C/2019 LB7 (Kleyna)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	3 Dec 2018	22.7	2.763 AU	1.833 AU	04h04m	-00°24'	156.0°	8.3°	20°
Perihelion	28 Mar 2019	23.7	2.494 AU	3.446 AU	01h23m	+04°01'	14.7°	5.8°	85°
Today	21 Dec 2025	35.4	16.658 AU	17.538 AU	16h32m	-08°28'	25.7°	1.5°	308°

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. (17.0 + 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 LB7 (Kleyna) are:

    e (Eccentricity)                : 0.9288930
    q (Perihelion distance)         : 2.4935940
    i (Inclination)                 : 164.27460
    Ω (Longitude of ascending node) : 4.03600
    ω (Argument of perihelion)      : 336.80310
    L (Longitude of perihelion)     : 26.45201
    B (Latitude of perihelion)      : -6.12832
    T (Time of perihelion passage)  : 2458570.56730
    P (Orbital period in years)     : 207.67

    Epoch                           : 2025 Nov 12
    Reference                       : MPC118095

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-12-20 00:00 UT   16 31 56.0   -08 27 54    17.541   16.649   24.2    1.4   311   35.4 
2025-12-21 00:00 UT   16 32 07.1   -08 28 05    17.540   16.654   25.0    1.4   309   35.4 
2025-12-21 22:32 UT   16 32 17.5   -08 28 14    17.538   16.658   25.7    1.5   308   35.4 
2025-12-22 00:00 UT   16 32 18.1   -08 28 15    17.538   16.658   25.8    1.5   308   35.4 
2025-12-23 00:00 UT   16 32 29.1   -08 28 24    17.536   16.663   26.6    1.5   307   35.4 
2025-12-24 00:00 UT   16 32 39.9   -08 28 32    17.534   16.668   27.5    1.6   306   35.4 
2025-12-25 00:00 UT   16 32 50.7   -08 28 39    17.531   16.672   28.3    1.6   305   35.4 
2025-12-26 00:00 UT   16 33 01.3   -08 28 44    17.528   16.677   29.2    1.6   304   35.4 
2025-12-27 00:00 UT   16 33 11.9   -08 28 49    17.525   16.682   30.0    1.7   303   35.4 
2025-12-28 00:00 UT   16 33 22.4   -08 28 53    17.522   16.686   30.9    1.7   302   35.4 
2025-12-29 00:00 UT   16 33 32.7   -08 28 56    17.518   16.691   31.8    1.8   301   35.4 
2025-12-30 00:00 UT   16 33 43.0   -08 28 58    17.515   16.696   32.7    1.8   300   35.4 
2025-12-31 00:00 UT   16 33 53.1   -08 28 59    17.511   16.701   33.6    1.9   300   35.4 

    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.