171P/Spahr
 Comet 171P/Spahr as seen from the Zwicky Transient Facility (ZTF) on 24 January 2019 | |
| Discovery[1] | |
|---|---|
| Discovered by | Timothy B. Spahr |
| Discovery date | 16 November 1998 |
| Designations | |
| P/1998 W1, P/2005 R3 | |
| Orbital characteristics[2][3] | |
| Epoch | 21 November 2025 (JD 2461000.5) |
| Earliest precovery date | 13 November 1998 |
| Number of observations | 997 |
| 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 | 25 September 2025 |
| Next perihelion | 3 June 2032[4] |
| Physical characteristics | |
Mean radius | 1.25 km (0.78 mi)[5] |
| Comet total magnitude (M1) | 11.6 |
| Comet nuclear magnitude (M2) | 16.8 |
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.[6] 171P/Spahr is peaked at about magnitude 18 in 2012.[7]
During the 1999 passage, the comet brightened to about magnitude 13.5.[8]
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.
References
- ↑ T. B. Spahr (17 November 1998). D. W. Green (ed.). "Comet 1998 W1". IAU Circular. 7052 (1). Bibcode:1998IAUC.7052....1S.
- ↑ "171P/Spahr – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 12 August 2026.
- ↑ "171P/Spahr Orbit". Minor Planet Center. Retrieved 25 February 2019.
- ↑ "Horizons Batch for 171P/Spahr (90001118) on 2032-Jun-03" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 16 April 2026. (JPL#K254/9 Soln.date: 2026-Mar-07)
- ↑ M. L. Paradowski (2022). "A New Indirect Method of Determining Density of Cometary Nuclei" (PDF). Acta Astronomica. 72 (2): 141–159. Bibcode:2022AcA....72..141P. doi:10.32023/0001-5237/72.2.4. ISSN 0001-5237.
- ↑ Ernesto Guido; Giovanni Sostero; Nick Howes & Antoni Kasprzyk (28 October 2011). "Recovery of comet 171P/Spahr". Remanzacco Observatory in Italy – Comets & Neo. Retrieved 1 November 2011.
- ↑ Seiichi Yoshida (30 October 2011). "171P/Spahr". Seiichi Yoshida's Comet Catalog. Retrieved 1 March 2010.
- ↑ Kronk, Gary W. (2001–2005). "171P/Spahr". Archived from the original on 5 April 2001. Retrieved 27 February 2012.
External links
- 171P/Spahr at the JPL Small-Body Database
- 171P/Spahr at Gary W. Kronk's Cometography
- 171P/Spahr at Seiichi Yoshida's website
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