1P/Halley
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Today	11 Apr 2026	25.6	35.056 AU	34.836 AU	08h08m	+03°17'	101.9°	1.6°	99°
Nearest approach	6 Aug 2061	0.8	0.573 AU	0.496 AU	09h31m	+35°41'	19.9°	142.9°	20°
Perihelion	8 Aug 2061	1.0	0.571 AU	0.508 AU	10h21m	+30°13'	21.3°	139.9°	53°

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. (5.5 + 5 log[∆] + 8.0 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 1P/Halley are:

    e (Eccentricity)                : 0.9680070
    q (Perihelion distance)         : 0.5713420
    i (Inclination)                 : 162.17120
    Ω (Longitude of ascending node) : 59.41830
    ω (Argument of perihelion)      : 112.31730
    L (Longitude of perihelion)     : 126.09306
    B (Latitude of perihelion)      : 16.45367
    T (Time of perihelion passage)  : 2474044.74280
    P (Orbital period in years)     : 75.47

    Epoch                           : 2026 Apr 10
    Reference                       : MPC191592

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

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-04-10 00:00 UT   08 08 41.2   +03 16 42    34.812   35.056  103.3    1.6    99   25.6 
2026-04-11 00:00 UT   08 08 39.7   +03 17 16    34.827   35.056  102.4    1.6    99   25.6 
2026-04-11 12:36 UT   08 08 39.0   +03 17 34    34.836   35.056  101.9    1.6    99   25.6 
2026-04-12 00:00 UT   08 08 38.4   +03 17 50    34.843   35.055  101.4    1.6    99   25.6 
2026-04-13 00:00 UT   08 08 37.2   +03 18 23    34.859   35.055  100.5    1.6   100   25.6 
2026-04-14 00:00 UT   08 08 36.1   +03 18 56    34.875   35.055   99.5    1.6   100   25.6 
2026-04-15 00:00 UT   08 08 35.2   +03 19 29    34.891   35.055   98.6    1.6   100   25.6 
2026-04-16 00:00 UT   08 08 34.3   +03 20 01    34.907   35.055   97.6    1.6   100   25.6 
2026-04-17 00:00 UT   08 08 33.6   +03 20 33    34.923   35.054   96.7    1.6   101   25.6 
2026-04-18 00:00 UT   08 08 32.9   +03 21 05    34.939   35.054   95.8    1.6   101   25.6 
2026-04-19 00:00 UT   08 08 32.4   +03 21 36    34.955   35.054   94.8    1.6   101   25.6 
2026-04-20 00:00 UT   08 08 32.0   +03 22 07    34.972   35.054   93.9    1.6   102   25.6 
2026-04-21 00:00 UT   08 08 31.7   +03 22 37    34.988   35.054   92.9    1.6   102   25.6 

    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.