C/2019 D1 (Flewelling)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	7 May 2019	14.7	1.592 AU	1.646 AU	22h03m	+21°04'	68.9°	36.3°	259°
Nearest approach	10 Sep 2019	17.4	2.290 AU	1.567 AU	01h13m	+44°07'	124.1°	21.3°	217°
Today	23 Sep 2026	40.0	19.493 AU	19.439 AU	05h53m	+02°55'	91.6°	2.9°	270°

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 9.9 + 5 log[∆] + 18.4 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 C/2019 D1 (Flewelling) are:

    e (Eccentricity)                : 0.9881120
    q (Perihelion distance)         : 1.5915730
    i (Inclination)                 : 34.05000
    Ω (Longitude of ascending node) : 231.71940
    ω (Argument of perihelion)      : 70.64420
    L (Longitude of perihelion)     : 298.74340
    B (Latitude of perihelion)      : 31.88857
    T (Time of perihelion passage)  : 2458611.30140
    P (Orbital period in years)     : 1549.09

    Epoch                           : 2026 May 29
    Reference                       : MPC194160

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-09-22 00:00 UT   05 53 50.3   +02 56 55    19.455   19.486   90.3    3.0   269   40.0 
2026-09-23 00:00 UT   05 53 50.8   +02 55 44    19.444   19.491   91.2    3.0   270   40.0 
2026-09-23 10:07 UT   05 53 51.0   +02 55 14    19.439   19.493   91.6    2.9   270   40.0 
2026-09-24 00:00 UT   05 53 51.1   +02 54 33    19.433   19.496   92.1    2.9   270   40.0 
2026-09-25 00:00 UT   05 53 51.2   +02 53 22    19.422   19.501   93.0    2.9   270   40.0 
2026-09-26 00:00 UT   05 53 51.1   +02 52 11    19.411   19.506   93.9    2.9   271   40.0 
2026-09-27 00:00 UT   05 53 50.7   +02 50 60    19.400   19.511   94.9    2.9   271   40.0 
2026-09-28 00:00 UT   05 53 50.2   +02 49 48    19.390   19.516   95.8    2.9   272   40.0 
2026-09-29 00:00 UT   05 53 49.4   +02 48 37    19.379   19.522   96.7    2.9   272   40.0 
2026-09-30 00:00 UT   05 53 48.5   +02 47 26    19.368   19.527   97.6    2.9   272   40.0 
2026-10-01 00:00 UT   05 53 47.3   +02 46 15    19.357   19.532   98.5    2.9   273   40.0 
2026-10-02 00:00 UT   05 53 46.0   +02 45 04    19.347   19.537   99.5    2.9   273   40.0 
2026-10-03 00:00 UT   05 53 44.4   +02 43 53    19.336   19.542  100.4    2.9   273   40.0 

    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.