2019 XS is a small Apollo near-Earth asteroid discovered on 2 December 2019 by the Mount Lemmon Survey in Arizona, United States.[2] It passed 1.493 lunar distances (574,000 km; 357,000 mi) from Earth on 9 November 2021 at 03:48 UTC, after which observations were checked by the International Asteroid Warning Network for timing and astrometric accuracy.[7][8][9] During the close pass, the asteroid trailed across the far Southern Hemisphere to the Northern Hemisphere and reached a peak apparent magnitude of 13. A total of 957 observations were collected by Minor Planet Center as part of the International Asteroid Warning Network's campaign.[10]

2019 XS
Goldstone radar images of 2019 XS taken on 11 November 2021
Discovery [1][2]
Discovered byMLS
Discovery siteMt. Lemmon Obs.
Discovery date2 December 2019
Designations
2019 XS
C1HDFQ2 [3]
NEO · Apollo[4]
Orbital characteristics[4]
Epoch 21 January 2022 (JD 2459600.5)
Uncertainty parameter 0
Observation arc21.68 yr (7,919 days)
Earliest precovery date4 April 2000
Aphelion1.332 AU
Perihelion0.6766 AU
1.005 AU
Eccentricity0.3264
1.01 yr (367.74 days)
140.339°
0° 58m 44.218s / day
Inclination4.447°
49.483°
250.285°
Earth MOID0.004003 AU (598,800 km)
Physical characteristics
Mean diameter
~70 m [5]
2.35±0.01 h[6]
3.01±0.01 h[6]
23.96±0.33[4]
23.87 [1]

2019 XS is well-observed with a long observation arc of over 21 years, enough to distinguish subtle changes in its orbit over time due non-gravitational acceleration by the Yarkovsky effect.[4][10] Highly precise radar observations by NASA's Goldstone Solar System Radar on 11 November 2021 have significantly constrained the asteroid's orbit and 2021 close approach distance to within a few kilometres.[4] Radar imaging has shown that the asteroid is roughly 70 m (230 ft) in diameter, with a rotation period around 3 hours.[5]

Continuous photometric observations by the Center for Solar System Studies in Landers, California show an irregular light curve for 2019 XS, signifying that the asteroid is in a tumbling rotation state.[6] The light curve of 2019 XS appears to display two overlapping periods of 2.35 and 3.01 hours, which could possibly be associated with the asteroid's rotation and precession.[6]

See also edit

  • 2012 TC4, another near-Earth asteroid with a dedicated IAWN timing campaign

References edit

  1. ^ a b "2019 XS". Minor Planet Center. International Astronomical Union. Retrieved 12 October 2021.
  2. ^ a b "MPEC 2019-X47 : 2019 XS". Minor Planet Electronic Circular. Minor Planet Center. 4 December 2019. Retrieved 12 October 2021.
  3. ^ "2019 XS". NEO Exchange. Las Cumbres Observatory. 5 October 2021. Retrieved 12 October 2021.
  4. ^ a b c d e "JPL Small-Body Database Browser: (2019 XS)" (2021-12-09 last obs.). Jet Propulsion Laboratory. Retrieved 7 January 2022.
  5. ^ a b Benner, Lance A. M. "Goldstone Radar Observations Planning: Orpheus, 2004 UE, 2019 XS, and 2010 VK139". Jet Propulsion Laboratory. California Institute of Technology. Retrieved 12 November 2021.
  6. ^ a b c d Warner, Brian D.; Stephens, Robert D. (April 2022). "Near-Earth Asteroid Lightcurve Analysis at the Center for Solar System Studies: 2021 October-December". The Minor Planet Bulletin. 49 (2): 83–89. Bibcode:2022MPBu...49...83W.
  7. ^ "2019 XS: Timing Assessment". International Asteroid Warning Network. 3 October 2021. Retrieved 12 October 2021.
  8. ^ "MPEC 2021-T79 : International Asteroid Warning Network (IAWN) Timing Campaign". Minor Planet Electronic Circular. Minor Planet Center. 5 October 2021. Retrieved 12 October 2021.
  9. ^ "MPEC 2020-V63 : 2019 XS". Minor Planet Electronic Circular. Minor Planet Center. 10 November 2020. Retrieved 12 October 2021.
  10. ^ a b Farnocchia, Davide; Reddy, Vishnu; Bauer, James M.; Warner, Elizabeth M.; Micheli, Marco; Payne, Matthew J.; et al. (July 2022). "International Asteroid Warning Network Timing Campaign: 2019 XS". The Planetary Science Journal. 3 (7): 13. Bibcode:2022PSJ.....3..156F. doi:10.3847/PSJ/ac7224. hdl:10045/125567. 156.

External links edit