220P/McNaught
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	14 Jun 2026	10.4	1.559 AU	1.507 AU	00h34m	+03°35'	73.5°	38.6°	247°
Today	27 Aug 2026	10.2	1.716 AU	1.142 AU	03h13m	+09°09'	105.6°	34.5°	257°
Nearest approach	12 Oct 2026	10.5	1.924 AU	1.017 AU	03h28m	+04°26'	145.4°	17.1°	277°

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 7.6 + 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 220P/McNaught are:

    e (Eccentricity)                : 0.5003280
    q (Perihelion distance)         : 1.5593020
    i (Inclination)                 : 8.12080
    Ω (Longitude of ascending node) : 150.08400
    ω (Argument of perihelion)      : 180.56160
    L (Longitude of perihelion)     : 150.63997
    B (Latitude of perihelion)      : -0.07933
    T (Time of perihelion passage)  : 2461205.61730
    P (Orbital period in years)     : 5.51

    Epoch                           : 2026 Aug 27
    Reference                       : MPEC 2026-Q97

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.995

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-08-26 00:00 UT   03 11 08.2   +09 15 19     1.150    1.709  104.3   35.0   256   10.2 
2026-08-27 00:00 UT   03 12 25.4   +09 12 33     1.146    1.712  105.0   34.7   257   10.2 
2026-08-27 21:05 UT   03 13 31.4   +09 09 58     1.142    1.716  105.6   34.5   257   10.2 
2026-08-28 00:00 UT   03 13 40.4   +09 09 36     1.141    1.716  105.7   34.5   257   10.2 
2026-08-29 00:00 UT   03 14 53.4   +09 06 28     1.137    1.720  106.3   34.3   257   10.2 
2026-08-30 00:00 UT   03 16 04.2   +09 03 09     1.133    1.724  107.0   34.1   257   10.2 
2026-08-31 00:00 UT   03 17 12.9   +08 59 38     1.129    1.728  107.7   33.8   258   10.2 
2026-09-01 00:00 UT   03 18 19.4   +08 55 56     1.124    1.732  108.4   33.6   258   10.2 
2026-09-02 00:00 UT   03 19 23.7   +08 52 04     1.120    1.736  109.1   33.3   258   10.2 
2026-09-03 00:00 UT   03 20 25.7   +08 48 00     1.116    1.740  109.8   33.0   258   10.2 
2026-09-04 00:00 UT   03 21 25.5   +08 43 46     1.112    1.744  110.6   32.8   259   10.2 
2026-09-05 00:00 UT   03 22 23.0   +08 39 22     1.108    1.748  111.3   32.5   259   10.2 
2026-09-06 00:00 UT   03 23 18.2   +08 34 47     1.104    1.753  112.0   32.2   259   10.3 

    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.