| | |
| Discovery | |
|---|---|
| Discovered by | Timothy B. Spahr |
| Discovery date | November 16, 1998 |
| 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] |
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]
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.