C/2026 C1 (Tsuchinshan)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	19 Apr 2026	18.5	9.484 AU	8.587 AU	12h23m	+07°34'	151.9°	2.9°	131°
Perihelion	6 Nov 2028	4.7	1.152 AU	0.999 AU	19h07m	-82°46'	70.8°	54.3°	113°
Nearest approach	11 Nov 2028	4.7	1.155 AU	0.988 AU	20h40m	-74°46'	71.4°	54.4°	92°

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 4.1 + 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 C/2026 C1 (Tsuchinshan) are:

    e (Eccentricity)                : 0.9999120
    q (Perihelion distance)         : 1.1524420
    i (Inclination)                 : 99.59660
    Ω (Longitude of ascending node) : 3.61880
    ω (Argument of perihelion)      : 310.71950
    L (Longitude of perihelion)     : 14.58042
    B (Latitude of perihelion)      : -48.35756
    T (Time of perihelion passage)  : 2462082.49250

    Epoch                           : 2026 Apr 18
    Reference                       : MPEC 2026-G41

    Classification(s):              : Nearly isotropic; New (a > 10000 AU)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-04-18 00:00 UT   12 23 47.7   +07 32 35     8.587    9.494  153.3    2.7   133   18.5 
2026-04-19 00:00 UT   12 23 21.1   +07 33 49     8.587    9.487  152.3    2.8   132   18.5 
2026-04-19 07:55 UT   12 23 12.3   +07 34 14     8.587    9.484  151.9    2.9   131   18.5 
2026-04-20 00:00 UT   12 22 54.6   +07 35 02     8.587    9.479  151.3    2.9   131   18.5 
2026-04-21 00:00 UT   12 22 28.3   +07 36 12     8.587    9.472  150.2    3.0   130   18.5 
2026-04-22 00:00 UT   12 22 02.2   +07 37 19     8.588    9.465  149.2    3.1   129   18.5 
2026-04-23 00:00 UT   12 21 36.3   +07 38 25     8.588    9.457  148.2    3.2   129   18.5 
2026-04-24 00:00 UT   12 21 10.6   +07 39 27     8.589    9.450  147.2    3.3   128   18.5 
2026-04-25 00:00 UT   12 20 45.1   +07 40 28     8.591    9.442  146.1    3.4   127   18.5 
2026-04-26 00:00 UT   12 20 19.8   +07 41 26     8.592    9.435  145.1    3.5   127   18.5 
2026-04-27 00:00 UT   12 19 54.8   +07 42 21     8.594    9.427  144.1    3.6   126   18.5 
2026-04-28 00:00 UT   12 19 29.9   +07 43 14     8.596    9.420  143.1    3.7   126   18.5 
2026-04-29 00:00 UT   12 19 05.3   +07 44 04     8.599    9.413  142.0    3.8   125   18.5 

    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.