249P/LINEAR
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	24 Jan 2025	15.8	0.533 AU	1.469 AU	19h41m	-19°36'	10.6°	19.8°	270°
Perihelion	1 Feb 2025	15.6	0.500 AU	1.479 AU	20h47m	-15°15'	3.8°	7.4°	298°
Today	17 Oct 2025	25.2	3.213 AU	3.040 AU	07h38m	+16°08'	90.8°	18.1°	280°

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 17.8 + 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 249P/LINEAR are:

    e (Eccentricity)                : 0.8194330
    q (Perihelion distance)         : 0.4998030
    i (Inclination)                 : 8.37640
    Ω (Longitude of ascending node) : 239.00580
    ω (Argument of perihelion)      : 65.81330
    L (Longitude of perihelion)     : 304.58862
    B (Latitude of perihelion)      : 7.63648
    T (Time of perihelion passage)  : 2460708.23320
    P (Orbital period in years)     : 4.61

    Epoch                           : 2025 Oct 17
    Reference                       : MPEC 2022-YN2

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.707

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-10-16 00:00 UT   07 38 11.0   +16 13 47     3.058    3.199   88.9   18.2   279   25.2 
2025-10-17 00:00 UT   07 38 21.1   +16 11 03     3.049    3.206   89.9   18.1   280   25.2 
2025-10-17 23:58 UT   07 38 29.9   +16 08 22     3.040    3.213   90.8   18.1   280   25.2 
2025-10-18 00:00 UT   07 38 29.9   +16 08 22     3.040    3.213   90.8   18.1   280   25.2 
2025-10-19 00:00 UT   07 38 37.3   +16 05 43     3.032    3.220   91.8   18.0   280   25.2 
2025-10-20 00:00 UT   07 38 43.5   +16 03 06     3.023    3.227   92.7   18.0   280   25.2 
2025-10-21 00:00 UT   07 38 48.3   +16 00 32     3.014    3.234   93.7   17.9   280   25.2 
2025-10-22 00:00 UT   07 38 51.8   +15 58 00     3.005    3.241   94.7   17.8   280   25.2 
2025-10-23 00:00 UT   07 38 53.9   +15 55 31     2.996    3.248   95.6   17.7   280   25.2 
2025-10-24 00:00 UT   07 38 54.7   +15 53 05     2.987    3.255   96.6   17.7   280   25.3 
2025-10-25 00:00 UT   07 38 54.2   +15 50 41     2.978    3.263   97.6   17.6   280   25.3 
2025-10-26 00:00 UT   07 38 52.2   +15 48 21     2.970    3.270   98.6   17.5   280   25.3 
2025-10-27 00:00 UT   07 38 48.9   +15 46 03     2.961    3.277   99.6   17.4   281   25.3 

    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.