C/2019 Q1 (Lemmon)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	22 Jul 2020	18.7	4.998 AU	4.440 AU	23h20m	+20°28'	117.9°	10.3°	232°
Nearest approach	3 Sep 2020	18.6	5.008 AU	4.085 AU	22h19m	+17°55'	153.5°	5.2°	163°
Today	18 May 2026	25.9	14.811 AU	13.805 AU	15h41m	-12°55'	173.4°	0.4°	185°

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)                : 1.0025200
    q (Perihelion distance)         : 4.9975760
    i (Inclination)                 : 155.70530
    Ω (Longitude of ascending node) : 42.47900
    ω (Argument of perihelion)      : 56.22640
    L (Longitude of perihelion)     : 348.74854
    B (Latitude of perihelion)      : 19.99861
    T (Time of perihelion passage)  : 2459053.13660

    Epoch                           : 2026 May 17
    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
2026-05-17 00:00 UT   15 41 37.7   -12 56 33    13.799   14.804  173.5    0.4   197   25.9 
2026-05-18 00:00 UT   15 41 17.1   -12 55 46    13.804   14.809  173.5    0.4   187   25.9 
2026-05-18 07:00 UT   15 41 11.1   -12 55 32    13.805   14.811  173.4    0.4   185   25.9 
2026-05-19 00:00 UT   15 40 56.5   -12 54 59    13.809   14.814  173.3    0.5   179   25.9 
2026-05-20 00:00 UT   15 40 35.8   -12 54 12    13.815   14.820  172.9    0.5   170   25.9 
2026-05-21 00:00 UT   15 40 15.3   -12 53 26    13.820   14.825  172.5    0.5   163   25.9 
2026-05-22 00:00 UT   15 39 54.7   -12 52 40    13.827   14.830  171.9    0.6   156   25.9 
2026-05-23 00:00 UT   15 39 34.2   -12 51 55    13.833   14.835  171.3    0.6   151   25.9 
2026-05-24 00:00 UT   15 39 13.8   -12 51 10    13.840   14.840  170.5    0.6   146   25.9 
2026-05-25 00:00 UT   15 38 53.3   -12 50 26    13.847   14.845  169.7    0.7   142   25.9 
2026-05-26 00:00 UT   15 38 33.0   -12 49 42    13.855   14.851  168.9    0.8   139   25.9 
2026-05-27 00:00 UT   15 38 12.7   -12 48 59    13.863   14.856  168.1    0.8   136   25.9 
2026-05-28 00:00 UT   15 37 52.5   -12 48 16    13.871   14.861  167.2    0.9   133   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.