381P/LINEAR-Spacewatch
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	8 Sep 2019	19.9	2.289 AU	1.293 AU	22h33m	+02°08'	168.6°	5.0°	134°
Perihelion	24 Sep 2019	19.9	2.285 AU	1.326 AU	22h31m	-03°22'	157.2°	9.8°	81°
Today	26 Nov 2025	27.9	10.920 AU	10.932 AU	10h20m	-01°40'	86.7°	5.2°	291°

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. (17.5 + 5 log[∆] + 5.0 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 381P/LINEAR-Spacewatch are:

    e (Eccentricity)                : 0.6802670
    q (Perihelion distance)         : 2.2845870
    i (Inclination)                 : 28.32610
    Ω (Longitude of ascending node) : 173.82990
    ω (Argument of perihelion)      : 173.34040
    L (Longitude of perihelion)     : 167.96177
    B (Latitude of perihelion)      : 3.15439
    T (Time of perihelion passage)  : 2458750.71500
    P (Orbital period in years)     : 19.10

    Epoch                           : 2025 Nov 25
    Reference                       : MPEC 2025-W75

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.240

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-11-25 00:00 UT   10 19 59.1   -01 38 45    10.954   10.917   85.3    5.2   291   27.9 
2025-11-26 00:00 UT   10 20 02.6   -01 39 45    10.939   10.919   86.2    5.2   291   27.9 
2025-11-26 11:43 UT   10 20 04.1   -01 40 14    10.932   10.920   86.7    5.2   291   27.9 
2025-11-27 00:00 UT   10 20 05.6   -01 40 44    10.924   10.920   87.2    5.2   291   27.9 
2025-11-28 00:00 UT   10 20 08.3   -01 41 40    10.909   10.922   88.2    5.2   291   27.9 
2025-11-29 00:00 UT   10 20 10.7   -01 42 34    10.894   10.924   89.2    5.2   291   27.9 
2025-11-30 00:00 UT   10 20 12.7   -01 43 27    10.879   10.926   90.1    5.2   292   27.9 
2025-12-01 00:00 UT   10 20 14.4   -01 44 18    10.864   10.928   91.1    5.2   292   27.9 
2025-12-02 00:00 UT   10 20 15.7   -01 45 06    10.849   10.929   92.1    5.2   292   27.9 
2025-12-03 00:00 UT   10 20 16.7   -01 45 53    10.834   10.931   93.1    5.2   292   27.9 
2025-12-04 00:00 UT   10 20 17.3   -01 46 37    10.819   10.933   94.1    5.2   292   27.9 
2025-12-05 00:00 UT   10 20 17.5   -01 47 20    10.804   10.935   95.1    5.2   293   27.9 
2025-12-06 00:00 UT   10 20 17.4   -01 48 00    10.789   10.937   96.1    5.1   293   27.9 

    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.