(248370) 2005 QN173

Active asteroid in the outer main belt January 2025 yes #D6D6D6 (248370) 2005 QN 173 2005 QN173 DECam 2016-07-22.png Cerro Tololo Observatory image of 2005 QN 173 with a long, narrow tail (indicated with white arrows) on July 22, 2016 NEAT Palomar Observatory August 29, 2005 433P/(248370) 2005 QN 173 main-belt(outer) February 25, 2023 (JD 2460000.5) 0 8055 days years 3.755 AU Gm in 2.374 AU Gm 23 September 2026Horizons2026 3.064 AU Gm 0.2254 1959 days years 119.934° 0.1837482 ms / day 0.068° 174.334° 145.860° 3.599 0.214 km 0.054 C 15.53 (248370) 2005 QN 173 is a main belt asteroid that undergoes recurrent comet-like activity near perihelion, and is now designated comet 433P/(248370) 2005 QN 173. This object was discovered on August 29, 2005 by the Near-Earth Asteroid Tracking program at Palomar Observatory. It orbits in the outer main asteroid belt 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. On July 7, 2021, 2005 QN 173 was found to be active by the Asteroid Terrestrial-impact Last Alert System survey. Archival imagery showed it had been active during a previous perihelion passage, dated July 22, 2016. This indicates the activity is due to the sublimation of icy volatiles, as is common with comets. 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 arcminute along its orbital plane. By August 14, 2021, the coma around the nucleus was fading, while the brightness of the tail remained roughly constant. 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 taxonomic classification as a dark C-type carbonaceous asteroid, which is a class 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. The asteroid made perihelion passage on September 3, 2026. Comet-like activity was reported from June 10 onward, becoming the third time it has been observed making an active apparition. References 2022-12-17 JPL Small-Body Database Browser: 248370 (2005 QN173) https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2248370 Jet Propulsion Laboratory 2023-02-18 (248370) = 2005 QN173 https://www.minorplanetcenter.net/db_search/show_object?object_id=248370 Minor Planet Center 2023-02-18 . 1 The Nucleus and Dust Tail of Active Asteroid (248370) 2005 QN173 Hsieh Henry Chandler Colin Denneau Larry Erasmus Nicolas Fitzsimmons Alan Kelley Michael Knight Matthew Lister Tim Miles Richard Pittichova Jana Sheppard Scott Thirouin Audrey Trujillo Chad Usher Helen Bulletin of the American Astronomical Society 53 7 2021n7i110p04 October 2021 2021DPS....5311004H . Is new finding an asteroid or a comet? It's both Planetary Science Institute phys.org October 4, 2021 https://phys.org/news/2021-10-asteroid-comet.html 2023-02-18 . New Space Rock Hybrid Discovered Near Sun; Confirmed as Both Comet and Asteroid Ron Jefferson October 6, 2021 The Science Times https://www.sciencetimes.com/articles/33799/20211006/new-space-rock-hybrid-discovered-near-sun-confirmed-both-comet.htm 2023-02-19 . Physical Characterization of Main-belt Comet (248370) 2005 QN173 Hsieh Henry H. Chandler Colin O. Denneau Larry Fitzsimmons Alan Erasmus Nicolas Kelley Michael S. P. Knight Matthew M. Lister Tim A. Pittichová Jana Sheppard Scott S. Thirouin Audrey Trujillo Chadwick A. Usher Helen Gomez Edward Chatelain Joey Greenstreet Sarah Angel Tony Miles Richard Roche Paul Wooding Ben 1 The Astrophysical Journal Letters 922 1 L9 November 2021 L9 10.3847/2041-8213/ac2c62 2109.14822 2021ApJ...922L...9H free . (248370) 2005 QN_173 1 C. O. Chandler C. A. Trujillo H. H. Hsieh Central Bureau Electronic Telegrams Daniel W. E. Green 5005 July 26, 2021 http://www.cbat.eps.harvard.edu/iau/cbet/005000/CBET005005.txt 2023-02-17 . Recurrent Activity from Active Asteroid (248370) 2005 QN173: A Main-belt Comet 1 Chandler Colin Orion Trujillo Chadwick A. Hsieh Henry H. The Astrophysical Journal Letters 922 1 L8 November 2021 L8 10.3847/2041-8213/ac365b 2111.06405 2021ApJ...922L...8C free . The LCO Outbursting Objects Key Project: Overview and Year 1 Status Lister Tim Kelley Michael S. P. Holt Carrie E. Hsieh Henry H. Bannister Michele T. Verma Aayushi A. Dobson Matthew M. Knight Matthew M. Moulane Youssef Schwamb Megan E. Bodewits Dennis Bauer James Chatelain Joseph Fernández-Valenzuela Estela Gardener Daniel Gyuk Geza Hammergren Mark Huynh Ky Jehin Emmanuel Kokotanekova Rosita Lilly Eva Hui Man-To McKay Adam Opitom Cyrielle Protopapa Silvia Ridden-Harper Ryan Schambeau Charles Snodgrass Colin Stoddard-Jones Cai Usher Helen Wierzchos Kacper Yanamandra-Fisher Padma A. Ye Quanzhi Gomez Edward Greenstreet Sarah 1 The Planetary Science Journal 3 7 173 July 2022 173 10.3847/PSJ/ac7a31 2206.09028 2022PSJ.....3..173L free Horizons Batch for 248370 (2005 QN173) on 2026-Sep-23 JPL Horizons Perihelion occurs when rdot flips from negative to positive https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27433P%27&START_TIME=%272026-Sep-22%27&STOP_TIME=%272026-Sep-25%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27 2026-04-19 (JPL#28 Soln.date: 2025-Jul-01) The 2026 Reactivation of Main-belt Comet 433P/(248370) 2005 QN173 Hsieh Henry H. etal Research Notes of the AAS 10 8 id. 228 August 2026 10.3847/2515-5172/ae954a free 2026RNAAS..10..228H Further reading yes . Comet 433P = Asteroid (248370) 2005 QN173 and its tail: new images – Sept. 12 and Oct. 27 2021 Gianluca Masi October 29, 2021 The Virtual Telescope Project 2.0 https://www.virtualtelescope.eu/2021/10/29/comet-433p-asteroid-248370-2005-qn173-and-its-tail-new-images-12-sept-and-27-oct-2021/ 2023-02-19 . Comet 433P Mike Olason October 8, 2021 Sky & Telescope AAS Sky Publishing, LLC https://skyandtelescope.org/online-gallery/comet-433p/ 2023-02-19 . Dust environment of active asteroid (248370) 2005 QN173 1 Ivanova Oleksandra Luk'yanyk Igor Husárik Marek 16th Europlanet Science Congress 2022, held September 18–23, 2022 at Palacio de Congresos de Granada, Spain EPSC2022-203 September 2022 10.5194/epsc2022-203 2022EPSC...16..203I free External links 20248370 433P/(248370) 2005 QN173 at Seiichi Yoshida's website 433P at Gideon van Buitenen's website 248370 248370 ( Category:C-type asteroids (Tholen) 0433 248370 248370 20050829