P/2008 Y12 (SOHO)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	3 Mar 2025	-2.6	0.068 AU	0.974 AU	23h08m	-04°20'	3.8°	102.8°	51°
Nearest approach	8 Mar 2025	8.8	0.265 AU	0.850 AU	22h41m	-15°59'	13.9°	115.4°	217°
Today	18 Nov 2025	35.7	3.717 AU	4.566 AU	17h13m	-36°28'	27.4°	7.0°	122°

This comet is a sunskirter. Although it may become very bright at perihelion, this will only be for a very short period very close to the sun.

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 21.0 + 5 log[∆] + 20.0 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 P/2008 Y12 (SOHO) are:

    e (Eccentricity)                : 0.9780940
    q (Perihelion distance)         : 0.0674140
    i (Inclination)                 : 23.67710
    Ω (Longitude of ascending node) : 309.72500
    ω (Argument of perihelion)      : 144.45540
    L (Longitude of perihelion)     : 276.52721
    B (Latitude of perihelion)      : 13.50052
    T (Time of perihelion passage)  : 2458766.22530
    P (Orbital period in years)     : 5.40

    Epoch                           : 2019 May 14
    Reference                       : MPC 88693

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); Halley type (P < 200 years); Sunskirter

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-11-17 00:00 UT   17 11 46.7   -36 28 57     4.540    3.703   28.6    7.4   121   35.7 
2025-11-18 00:00 UT   17 12 56.0   -36 28 51     4.555    3.711   28.0    7.2   122   35.7 
2025-11-18 18:39 UT   17 13 49.9   -36 28 47     4.566    3.717   27.4    7.0   122   35.7 
2025-11-19 00:00 UT   17 14 05.3   -36 28 46     4.569    3.718   27.3    7.0   122   35.7 
2025-11-20 00:00 UT   17 15 14.6   -36 28 41     4.583    3.726   26.6    6.8   123   35.7 
2025-11-21 00:00 UT   17 16 23.9   -36 28 37     4.597    3.734   26.0    6.6   124   35.8 
2025-11-22 00:00 UT   17 17 33.2   -36 28 34     4.611    3.742   25.3    6.5   125   35.8 
2025-11-23 00:00 UT   17 18 42.5   -36 28 32     4.624    3.749   24.6    6.3   125   35.8 
2025-11-24 00:00 UT   17 19 51.7   -36 28 31     4.637    3.757   24.0    6.1   126   35.8 
2025-11-25 00:00 UT   17 21 00.9   -36 28 30     4.650    3.765   23.3    6.0   127   35.9 
2025-11-26 00:00 UT   17 22 10.1   -36 28 30     4.663    3.772   22.7    5.8   128   35.9 
2025-11-27 00:00 UT   17 23 19.2   -36 28 30     4.676    3.780   22.1    5.6   129   35.9 
2025-11-28 00:00 UT   17 24 28.3   -36 28 31     4.688    3.787   21.5    5.5   130   35.9 

    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.