(16960) 1998 QS52

(16960) 1998 QS₅₂

Discovery[1]
Discovered by	LINEAR
Discovery site	Lincoln Lab's ETS
Discovery date	25 August 1998
Designations
MPC designation	(16960) 1998 QS52
Alternative designations	1998 QS52
Minor planet category	Apollo · NEO · PHA[1][2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	34.36 yr (12,551 days)
Aphelion	4.0928 AU
Perihelion	0.3133 AU
Semi-major axis	2.2030 AU
Eccentricity	0.8578
Orbital period (sidereal)	3.27 yr (1,194 days)
Mean anomaly	244.09°
Mean motion	0° 18^m 5.04^s / day
Inclination	17.546°
Longitude of ascending node	260.48°
Argument of perihelion	242.95°
Earth MOID	0.0144 AU (5.6 LD)
Physical characteristics
Mean diameter	4.10 km (calculated)[3]
Synodic rotation period	2.900±0.001 h (alternative)[4][a] 5.789±0.001 h[3] 5.8±0.1 h[5]
Geometric albedo	0.20 (assumed)[3]
Spectral type	SMASS = Sq[1] · Sr[6]
Absolute magnitude (H)	14.3[1][3] · 14.79±0.23[7]

(16960) 1998 QS₅₂ (provisional designation 1998 QS₅₂) is a stony asteroid on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 4.1 kilometers (2.5 mi) in diameter. It was discovered on 25 August 1998, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States.^[2] This asteroid is one of the largest potentially hazardous asteroid known to exist.^[8]

Orbit and classification

1998 QS₅₂ is a member of the dynamical Apollo group,^[1][2] which are Earth-crossing asteroids. Apollo asteroids are the largest subgroup of near-Earth objects. It orbits the Sun at a distance of 0.31–4.1 AU once every 3 years and 3 months (1,194 days; semi-major axis of 2.20 AU). Its orbit has an exceptionally high eccentricity of 0.86 and an inclination of 18° with respect to the ecliptic.^[1]

The body's observation arc begins with a precovery taken at the Siding Spring Observatory in June 1983, more than 15 years prior to its official discovery observation at Socorro.^[2]

Close approaches

With an absolute magnitude of 14.3, 1998 QS₅₂ is one of the brightest and largest known potentially hazardous asteroid (see PHA-list).^[8] It has an Earth minimum orbital intersection distance of 0.0144 AU (2,150,000 km), which corresponds to 5.6 lunar distances.^[1] Its eccentric orbit leads to close approaches with Mercury and Venus and carries it beyond the asteroid belt but not as far as to the orbit of Jupiter (>4.9 AU). It is therefore also a Venus- and Mars-crossing asteroid.^[1]

Physical characteristics

In the SMASS classification, 1998 QS₅₂ is a Sq-subtype, that transitions between the stony S- and Q-type asteroids.^[1] Observers at the NASA Infrared Telescope Facility have also characterized this body as an Sr-type, which transitions to the rare R-type asteroids.^[6]

Rotation period

In 2008, two rotational lightcurves of 1998 QS₅₂ were obtained independently from photometric observations by Brian Warner at the Palmer Divide Observatory and by Brian Skiff during the Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS) . Lightcurve analysis gave a rotation period of 5.789 and 5.8 hours with a brightness amplitude of 0.24 and 1.4 magnitude, respectively (U=2/2).^[3][5] An alternative period solution of 2.9 hours – or half of the above period – is also possible, though considered less likely by Warner.^[4][a]

Diameter and albedo

1998 QS₅₂ has not been observed by any of the space-based surveys such as IRAS, Akari or the Wide-field Infrared Survey Explorer. The Collaborative Asteroid Lightcurve Link assumes a stony standard albedo of 0.20 for its surface, and calculates a diameter of 4.10 kilometers based on an absolute magnitude of 14.3.^[3]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 13 September 2000.^[9] As of 2018, it has not been named.^[2]

Notes

1. Lightcurve plot of (16960) 1998 QS₅₂: alternative period solution of 2.900±0.001 hours with a brightness amplitude of 0.24±0.02 mag. Quality Code of 2. Summary figures at the LCDB

References

1. "JPL Small-Body Database Browser: 16960 (1998 QS52)" (2017-10-24 last obs.). Jet Propulsion Laboratory. Retrieved 17 January 2018.
2. "16960 (1998 QS52)". Minor Planet Center. Retrieved 17 January 2018.
3. "LCDB Data for (16960)". Asteroid Lightcurve Database (LCDB). Retrieved 17 January 2018.
4. Warner, Brian D. (January 2009). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 May - September". The Minor Planet Bulletin. 36 (1): 7–13. Bibcode:2009MPBu...36....7W. ISSN 1052-8091. Retrieved 17 January 2018.
5. Skiff, Brian A.; Bowell, Edward; Koehn, Bruce W.; Sanborn, Jason J.; McLelland, Kyle P.; Warner, Brian D. (July 2012). "Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS) - 2008 May through 2008 December". The Minor Planet Bulletin. 39 (3): 111–130. Bibcode:2012MPBu...39..111S. ISSN 1052-8091. Retrieved 17 January 2018.
6. Popescu, M.; Birlan, M.; Binzel, R.; Vernazza, P.; Barucci, A.; Nedelcu, D. A.; et al. (November 2011). "Spectral properties of eight near-Earth asteroids". Astronomy and Astrophysics. 535: 15. Bibcode:2011A&A...535A..15P. doi:10.1051/0004-6361/201117118. Retrieved 17 January 2018.
7. Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID 53493339. Retrieved 17 January 2018.
8. "List of the Potentially Hazardous Asteroids (PHAs)". Minor Planet Center. Retrieved 18 January 2018.
9. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 24 February 2018.

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• (16960) 1998 QS52 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• (16960) 1998 QS52 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• (16960) 1998 QS52 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters