13P/Olbers
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	30 Jun 2024	6.5	1.175 AU	1.938 AU	08h28m	+42°23'	30.1°	25.7°	59°
Nearest approach	20 Jul 2024	6.7	1.214 AU	1.895 AU	10h17m	+39°22'	35.1°	28.8°	68°
Today	27 May 2025	19.8	4.205 AU	3.292 AU	18h24m	-26°59'	150.7°	6.8°	274°

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 13P/Olbers are:

            e (Eccentricity)                : 0.9304690
            q (Perihelion distance)         : 1.1754620
            i (Inclination)                 : 44.66580
            Ω (Longitude of ascending node) : 85.84670
            ω (Argument of perihelion)      : 64.42220
            L (Longitude of perihelion)     : 141.90654
            B (Latitude of perihelion)      : 39.35172
            T (Time of perihelion passage)  : 2460491.57340
            P (Orbital period in years)     : 69.51

            Epoch                           : 2025 May 26
            Reference                       : MPEC 2025-J92

            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. (3.50 + 5 log[∆] + 22.00 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
2025-05-27 00:00 UT   18 25 17.5   -26 54 46     3.291    4.198  149.8    7.0   274   19.8 
2025-05-27 18:44 UT   18 24 36.6   -26 59 01     3.292    4.205  150.7    6.8   274   19.8 
2025-05-28 00:00 UT   18 24 25.0   -27 00 12     3.293    4.207  150.9    6.7   274   19.8 
2025-05-29 00:00 UT   18 23 31.8   -27 05 36     3.294    4.217  152.1    6.5   275   19.8 
2025-05-30 00:00 UT   18 22 38.0   -27 10 57     3.296    4.226  153.2    6.2   275   19.9 
2025-05-31 00:00 UT   18 21 43.6   -27 16 16     3.298    4.235  154.3    5.9   276   19.9 
2025-06-01 00:00 UT   18 20 48.5   -27 21 32     3.301    4.244  155.5    5.7   277   19.9 
2025-06-02 00:00 UT   18 19 53.0   -27 26 46     3.303    4.253  156.6    5.4   278   19.9 
2025-06-03 00:00 UT   18 18 56.9   -27 31 57     3.306    4.263  157.8    5.2   278   19.9 
2025-06-04 00:00 UT   18 18 00.3   -27 37 04     3.310    4.272  158.9    4.9   279   20.0 
2025-06-05 00:00 UT   18 17 03.3   -27 42 09     3.313    4.281  160.0    4.6   280   20.0 
2025-06-06 00:00 UT   18 16 06.0   -27 47 10     3.317    4.290  161.1    4.4   281   20.0 

    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.