C/2019 Q1 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	22 Jul 2020	18.7	4.998 AU	4.441 AU	23h20m	+20°28'	117.9°	10.3°	232°
Nearest approach	3 Sep 2020	18.6	5.009 AU	4.086 AU	22h19m	+17°55'	153.5°	5.2°	163°
Today	1 May 2026	25.9	14.723 AU	13.762 AU	15h46m	-13°09'	161.9°	1.2°	262°

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)                : 1.0025250
    q (Perihelion distance)         : 4.9979470
    i (Inclination)                 : 155.70640
    Ω (Longitude of ascending node) : 42.47830
    ω (Argument of perihelion)      : 56.22900
    L (Longitude of perihelion)     : 348.74492
    B (Latitude of perihelion)      : 19.99836
    T (Time of perihelion passage)  : 2459053.12110

    Epoch                           : 2026 Apr 30
    Reference                       : MPEC 2026-E44

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-04-30 00:00 UT   15 47 24.4   -13 10 49    13.762   14.716  160.6    1.3   263   25.9 
2026-05-01 00:00 UT   15 47 04.5   -13 09 57    13.762   14.722  161.6    1.2   262   25.9 
2026-05-01 06:39 UT   15 46 59.0   -13 09 43    13.762   14.723  161.9    1.2   262   25.9 
2026-05-02 00:00 UT   15 46 44.5   -13 09 05    13.762   14.727  162.6    1.2   261   25.9 
2026-05-03 00:00 UT   15 46 24.5   -13 08 14    13.762   14.732  163.5    1.1   260   25.9 
2026-05-04 00:00 UT   15 46 04.3   -13 07 22    13.763   14.737  164.5    1.0   258   25.9 
2026-05-05 00:00 UT   15 45 44.1   -13 06 31    13.764   14.742  165.4    1.0   256   25.9 
2026-05-06 00:00 UT   15 45 23.8   -13 05 40    13.765   14.747  166.4    0.9   254   25.9 
2026-05-07 00:00 UT   15 45 03.4   -13 04 49    13.766   14.753  167.3    0.9   252   25.9 
2026-05-08 00:00 UT   15 44 43.0   -13 03 58    13.768   14.758  168.2    0.8   250   25.9 
2026-05-09 00:00 UT   15 44 22.5   -13 03 07    13.770   14.763  169.0    0.7   246   25.9 
2026-05-10 00:00 UT   15 44 02.0   -13 02 17    13.773   14.768  169.9    0.7   243   25.9 
2026-05-11 00:00 UT   15 43 41.5   -13 01 27    13.775   14.773  170.6    0.6   239   25.9 

    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.