12P/Pons-Brooks
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	21 Apr 2024	3.7	0.781 AU	1.606 AU	03h28m	+09°50'	22.7°	29.7°	97°
Nearest approach	2 Jun 2024	5.5	1.099 AU	1.546 AU	05h52m	-19°31'	45.2°	40.9°	157°
Today	28 May 2025	16.0	5.100 AU	4.185 AU	16h06m	-49°40'	151.7°	5.4°	7°

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 12P/Pons-Brooks are:

            e (Eccentricity)                : 0.9546600
            q (Perihelion distance)         : 0.7810950
            i (Inclination)                 : 74.18970
            Ω (Longitude of ascending node) : 255.85650
            ω (Argument of perihelion)      : 199.00630
            L (Longitude of perihelion)     : 261.21782
            B (Latitude of perihelion)      : -18.26133
            T (Time of perihelion passage)  : 2460421.63830
            P (Orbital period in years)     : 71.50

            Epoch                           : 2025 May 27
            Reference                       : MPEC 2025-J08

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

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 estimated manually by the author. (4.00 + 5 log[∆] + 12.50 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
2025-05-28 00:00 UT   16 07 02.0   -49 41 57     4.183    5.097  151.6    5.4     6   15.9 
2025-05-28 06:49 UT   16 06 41.1   -49 40 10     4.185    5.100  151.7    5.4     7   16.0 
2025-05-29 00:00 UT   16 05 48.4   -49 35 38     4.190    5.106  151.8    5.4     8   16.0 
2025-05-30 00:00 UT   16 04 35.6   -49 29 12     4.199    5.115  151.9    5.4    11   16.0 
2025-05-31 00:00 UT   16 03 23.4   -49 22 38     4.207    5.124  151.9    5.3    14   16.0 
2025-06-01 00:00 UT   16 02 12.1   -49 15 56     4.216    5.133  152.0    5.3    16   16.0 
2025-06-02 00:00 UT   16 01 01.5   -49 09 07     4.225    5.142  151.9    5.3    19   16.0 
2025-06-03 00:00 UT   15 59 51.8   -49 02 11     4.234    5.151  151.9    5.3    22   16.0 
2025-06-04 00:00 UT   15 58 43.1   -48 55 08     4.244    5.160  151.8    5.3    24   16.0 
2025-06-05 00:00 UT   15 57 35.2   -48 47 58     4.254    5.169  151.6    5.4    27   16.1 
2025-06-06 00:00 UT   15 56 28.3   -48 40 43     4.264    5.178  151.4    5.4    30   16.1 
2025-06-07 00:00 UT   15 55 22.3   -48 33 21     4.275    5.187  151.2    5.4    32   16.1 

    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.