217P/LINEAR
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	25 May 2025	12.8	1.225 AU	2.005 AU	02h22m	+06°32'	29.1°	23.8°	238°
Nearest approach	2 Jan 2026	17.0	2.721 AU	1.838 AU	09h04m	+15°49'	147.9°	11.1°	288°
Today	19 May 2026	20.3	3.689 AU	3.941 AU	08h40m	+21°52'	68.3°	14.8°	103°

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. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 10.2 + 5 log[∆] + 12.6 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 217P/LINEAR are:

    e (Eccentricity)                : 0.6896840
    q (Perihelion distance)         : 1.2245950
    i (Inclination)                 : 12.87200
    Ω (Longitude of ascending node) : 125.37010
    ω (Argument of perihelion)      : 246.98780
    L (Longitude of perihelion)     : 191.82857
    B (Latitude of perihelion)      : -11.83218
    T (Time of perihelion passage)  : 2460820.56740
    P (Orbital period in years)     : 7.84

    Epoch                           : 2026 May 19
    Reference                       : MPEC 2026-HI3

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.548

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-05-18 00:00 UT   08 38 31.5   +21 57 39     3.904    3.677   69.7   14.9   103   20.2 
2026-05-19 00:00 UT   08 39 22.6   +21 55 06     3.925    3.683   68.9   14.8   103   20.3 
2026-05-19 19:47 UT   08 40 05.1   +21 52 58     3.941    3.689   68.3   14.8   103   20.3 
2026-05-20 00:00 UT   08 40 14.2   +21 52 31     3.945    3.690   68.1   14.7   103   20.3 
2026-05-21 00:00 UT   08 41 06.1   +21 49 52     3.965    3.696   67.4   14.6   103   20.3 
2026-05-22 00:00 UT   08 41 58.5   +21 47 11     3.985    3.703   66.6   14.5   104   20.3 
2026-05-23 00:00 UT   08 42 51.2   +21 44 28     4.005    3.709   65.9   14.4   104   20.3 
2026-05-24 00:00 UT   08 43 44.3   +21 41 42     4.025    3.715   65.1   14.3   104   20.4 
2026-05-25 00:00 UT   08 44 37.7   +21 38 54     4.045    3.721   64.4   14.2   104   20.4 
2026-05-26 00:00 UT   08 45 31.5   +21 36 03     4.065    3.728   63.6   14.1   104   20.4 
2026-05-27 00:00 UT   08 46 25.6   +21 33 10     4.085    3.734   62.9   14.0   104   20.4 
2026-05-28 00:00 UT   08 47 20.0   +21 30 14     4.105    3.740   62.2   13.9   104   20.4 
2026-05-29 00:00 UT   08 48 14.8   +21 27 16     4.124    3.747   61.4   13.7   104   20.5 

    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.