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°	8.4°	20°
Perihelion	28 Mar 2019	23.7	2.492 AU	3.446 AU	01h24m	+04°05'	14.4°	5.7°	86°
Today	1 May 2026	35.4	17.264 AU	16.381 AU	16h29m	-07°00'	150.4°	1.7°	252°

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)                : 0.9289830
    q (Perihelion distance)         : 2.4918490
    i (Inclination)                 : 164.27080
    Ω (Longitude of ascending node) : 4.06350
    ω (Argument of perihelion)      : 336.81810
    L (Longitude of perihelion)     : 26.46452
    B (Latitude of perihelion)      : -6.12601
    T (Time of perihelion passage)  : 2458571.00760
    P (Orbital period in years)     : 207.84

    Epoch                           : 2026 Mar 16
    Reference                       : MPEC 2026-E44

    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
2026-04-30 00:00 UT   16 30 22.4   -07 02 04    16.386   17.257  149.0    1.7   253   35.4 
2026-05-01 00:00 UT   16 30 08.1   -07 01 09    16.382   17.261  149.9    1.7   252   35.4 
2026-05-01 14:13 UT   16 29 59.6   -07 00 36    16.381   17.264  150.4    1.7   252   35.4 
2026-05-02 00:00 UT   16 29 53.7   -07 00 14    16.379   17.266  150.7    1.6   251   35.4 
2026-05-03 00:00 UT   16 29 39.2   -06 59 20    16.377   17.271  151.6    1.6   250   35.4 
2026-05-04 00:00 UT   16 29 24.5   -06 58 26    16.374   17.275  152.5    1.5   249   35.4 
2026-05-05 00:00 UT   16 29 09.8   -06 57 33    16.372   17.280  153.4    1.5   248   35.4 
2026-05-06 00:00 UT   16 28 55.0   -06 56 40    16.370   17.284  154.2    1.5   246   35.4 
2026-05-07 00:00 UT   16 28 40.0   -06 55 48    16.369   17.289  155.0    1.4   245   35.4 
2026-05-08 00:00 UT   16 28 25.0   -06 54 56    16.367   17.293  155.8    1.4   243   35.4 
2026-05-09 00:00 UT   16 28 09.9   -06 54 05    16.366   17.298  156.6    1.3   242   35.4 
2026-05-10 00:00 UT   16 27 54.6   -06 53 15    16.366   17.303  157.4    1.3   240   35.5 
2026-05-11 00:00 UT   16 27 39.3   -06 52 26    16.365   17.307  158.2    1.2   238   35.5 

    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.