381P/LINEAR-Spacewatch
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	8 Sep 2019	19.9	2.288 AU	1.292 AU	22h31m	+01°55'	168.5°	5.0°	133°
Perihelion	25 Sep 2019	19.9	2.282 AU	1.332 AU	22h29m	-04°05'	155.4°	10.5°	79°
Today	16 Apr 2025	27.6	10.474 AU	9.990 AU	09h26m	+01°03'	116.4°	4.9°	102°

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.)

The orbital elements of 381P/LINEAR-Spacewatch are:

            e (Eccentricity)                : 0.6805970
            q (Perihelion distance)         : 2.2821550
            i (Inclination)                 : 28.33920
            Ω (Longitude of ascending node) : 173.31860
            ω (Argument of perihelion)      : 173.85000
            L (Longitude of perihelion)     : 167.90098
            B (Latitude of perihelion)      : 2.91500
            T (Time of perihelion passage)  : 2458751.77460
            P (Orbital period in years)     : 19.10

            Epoch                           : 2025 Apr 15
            Reference                       : MPEC 2021-J28

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

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC. 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. (17.50 + 5 log[∆] + 5.00 log[r]).

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.
A more printer-friendly version of the same chart can be found further down this page as well.

The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.

A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-04-16 00:00 UT   09 26 38.0   +01 01 45     9.979   10.473  117.0    4.9   102   27.6 
2025-04-16 15:18 UT   09 26 35.1   +01 03 06     9.990   10.474  116.4    4.9   102   27.6 
2025-04-17 00:00 UT   09 26 33.6   +01 03 52     9.996   10.475  116.0    4.9   102   27.6 
2025-04-18 00:00 UT   09 26 29.6   +01 05 58    10.013   10.477  115.0    5.0   102   27.6 
2025-04-19 00:00 UT   09 26 25.9   +01 08 03    10.029   10.479  114.1    5.0   103   27.6 
2025-04-20 00:00 UT   09 26 22.6   +01 10 05    10.046   10.481  113.1    5.1   103   27.6 
2025-04-21 00:00 UT   09 26 19.7   +01 12 06    10.063   10.484  112.1    5.1   103   27.6 
2025-04-22 00:00 UT   09 26 17.1   +01 14 06    10.081   10.486  111.2    5.1   103   27.6 
2025-04-23 00:00 UT   09 26 14.9   +01 16 03    10.098   10.488  110.2    5.2   104   27.6 
2025-04-24 00:00 UT   09 26 13.1   +01 17 59    10.115   10.490  109.2    5.2   104   27.6 
2025-04-25 00:00 UT   09 26 11.7   +01 19 54    10.133   10.492  108.3    5.2   104   27.6 
2025-04-26 00:00 UT   09 26 10.6   +01 21 46    10.151   10.494  107.3    5.3   105   27.6 

    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.