbital period in years)     : 449.24

            Epoch                           : 2020 Sep 26
            Reference                       : MPC102951

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

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. The light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (13.50 + 5 log[∆] + 10.00 log[r]).

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-07-03 00:00 UT   09 06 22.7   +15 10 57    26.206   25.366   33.6    1.3   109   34.6 
2025-07-03 04:46 UT   09 06 24.1   +15 10 50    26.209   25.367   33.4    1.3   109   34.6 
2025-07-04 00:00 UT   09 06 29.7   +15 10 23    26.220   25.370   32.6    1.2   109   34.6 
2025-07-05 00:00 UT   09 06 36.7   +15 09 50    26.233   25.374   31.7    1.2   109   34.6 
2025-07-06 00:00 UT   09 06 43.8   +15 09 16    26.246   25.379   30.8    1.2   109   34.6 
2025-07-07 00:00 UT   09 06 50.9   +15 08 41    26.258   25.383   29.9    1.1   109   34.6 
2025-07-08 00:00 UT   09 06 58.1   +15 08 07    26.271   25.387   29.0    1.1   109   34.6 
2025-07-09 00:00 UT   09 07 05.4   +15 07 32    26.283   25.391   28.0    1.1   109   34.6 
2025-07-10 00:00 UT   09 07 12.8   +15 06 56    26.295   25.395   27.1    1.0   109   34.6 
2025-07-11 00:00 UT   09 07 20.1   +15 06 21    26.307   25.399   26.2    1.0   110   34.6 
2025-07-12 00:00 UT   09 07 27.6   +15 05 45    26.318   25.403   25.3    1.0   110   34.7 
2025-07-13 00:00 UT   09 07 35.1   +15 05 08    26.329   25.407   24.4    0.9   110   34.7 

    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.