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 Apr 2025	23.1	1.283 AU	0.961 AU	21h20m	-44°27'	81.5°	50.7°	245°

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.)

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
        

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 gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (9.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 21.00 + 5 log[∆] + 20.00 log[r]). The additional green curve shows the effect of forward scattering, occurring when the comet is between the earth and the sun, for a gas-to-dust light ratio δ90 of 0.30. (See Marcus 2007)

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
2025-04-18 00:00 UT   21 21 54.2   -44 06 19     0.961    1.271   80.5   51.2   245   23.0 
2025-04-18 16:00 UT   21 20 33.8   -44 27 02     0.961    1.283   81.5   50.7   245   23.1 
2025-04-19 00:00 UT   21 19 52.9   -44 37 24     0.961    1.289   82.0   50.5   246   23.1 
2025-04-20 00:00 UT   21 17 46.5   -45 08 35     0.961    1.307   83.4   49.8   246   23.2 
2025-04-21 00:00 UT   21 15 34.9   -45 39 50     0.961    1.326   84.8   49.0   247   23.4 
2025-04-22 00:00 UT   21 13 17.6   -46 11 09     0.960    1.344   86.2   48.3   248   23.5 
2025-04-23 00:00 UT   21 10 54.4   -46 42 32     0.960    1.361   87.6   47.6   249   23.6 
2025-04-24 00:00 UT   21 08 24.9   -47 13 58     0.960    1.379   89.1   46.8   250   23.7 
2025-04-25 00:00 UT   21 05 48.7   -47 45 24     0.960    1.397   90.5   46.1   251   23.8 
2025-04-26 00:00 UT   21 03 05.6   -48 16 50     0.960    1.414   91.9   45.3   252   23.9 
2025-04-27 00:00 UT   21 00 15.2   -48 48 14     0.960    1.432   93.4   44.6   253   24.0 
2025-04-28 00:00 UT   20 57 17.3   -49 19 33     0.960    1.449   94.8   43.8   254   24.1 

    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.