2021 BJ
ephemeris	date	magn	radius	delta (AU)	delta (LD)	delta (km)	ra	dec	elong	phase
Brightest	7 Nov 2024	22.9	1.005 AU	0.087 AU	33.82 LD	13,003,799 km	21h18m	+01°57'	96.7°	78.4°
Approach	29 Nov 2024	25.8	0.949 AU	0.047 AU	18.18 LD	6,988,345 km	17h31m	+10°37'	36.4°	141.9°
Today	4 Dec 2024	26.4	0.945 AU	0.050 AU	19.26 LD	7,405,412 km	16h15m	+10°34'	33.4°	144.9°

Based on its absolute magnitude (Hₒ) of 25.5 and an albedo between 0.25 and 0.05, the estimated diameter of 2021 BJ is 20 - 50 m.

The interactive orbit chart above shows the near-earth object'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 light curve chart below shows the estimated development of the NEO's magnitude during its approach to earth.

The following all-sky chart shows the path of the NEO in the coming months.

The following chart shows the path of the NEO in the coming days or hours. The field of view is optimized for (~10x50) binoculars and finderscopes. A more printer-friendly version of the same chart can be found below.

    Terminology:
            
    delta:  distance between NEO and earth in AU or LD 
    radius: distance between NEO 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-NEO)    
    phase:  phase angle in degrees (angle sun-NEO-earth)        
    AU:     Astronomical Unit: mean distance between earth and sun (149597870.7 km)
    LD:     Lunar distance: Mean distance between earth and the moon (~0.00257 AU)
    

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.