C/2019 Q1 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	22 Jul 2020	18.7	4.995 AU	4.438 AU	23h20m	+20°29'	117.9°	10.4°	232°
Nearest approach	3 Sep 2020	18.5	5.006 AU	4.083 AU	22h19m	+17°56'	153.5°	5.2°	163°
Today	14 Sep 2026	26.4	15.425 AU	15.907 AU	15h21m	-13°01'	59.7°	3.2°	102°

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. 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. (8.5 + 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/2019 Q1 (Lemmon) are:

    e (Eccentricity)                : 1.0024540
    q (Perihelion distance)         : 4.9953270
    i (Inclination)                 : 155.69870
    Ω (Longitude of ascending node) : 42.48310
    ω (Argument of perihelion)      : 56.20940
    L (Longitude of perihelion)     : 348.77161
    B (Latitude of perihelion)      : 19.99979
    T (Time of perihelion passage)  : 2459053.18210

    Epoch                           : 2026 Sep 14
    Reference                       : MPC194163

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-09-13 00:00 UT   15 21 15.8   -12 59 56    15.868   15.415   61.6    3.3   102   26.4 
2026-09-14 00:00 UT   15 21 20.0   -13 00 50    15.888   15.420   60.6    3.3   102   26.4 
2026-09-14 23:16 UT   15 21 24.2   -13 01 42    15.907   15.425   59.7    3.2   102   26.4 
2026-09-15 00:00 UT   15 21 24.3   -13 01 44    15.908   15.425   59.7    3.2   102   26.4 
2026-09-16 00:00 UT   15 21 29.0   -13 02 38    15.927   15.430   58.7    3.2   102   26.4 
2026-09-17 00:00 UT   15 21 33.8   -13 03 33    15.947   15.435   57.8    3.2   101   26.4 
2026-09-18 00:00 UT   15 21 38.8   -13 04 29    15.967   15.440   56.9    3.1   101   26.4 
2026-09-19 00:00 UT   15 21 44.0   -13 05 25    15.986   15.446   55.9    3.1   101   26.4 
2026-09-20 00:00 UT   15 21 49.4   -13 06 21    16.005   15.451   55.0    3.1   101   26.4 
2026-09-21 00:00 UT   15 21 55.0   -13 07 18    16.024   15.456   54.0    3.0   101   26.4 
2026-09-22 00:00 UT   15 22 00.8   -13 08 16    16.043   15.461   53.1    3.0   101   26.4 
2026-09-23 00:00 UT   15 22 06.8   -13 09 13    16.061   15.466   52.1    2.9   101   26.4 
2026-09-24 00:00 UT   15 22 13.0   -13 10 12    16.080   15.471   51.2    2.9   101   26.4 

    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.