2021 SF1
ephemeris	date	magn	radius	delta	ra	dec	elong	phase
Today	12 May 2026	27.7	1.365 AU	0.481 AU	18h51m	-21°23'	129.0°	35.1°

The interactive orbit chart above shows the body'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 2021 SF1 are:

            e (Eccentricity)                : 0.1677477
            a (Semimajor axis)              : 1.1717045
            i (Inclination)                 : 0.79407
            Ω (Longitude of ascending node) : 204.29908
            ω (Argument of perihelion)      : 213.28442
            M (Mean anomaly)                : 59.09265
            Epoch                           : 2025 Nov 21

            L (Longitude of perihelion)     : 237.58098
            B (Latitude of perihelion)      : -0.43577
            P (Orbital period in years)     : 1.27            
        

The light curve chart below shows the estimated development of the minor planet's magnitude.

The all-sky chart below shows the path of the minor planet over the same period as the light curve. The current position is marked yellow.

The following chart shows the path of the minor planet in the next few days. The field of view is optimized for (~10x50) binoculars and finderscopes.

Ephemerides:

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-05-12 00:00 UT   18 51 18.3   -21 23 31     0.481    1.365  129.0   35.1   264   27.7 
2026-05-12 16:26 UT   18 51 31.8   -21 21 47     0.477    1.364  129.6   34.8   264   27.7 
2026-05-13 00:00 UT   18 51 37.5   -21 21 00     0.475    1.364  129.9   34.6   264   27.7 
2026-05-14 00:00 UT   18 51 53.1   -21 18 32     0.469    1.364  130.8   34.1   264   27.6 
2026-05-15 00:00 UT   18 52 04.8   -21 16 07     0.463    1.363  131.7   33.6   263   27.6 
2026-05-16 00:00 UT   18 52 12.7   -21 13 45     0.457    1.363  132.6   33.1   263   27.6 
2026-05-17 00:00 UT   18 52 16.7   -21 11 26     0.452    1.362  133.6   32.5   263   27.5 
2026-05-18 00:00 UT   18 52 16.6   -21 09 10     0.446    1.362  134.5   32.0   263   27.5 
2026-05-19 00:00 UT   18 52 12.5   -21 06 58     0.440    1.361  135.5   31.4   263   27.4 
2026-05-20 00:00 UT   18 52 04.2   -21 04 49     0.435    1.360  136.5   30.8   263   27.4 
2026-05-21 00:00 UT   18 51 51.7   -21 02 44     0.429    1.360  137.5   30.2   263   27.3 
2026-05-22 00:00 UT   18 51 35.0   -21 00 43     0.424    1.359  138.5   29.6   263   27.3 
2026-05-23 00:00 UT   18 51 13.9   -20 58 45     0.419    1.358  139.5   28.9   263   27.2 
2026-05-24 00:00 UT   18 50 48.5   -20 56 52     0.413    1.358  140.6   28.3   263   27.2 
2026-05-25 00:00 UT   18 50 18.7   -20 55 02     0.408    1.357  141.7   27.6   262   27.1 
2026-05-26 00:00 UT   18 49 44.4   -20 53 15     0.403    1.356  142.8   26.9   262   27.1 
2026-05-27 00:00 UT   18 49 05.6   -20 51 33     0.398    1.355  143.9   26.2   262   27.0 
2026-05-28 00:00 UT   18 48 22.3   -20 49 54     0.393    1.354  145.0   25.4   262   27.0 
2026-05-29 00:00 UT   18 47 34.3   -20 48 19     0.389    1.354  146.1   24.7   262   26.9 
2026-05-30 00:00 UT   18 46 41.7   -20 46 48     0.384    1.353  147.3   23.9   262   26.9 
2026-05-31 00:00 UT   18 45 44.4   -20 45 19     0.379    1.352  148.4   23.1   262   26.8 
2026-06-01 00:00 UT   18 44 42.3   -20 43 54     0.375    1.351  149.6   22.3   262   26.8 
2026-06-02 00:00 UT   18 43 35.6   -20 42 32     0.371    1.350  150.8   21.5   261   26.7 
2026-06-03 00:00 UT   18 42 24.1   -20 41 14     0.366    1.349  152.1   20.6   261   26.7 
2026-06-04 00:00 UT   18 41 07.9   -20 39 57     0.362    1.348  153.3   19.7   261   26.6 
2026-06-05 00:00 UT   18 39 46.9   -20 38 44     0.358    1.347  154.6   18.9   261   26.6 
2026-06-06 00:00 UT   18 38 21.2   -20 37 32     0.354    1.346  155.9   18.0   261   26.5 
2026-06-07 00:00 UT   18 36 50.8   -20 36 23     0.350    1.345  157.2   17.0   260   26.5 
2026-06-08 00:00 UT   18 35 15.8   -20 35 16     0.347    1.344  158.5   16.1   260   26.4 
2026-06-09 00:00 UT   18 33 36.2   -20 34 10     0.343    1.342  159.8   15.1   259   26.3 
2026-06-10 00:00 UT   18 31 52.1   -20 33 05     0.340    1.341  161.1   14.2   259   26.3 
2026-06-11 00:00 UT   18 30 03.7   -20 32 02     0.336    1.340  162.5   13.2   258   26.2 

    Terminology:
            
    delta:  distance between minor planet and earth in AU
    radius: distance between minor planet 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-minor planet)    
    phase:  phase angle in degrees (angle sun-minor planet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km
    

Orbital elements provided by 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.