C/2017 D2 (Barros)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Perihelion	14 Jul 2017	15.4	2.500 AU	1.595 AU	22h01m	-33°53'	145.6°	13.3°	281°
Nearest approach	7 Aug 2017	15.3	2.514 AU	1.520 AU	21h39m	-29°21'	165.3°	5.9°	330°
Today	26 Dec 2024	29.6	19.259 AU	18.411 AU	05h38m	+53°28'	148.8°	1.5°	160°

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 C/2017 D2 (Barros) are:

            e (Eccentricity)                : 0.9998490
            q (Perihelion distance)         : 2.5000880
            i (Inclination)                 : 31.25650
            Ω (Longitude of ascending node) : 330.95930
            ω (Argument of perihelion)      : 334.65390
            L (Longitude of perihelion)     : 308.91485
            B (Latitude of perihelion)      : -12.83362
            T (Time of perihelion passage)  : 2457948.99800

            Epoch                           : 2022 Jul 23
            Reference                       : MPC112391

            Classification(s):              : Nearly isotropic; New (a > 10000 AU)
        

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 (11.00 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 10.40 + 5 log[∆] + 10.00 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
2024-12-26 00:00 UT   05 38 13.3   +53 29 06    18.407   19.256  148.9    1.5   162   29.6 
2024-12-26 14:21 UT   05 38 01.9   +53 28 49    18.411   19.259  148.8    1.5   160   29.6 
2024-12-27 00:00 UT   05 37 54.2   +53 28 38    18.414   19.261  148.6    1.5   160   29.6 
2024-12-28 00:00 UT   05 37 35.2   +53 28 07    18.422   19.266  148.4    1.5   158   29.6 
2024-12-29 00:00 UT   05 37 16.3   +53 27 34    18.430   19.272  148.0    1.5   156   29.6 
2024-12-30 00:00 UT   05 36 57.5   +53 26 60    18.438   19.277  147.7    1.6   154   29.6 
2024-12-31 00:00 UT   05 36 38.9   +53 26 24    18.446   19.282  147.3    1.6   152   29.6 
2025-01-01 00:00 UT   05 36 20.3   +53 25 46    18.455   19.287  146.9    1.6   150   29.6 
2025-01-02 00:00 UT   05 36 01.9   +53 25 06    18.464   19.292  146.5    1.6   148   29.6 
2025-01-03 00:00 UT   05 35 43.7   +53 24 25    18.474   19.297  146.0    1.6   146   29.6 
2025-01-04 00:00 UT   05 35 25.5   +53 23 41    18.483   19.303  145.5    1.7   145   29.6 
2025-01-05 00:00 UT   05 35 07.6   +53 22 56    18.493   19.308  145.0    1.7   143   29.6 

    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.