C/2019 Q1 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	22 Jul 2020	18.7	5.000 AU	4.445 AU	23h20m	+20°27'	117.8°	10.4°	232°
Nearest approach	3 Sep 2020	18.6	5.011 AU	4.088 AU	22h19m	+17°54'	153.5°	5.1°	163°
Today	3 Jan 2026	25.8	14.109 AU	14.823 AU	15h59m	-13°52'	42.1°	2.7°	289°

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)                : 1.0025150
    q (Perihelion distance)         : 5.0001140
    i (Inclination)                 : 155.71290
    Ω (Longitude of ascending node) : 42.47380
    ω (Argument of perihelion)      : 56.24260
    L (Longitude of perihelion)     : -11.27501
    B (Latitude of perihelion)      : 19.99643
    T (Time of perihelion passage)  : 2459052.97750

    Epoch                           : 2026 Jan 02
    Reference                       : MPEC 2024-EF7

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-01-02 00:00 UT   15 59 25.3   -13 52 19    14.830   14.104   41.0    2.6   289   25.8 
2026-01-03 00:00 UT   15 59 34.0   -13 52 48    14.824   14.109   42.0    2.7   289   25.8 
2026-01-03 01:33 UT   15 59 34.6   -13 52 50    14.823   14.109   42.1    2.7   289   25.8 
2026-01-04 00:00 UT   15 59 42.6   -13 53 16    14.817   14.114   43.0    2.7   289   25.9 
2026-01-05 00:00 UT   15 59 51.0   -13 53 42    14.810   14.119   44.0    2.8   288   25.9 
2026-01-06 00:00 UT   15 59 59.2   -13 54 08    14.803   14.125   44.9    2.8   288   25.9 
2026-01-07 00:00 UT   16 00 07.2   -13 54 33    14.796   14.130   45.9    2.9   288   25.9 
2026-01-08 00:00 UT   16 00 15.0   -13 54 57    14.789   14.135   46.9    2.9   288   25.9 
2026-01-09 00:00 UT   16 00 22.7   -13 55 20    14.781   14.140   47.8    3.0   287   25.9 
2026-01-10 00:00 UT   16 00 30.1   -13 55 42    14.773   14.145   48.8    3.0   287   25.9 
2026-01-11 00:00 UT   16 00 37.4   -13 56 03    14.765   14.151   49.8    3.0   287   25.9 
2026-01-12 00:00 UT   16 00 44.4   -13 56 23    14.757   14.156   50.8    3.1   287   25.9 
2026-01-13 00:00 UT   16 00 51.2   -13 56 42    14.748   14.161   51.8    3.1   287   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.