16P/Brooks

16P/Brooks
Sketch of the fragmentation of Comet Brooks 2 on 4 August 1889
Discovery
Discovered byWilliam Robert Brooks
Discovery siteGeneva, New York
Discovery date7 July 1889
Designations
P/1889 N1, P/1896 M1
  • Brooks 2
  • 1889 V, 1896 VI
  • 1903 V, 1911 I, 1925 IX
  • 1932 VIII, 1939 VII
  • 1946 IV, 1953 V
  • 1960 VI, 1974 I
  • 1980 IX, 1987 XXIV
  • 1994 XXIII
Orbital characteristics
Epoch21 November 2025 (JD 2461000.5)
Observation arc132.56 years
Number of
observations		922
Aphelion5.440 AU
Perihelion1.885 AU
Semi-major axis3.663 AU
Eccentricity0.48453
Orbital period7.009 years
Max. orbital speed
  • 40 km/s (25 mi/s)
  • (1886 Jupiter approach)
  • 26 km/s (16 mi/s)
  • (2028 perihelion)
Inclination3.009°
138.82°
Argument of
periapsis		245.38°
Mean anomaly235.96°
Last perihelion18 April 2021
Next perihelion21 April 2028
TJupiter2.863
Earth MOID0.459 AU
Jupiter MOID0.209 AU
Physical characteristics
Mean radius
1.59 km (0.99 mi)
Comet total
magnitude (M1)		12.2
Comet nuclear
magnitude (M2)		15.6

16P/Brooks, also known as Brooks 2, is a Jupiter-family comet discovered by William Robert Brooks on 7 July 1889, but failed to note any motion. He was able to confirm the discovery the next morning, having seen that the comet had moved north. On 1 August 1889, the famous comet hunter Edward Emerson Barnard discovered two fragments of the comet labeled "B" and "C" located 1 and 4.5 arc minutes away. On 2 August he found another four or five, but these were no longer visible the next day. On August 4, he observed two more objects, labeled "D" and "E". "E" disappeared by the next night and "D" was gone by the next week. Around mid-month, "B" grew large and faint, finally disappearing at the beginning of September. "C" managed to survive until mid-November 1889. The apparition ended on 13 January 1891. After the discovery apparition, the comet has always been over two magnitudes fainter.

1886

The comet's breakup is believed to have been caused by the passage of the comet within Jupiter's Roche limit around 20 July 1886, when it spent two days within the orbit of Io.

16P/Brooks 2 best-fit Jupiter approach around 1886-Jul-20
Date & time of
closest approach		 Jupiter distance
(AU)		 Sun distance
(AU)		 Velocity
wrt Jupiter
(km/s)		 Velocity
wrt Sun
(km/s)		 Reference
1886-Jul-20 22:320.001 AU (150 thousand km; 93 thousand mi; 0.39 LD)5.457 AU (816 million km; 507 million mi)41.140.1Horizons

The very close approach to Jupiter in 1886 resulted in the previous perihelion distance becoming the new aphelion distance.

Orbital Elements for 1865 + 1889
Epoch Aphelion
(AD)		 Perihelion
(QR)		 Period
186514 AU5.5 AU31 years
18895.4 AU1.95 AU7 years

On 31 December 2016 the comet passed 0.333 AU (49.8 million km) from Jupiter and on 5 July 2053 ± 3 days it will pass about 0.26 AU (39 million km) from Jupiter.

Notes

  1. ↑ Jupiter came to aphelion (farthest distance from the Sun) one month later on 1886-Aug-21 at 5.4568 AU.
  2. ↑ Io orbits 0.0028 AU (420 thousand km) from Jupiter.
  3. ↑ 16P/Brooks came to aphelion (farthest distance from the Sun) around 1870 at ≈14.3 AU.

References

  1. ↑ "Periodic Comet Names and Designations". Planetary Data System: Small Body Node. NASA. Retrieved 17 August 2026.
  2. 1 2 3 "16P/Brooks – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 19 July 2023.
  3. ↑ "16P/Brooks Orbit". Minor Planet Center. Retrieved 16 June 2014.
  4. 1 2 "Horizons Batch for 16P/Brooks 2 (90000274) on 2028-Apr-21" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Archived from the original on 15 June 2022. Retrieved 15 June 2022. (JPL#K212/6 Soln.date: 2022-Feb-04)
  5. ↑ G. Tancredi; J. A. Fernández; H. Rickman; J. Licandro (2006). "Nuclear magnitudes and the size distribution of Jupiter family comets". Icarus. 182 (2): 527–549. Bibcode:2006Icar..182..527T. doi:10.1016/j.icarus.2006.01.007.
  6. 1 2 "Horizons Batch for 16P/Brooks 2 (90000259) on 1886-Jul-20" (1889–1904 dataset). JPL Horizons. Archived from the original on 20 July 2023. Retrieved 19 July 2023.
  7. ↑ Kinoshita, Kazuo (1 August 2016). "16P/Brooks past, present and future orbital elements". Comet Orbit. Archived from the original on 10 July 2011. Retrieved 19 July 2023.
  8. ↑ Horizons output. "Osculating Orbital Elements for 16P/Brooks (90000258)". Retrieved 20 July 2023.