2009 DQ118

Last updated

2009 DQ118
Discovery [1] [a]
Discovery date27 February 2009 (Initial reported obs.)
Designations
2009 DQ118
Outer main belt
Orbital characteristics [2]
Epoch 21 November 2025 (JD 2461000.5)
Uncertainty parameter 0
Aphelion 4.7164 AU
Perihelion 2.4288 AU
3.5726 AU
Eccentricity 0.3202
6.7527 y (2466.4 d)
137.783°
0.1460° / d
Inclination 9.3931°
344.652°
252.059°
Jupiter  MOID 0.8036 AU
TJupiter 3.005
Physical characteristics
16.96 [2]

    2009 DQ118 is an unnamed active asteroid located in the outer main asteroid belt. It was initially reported on 27 February 2009 by the Spacewatch survey at Steward Observatory in Tucson, Arizona, United States. [1] Classified as a quasi-Hilda object, 2009 DQ118's orbit is strongly perturbed by its frequent close encounters with Jupiter. It exhibits comet-like activity, which was first observed in March 2016 and identified by volunteers working for the Active Asteroids project. As of 2025, it has not received a number from the Minor Planet Center. [2]

    Contents

    Orbit

    Diagram of 2009 DQ118's orbit in the outer main belt, near the orbit of Jupiter. 2009 DQ118 orbit.png
    Diagram of 2009 DQ118's orbit in the outer main belt, near the orbit of Jupiter.

    2009 DQ118 orbits the Sun at an average distance—its semi-major axis—of 3.57 astronomical units (AU), placing it in the outer main asteroid belt. Along its 6.75 year long orbit, its distance from the Sun varies between 2.43 AU at perihelion to 4.72 AU at aphelion due to its orbital eccentricity of 0.32. Its orbit is inclined by 9.39° with respect to the ecliptic plane.

    2009 DQ118 is a member of a dynamical group of objects called the quasi-Hildas. The quasi-Hildas reside near, but do not participate in, the 2:3 mean-motion resonance (MMR) with Jupiter. Unlike the Hilda asteroids, which are defined as participating in the 2:3 Jovian MMR, quasi-Hildas are dynamically unstable. [3] : 1  [4] 2009 DQ118 experiences frequent close encounters with Jupiter, often coming as close as 2–3 Jupiter Hill radii (0.68–1.02 AU) [b] to the planet. [3] : 3 

    As of 2025, its Tisserand parameter with respect to Jupiter (TJ) is 3.005, [2] just above the TJ = 3 boundary. [3] : 4  Objects with TJ < 3 are considered Jupiter-crossing comets, whereas those with TJ > 3 are considered asteroids. [3] : 3 2009 DQ118's close encounters with Jupiter significantly alter its orbit, causing it to frequently cross the TJ = 3 boundary—up to dozens of times over the course of 1,000 years. Though currently in an asteroid-like orbit, in the past it was likely a Jupiter-family comet (JFC) or a centaur. According to numerical simulations performed in 2023, it will once again become a JFC 1,000 years in the future. Thereafter, it is likely to remain a JFC or become a centaur, though there is a small chance that it will transition back to an asteroid-like orbit or even become a near-Earth object. [3] : 4 

    Activity

    2009 DQ118 exhibits comet-like activity, which was first identified by citizen science volunteers working for the Active Asteroids project. Observations taken in 8–11 March 2016, four months before 2009 DQ118's 2016 perihelion passage, showed a tail. Follow-up observations were conducted using the Apache Point Observatory's 3.5-m Astrophysical Research Consortium (ARC) telescope on 24 February 2023. At that time, 2009 DQ118 was approaching perihelion. Despite poor observing conditions, a faint tail was spotted, and further observations were carried out using Las Campanas Observatory's 6.5-m Walter Baade Magellan Telescope on 22 April, at 2009 DQ118's perihelion. The 22 April observations also showed a faint tail. [3] : 2  The timing of 2009 DQ118's periods of activity with its perihelion passages suggests that its activity is likely driven by the sublimation of volatile ices. [3] : 6  [5] : 14 

    See also

    Other active asteroids identified by the Active Asteroids project:

    Notes

    1. ↑ Discoverer not yet assigned by the MPC
    2. ↑ rH,J ≈ 0.34 AU [3] : 3 

    References

    1. 1 2 "2009 DQ118". Minor Planet Center. Retrieved 9 November 2025.{{cite web}}: CS1 maint: url-status (link) (38 obs)
    2. 1 2 3 4 "JPL Small-Body Database Lookup: (2009 DQ118)" (2022-02-09 last obs.). Jet Propulsion Laboratory . Retrieved 9 November 2025.{{cite web}}: CS1 maint: url-status (link)
    3. 1 2 3 4 5 6 7 8 Oldroyd, William J.; et al. (November 2023). "Recurring Activity Discovered on Quasi-Hilda 2009 DQ118". The Astrophysical Journal Letters. 957 (1). arXiv: 2311.02160 . Bibcode:2023ApJ...957L...1O. doi: 10.3847/2041-8213/acfcbc . L1.
    4. ↑ Toth, I. (March 2006). "The quasi-Hilda subgroup of ecliptic comets - an update". Astronomy and Astrophysics. 448 (3): 1191–1196. Bibcode:2006A&A...448.1191T. doi: 10.1051/0004-6361:20053492 .
    5. ↑ Chandler, Colin Orion; et al. (April 2024). "The Active Asteroids Citizen Science Program: Overview and First Results". The Astronomical Journal. 167 (4). arXiv: 2403.09768 . Bibcode:2024AJ....167..156C. doi: 10.3847/1538-3881/ad1de2 . 156.
    This page is based on this Wikipedia article
    Text is available under the CC BY-SA 4.0 license; additional terms may apply.
    Images, videos and audio are available under their respective licenses.