259P/Garradd Explained

259P/Garradd
Discoverer:Gordon J. Garradd
Discovery Date:September 2, 2008
Designations:P/2008 R1
Epoch:26 February 2011
Aphelion:3.659 AU
Perihelion:1.796 AU
Semimajor:2.727 AU
Eccentricity:0.3415
Period:4.50 years
Inclination:15.899°
Tjup:3.217
Earth Moid:0.858 AU
M1:13.7
Last P:8 February 2022
Next P:11 August 2026
Orbit Ref:[1]

259P/Garradd is a Jupiter-family comet and active asteroid with an orbital period of 4.5 years. It was discovered in images obtained on 2 September 2008 as part of the Siding Spring Survey by Gordon J. Garradd.[2] [3]

The comet upon discovery had an apparent magnitude of 18.5 and a coma about 15 arcseconds across.[2] The comet dimmed by 1.5 magnitudes until mid November 2008. The spectrum of the comet during that period indicated a lack of gaseous emission lines and the mass loss rate was estimated to be less than 1.5 kg/s. The comet was observed in 2011-12, when it was inactive, with the observations indicating an effective radius of about 0.3 kilometers assuming a geometric albedo of 0.05.[4] [5]

The comet was observed to be active again during the 2017 perihelion, indicating that the source of activity is sublimation. The activity started to be detected when the comet was about 2 AU from the Sun, indicating that volatile ices are located deeper under the surface, as they have been probably more depleted due to the fact that it approaches closer to the Sun during perihelion than other active asteroids.[6]

The orbit of the comet is unstable within a timescale of tens of millions years. It lies near the 3:8 orbital resonanse with Jupiter. It has a Jupiter Tisserand parameter of over three, indicating that it originates from the main asteroid belt instead of the Kuiper belt.[7] It does not belong to a known asteroid family.[8]

External links

Notes and References

  1. Web site: Small-Body Database Lookup: 259P/Garradd . ssd.jpl.nasa.gov . 20 July 2023.
  2. Garradd . G. J. . Sostero . G. . Camilleri . P. . Guido . E. . Jacques . C. . Pimentel . E. . Comet C/2008 R1 (Garradd) . International Astronomical Union Circular . 1 September 2008 . 8969 . 1 . 0081-0304.
  3. Web site: MPEC 2008-R22 : COMET C/2008 R1 (GARRADD) . www.minorplanetcenter.net . 4 September 2008 . 6 September 2024.
  4. MacLennan . Eric M. . Hsieh . Henry H. . The Nucleus of Main-Belt Comet 259P/Garradd . The Astrophysical Journal . 10 October 2012 . 758 . 1 . L3 . 10.1088/2041-8205/758/1/L3. 1209.3065 .
  5. Kleyna . J. . Meech . K. J. . Hainaut . O. R. . Faint moving object detection, and the Low Signal-to-Noise recovery of Main Belt comet P/2008 R1 Garradd . Publications of the Astronomical Society of the Pacific . October 2012 . 124 . 920 . 1083–1089 . 10.1086/668253. 1209.3833 .
  6. Hsieh . Henry H. . Ishiguro . Masateru . Knight . Matthew M. . Moskovitz . Nicholas A. . Sheppard . Scott S. . Trujillo . Chadwick A. . The Reactivation of Main-belt Comet 259P/Garradd (P/2008 R1) . The Planetary Science Journal . 1 April 2021 . 2 . 2 . 62 . 10.3847/PSJ/abe59d. free . 2102.06290 .
  7. Jewitt . David . Yang . Bin . Haghighipour . Nader . Main-Belt Comet P/2008 R1 (Garradd) . The Astronomical Journal . 1 May 2009 . 137 . 5 . 4313–4321 . 10.1088/0004-6256/137/5/4313.
  8. Hsieh . Henry H. . Novaković . Bojan . Kim . Yoonyoung . Brasser . Ramon . Asteroid Family Associations of Active Asteroids . The Astronomical Journal . 1 February 2018 . 155 . 2 . 96 . 10.3847/1538-3881/aaa5a2. free . 1801.01152 .