(248370) 2005 QN173

(248370) 2005 QN173
Cerro Tololo Observatory image of 2005 QN173 with a long, narrow tail (indicated with white arrows) on 22 July 2016
Discovery[1]
Discovered byNEAT
Discovery sitePalomar Observatory
Discovery date29 August 2005
Designations
433P/(248370) 2005 QN173
2005 QN173
main-belt · (outer)[2]
Orbital characteristics[2]
Epoch 25 February 2023 (JD 2460000.5)
Uncertainty parameter 0
Observation arc22.05 yr (8,055 days)
Aphelion3.755 AU
Perihelion2.374 AU
3.064
Eccentricity0.2254
5.36 yr (1,959 d)
119.934°
0° 11m 1.494s / day
Inclination0.068°
174.334°
145.860°
Physical characteristics[2]
3.599±0.214 km
0.054
C[3]
15.53[2]

(248370) 2005 QN173 is a main belt asteroid that undergoes recurrent comet-like activity near perihelion,[4][5] and is now designated comet 433P/(248370) 2005 QN173.[6] This object was discovered on 29 August 2005 by the Near-Earth Asteroid Tracking program at Palomar Observatory.[1] It orbits in the outer main asteroid belt[7] with an orbital period of 5.36 years, a semi-major axis of 3.06 AU, and an orbital eccentricity of 0.225, bringing it as close as 2.37 AU to the Sun at perihelion. The orbital plane is inclined at an angle of 0.068° to the ecliptic.[2]

On 7 July 2021, 2005 QN173 was found to be active by the Asteroid Terrestrial-impact Last Alert System survey.[6] Archival imagery showed it had been active during a previous perihelion passage,[8] dated 22 July 2016.[9] This indicates the activity is due to the sublimation of icy volatiles,[6] as is common with comets.[9] At the time that activity was identified, the object displayed a long, dusty tail, much like a comet. Follow up observations found this tail extended more than 9′ along its orbital plane.[7] By 14 August 2021, the coma around the nucleus was fading, while the brightness of the tail remained roughly constant.[6]

This asteroid has a mean diameter of 3.6±0.2 km, with a low visual albedo of 0.054±0.012. Its colors are consistent with a dark C-type carbonaceous asteroid taxonomic classification, which is a class more commonly found in the outer main belt. Dust particles ejected from the object had very low velocities of about 1 m/s. This suggests that the dust emission may have been assisted by rapid spin of the asteroid, which would lower the escape velocity.[3]

The asteroid will make its next perihelion passage on 3 September 2026, and it may become active by February 2026.[3]

  1. ^ a b Cite error: The named reference MPC-object was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference jpldata was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Hsieh_et_al_2021b was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference PSI_2021 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Jefferson_2021 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Lister_et_al_2022 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Hseih_et_al_2021a was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Chandler_et_al_2021a was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Chandler_et_al_2021b was invoked but never defined (see the help page).