171P/Spahr

171P/Spahr is a periodic comet in the Solar System. 171P/Spahr was recovered on 20–24 October 2011 at apparent magnitude 20.6 using the 2.0-metre (79 in) Faulkes Telescope South.^[3] 171P/Spahr is peaked at about magnitude 18 in 2012.^[4]

171P/Spahr

Discovery
Discovered by	Timothy B. Spahr
Discovery date	November 16, 1998
Designations
Alternative designations	P/1998 W1 P/2005 R3
Orbital characteristics
Epoch	2012-Feb-03 (JD 2455960.5)
Aphelion	5.342 AU
Perihelion	1.764 AU
Semi-major axis	3.553 AU
Eccentricity	0.5033
Orbital period	6.70 a
Inclination	21.94°
Last perihelion	January 13, 2019[1] April 30, 2012[1] September 3, 2005
Next perihelion	2025-Sep-25[2]

During the 1999 passage, the comet brightened to about magnitude 13.5.^[5]

At perihelion on January 13, 2019, when the comet was 1AU from Earth, the 3-sigma uncertainty in the comet's Earth distance was ±500 km.