P/2017 B4 (PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	20 Nov 2025	21.0	2.934 AU	2.299 AU	07h47m	+11°12'	121.1°	16.8°	286°
Nearest approach	16 Jan 2026	20.4	2.851 AU	1.872 AU	07h24m	+16°52'	172.4°	2.6°	56°
Perihelion	11 Apr 2026	21.1	2.801 AU	2.631 AU	07h32m	+25°46'	89.1°	21.0°	99°

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. The light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (14.5 + 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 P/2017 B4 (PANSTARRS) are:

    e (Eccentricity)                : 0.3649520
    q (Perihelion distance)         : 2.8008940
    i (Inclination)                 : 20.05840
    Ω (Longitude of ascending node) : 121.45780
    ω (Argument of perihelion)      : 11.01970
    L (Longitude of perihelion)     : 131.82403
    B (Latitude of perihelion)      : 3.75895
    T (Time of perihelion passage)  : 2457759.31780
    P (Orbital period in years)     : 9.26

    Epoch                           : 
    Reference                       : MPC103847

    Classification(s):              : Ecliptic; Jupiter family
    Tisserand (Jupiter)             : 2.790

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2025-11-19 00:00 UT   07 46 50.7   +11 08 50     2.322    2.937  119.5   17.0   286   21.0 
2025-11-20 00:00 UT   07 47 03.0   +11 10 40     2.309    2.935  120.4   16.9   286   21.0 
2025-11-20 17:03 UT   07 47 10.9   +11 12 03     2.299    2.934  121.1   16.8   286   21.0 
2025-11-21 00:00 UT   07 47 13.9   +11 12 38     2.295    2.934  121.4   16.7   287   21.0 
2025-11-22 00:00 UT   07 47 23.5   +11 14 43     2.282    2.932  122.3   16.5   287   21.0 
2025-11-23 00:00 UT   07 47 31.7   +11 16 57     2.269    2.930  123.3   16.4   287   20.9 
2025-11-24 00:00 UT   07 47 38.6   +11 19 18     2.256    2.928  124.3   16.2   287   20.9 
2025-11-25 00:00 UT   07 47 44.1   +11 21 48     2.243    2.927  125.3   16.0   287   20.9 
2025-11-26 00:00 UT   07 47 48.2   +11 24 26     2.231    2.925  126.2   15.8   288   20.9 
2025-11-27 00:00 UT   07 47 51.0   +11 27 13     2.218    2.923  127.2   15.6   288   20.9 
2025-11-28 00:00 UT   07 47 52.4   +11 30 08     2.206    2.921  128.2   15.4   288   20.9 
2025-11-29 00:00 UT   07 47 52.4   +11 33 12     2.194    2.920  129.2   15.2   288   20.9 
2025-11-30 00:00 UT   07 47 51.1   +11 36 24     2.182    2.918  130.3   14.9   289   20.8 

    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.