C/2021 A10 (NEOWISE)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	9 Feb 2021	19.1	1.359 AU	0.572 AU	12h37m	+68°01'	118.9°	39.4°	233°
Perihelion	15 Mar 2021	20.6	1.264 AU	1.312 AU	02h59m	+44°54'	64.7°	45.4°	58°
Today	8 May 2024	34.5	10.783 AU	11.012 AU	22h53m	-27°07'	74.3°	5.2°	241°

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/2021 A10 (NEOWISE) are:

            e (Eccentricity)                : 0.9858720
            q (Perihelion distance)         : 1.2635680
            i (Inclination)                 : 151.95700
            Ω (Longitude of ascending node) : 188.75630
            ω (Argument of perihelion)      : 82.51840
            L (Longitude of perihelion)     : 107.21954
            B (Latitude of perihelion)      : 27.78349
            T (Time of perihelion passage)  : 2459288.50170
            P (Orbital period in years)     : 845.82

            Epoch                           : 2024 May 07
            Reference                       : MPEC 2021-N06

            Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (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 based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (19.00 + 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
2024-05-08 00:00 UT   22 53 52.1   -27 07 39    11.012   10.783   74.3    5.2   241   34.5 
2024-05-08 00:04 UT   22 53 52.1   -27 07 40    11.012   10.783   74.3    5.2   241   34.5 
2024-05-09 00:00 UT   22 53 58.2   -27 09 11    11.003   10.790   75.2    5.2   241   34.5 
2024-05-10 00:00 UT   22 54 04.0   -27 10 45    10.994   10.797   76.1    5.2   242   34.5 
2024-05-11 00:00 UT   22 54 09.5   -27 12 22    10.985   10.804   77.0    5.2   242   34.5 
2024-05-12 00:00 UT   22 54 14.6   -27 14 01    10.976   10.810   77.9    5.2   242   34.5 
2024-05-13 00:00 UT   22 54 19.3   -27 15 43    10.966   10.817   78.9    5.3   242   34.5 
2024-05-14 00:00 UT   22 54 23.7   -27 17 28    10.957   10.824   79.8    5.3   243   34.5 
2024-05-15 00:00 UT   22 54 27.8   -27 19 15    10.948   10.830   80.7    5.3   243   34.5 
2024-05-16 00:00 UT   22 54 31.5   -27 21 06    10.938   10.837   81.6    5.3   243   34.5 
2024-05-17 00:00 UT   22 54 34.9   -27 22 58    10.929   10.844   82.5    5.3   244   34.5 
2024-05-18 00:00 UT   22 54 37.9   -27 24 53    10.919   10.850   83.4    5.3   244   34.5 

    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.