P/2003 T12 (SOHO)

P/2003 T₁₂ is a periodic comet that revolves around the Sun once every 4.11 years.^[2] On January 13, 2012, it was observed by the satellite STEREO-B, and the most documented phase of P/2003 T₁₂ was observed on that date. It is theorized to be a possible fragment of comet 169P/NEAT.^[5]

P/2003 T₁₂ (SOHO)

Discovery
Discovered by	SOHO
Discovery date	10 October 2003
Designations
MPC designation	P/2003 T12 P/2012 A3
Alternative designations	SOHO-643[1] STEREO-42
Orbital characteristics[2]
Epoch	25 May 2012 (JD 2456072.5)
Observation arc	4,592 days (12.57 years)
Number of observations	491
Aphelion	4.5612 AU
Perihelion	0.5748 AU
Semi-major axis	2.568 AU
Eccentricity	0.77617
Orbital period	4.1153 years
Inclination	11.4752°
Longitude of ascending node	176.466°
Argument of periapsis	217.669°
Last perihelion	3 July 2024[3]
Next perihelion	2028
TJupiter	2.894
Earth MOID	0.1547 AU
Jupiter MOID	1.0191 AU
Physical characteristics[4]
Mean radius	<0.26 km (0.16 mi)
Comet total magnitude (M1)	19.6
Apparent magnitude	8.5 (2012 apparition)

January 12, 2012 event

During its apparition on January 12, 2012, it ventured into the highest phase angle ever observed for a comet, and the forward-scattering enhancement in brightness was marked, as large as ~8.5 mag. This has given insight into Henyey-Greenstein (HG) space-dust.^[6]