C/2019 Q1 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	22 Jul 2020	18.7	4.996 AU	4.439 AU	23h20m	+20°29'	117.9°	10.4°	232°
Nearest approach	3 Sep 2020	18.6	5.007 AU	4.084 AU	22h19m	+17°56'	153.5°	5.2°	163°
Today	17 Aug 2026	26.3	15.281 AU	15.307 AU	15h20m	-12°40'	86.6°	3.8°	104°

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)                : 1.0024670
    q (Perihelion distance)         : 4.9958610
    i (Inclination)                 : 155.70030
    Ω (Longitude of ascending node) : 42.48220
    ω (Argument of perihelion)      : 56.21330
    L (Longitude of perihelion)     : 348.76634
    B (Latitude of perihelion)      : 19.99946
    T (Time of perihelion passage)  : 2459053.16560

    Epoch                           : 2026 Aug 13
    Reference                       : MPC194163

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-08-16 00:00 UT   15 20 53.6   -12 39 30    15.267   15.272   88.4    3.8   105   26.3 
2026-08-17 00:00 UT   15 20 51.0   -12 40 03    15.289   15.277   87.4    3.8   105   26.3 
2026-08-17 19:30 UT   15 20 49.1   -12 40 31    15.307   15.281   86.6    3.8   104   26.3 
2026-08-18 00:00 UT   15 20 48.6   -12 40 38    15.311   15.282   86.4    3.8   104   26.3 
2026-08-19 00:00 UT   15 20 46.6   -12 41 13    15.333   15.287   85.5    3.8   104   26.3 
2026-08-20 00:00 UT   15 20 44.8   -12 41 48    15.355   15.292   84.5    3.8   104   26.3 
2026-08-21 00:00 UT   15 20 43.2   -12 42 25    15.378   15.297   83.5    3.8   104   26.3 
2026-08-22 00:00 UT   15 20 42.0   -12 43 03    15.400   15.303   82.6    3.8   104   26.3 
2026-08-23 00:00 UT   15 20 40.9   -12 43 41    15.422   15.308   81.6    3.7   104   26.3 
2026-08-24 00:00 UT   15 20 40.2   -12 44 20    15.444   15.313   80.7    3.7   104   26.3 
2026-08-25 00:00 UT   15 20 39.7   -12 45 00    15.466   15.318   79.7    3.7   104   26.3 
2026-08-26 00:00 UT   15 20 39.4   -12 45 41    15.488   15.323   78.7    3.7   104   26.3 
2026-08-27 00:00 UT   15 20 39.4   -12 46 22    15.509   15.328   77.8    3.7   104   26.3 

    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.