(154276) 2002 SY50, provisional designation 2002 SY50, is a stony asteroid on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 1.1 kilometers (0.7 miles) in diameter. It was discovered on 30 September 2002, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States.[1] The K-type asteroid has a rotation period of 4.8 hours.[3][a] It will make a close encounter with Earth on 30 October 2071.[6]

(154276) 2002 SY50
Discovery[1]
Discovered byLINEAR
Discovery siteLincoln Lab's ETS
Discovery date30 September 2002
Designations
(154276) 2002 SY50
2002 SY50
Apollo · NEO · PHA[1][2]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc11.78 yr (4,304 d)
Aphelion2.8793 AU
Perihelion0.5297 AU
1.7045 AU
Eccentricity0.6892
2.23 yr (813 d)
305.15°
0° 26m 34.44s / day
Inclination8.7443°
34.298°
99.395°
Earth MOID0.0027 AU (1.0519 LD)
Physical characteristics
0.897 km (calculated)[3]
1.060±0.346 km[4]
4.823 h[a]
0.143±0.173[4]
0.20 (assumed)[3]
K[5] · S (assumed)[3]
17.00[5]
17.6[2][3][4]

Orbit and classification

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2002 SY50 is a member of the Earth-crossing group of Apollo asteroids, the largest group of near-Earth objects with approximately 10 thousand known members.[1][2]

It orbits the Sun at a distance of 0.53–2.88 AU once every 2 years and 3 months (813 days; semi-major axis of 1.7 AU). Its orbit has an eccentricity of 0.69 and an inclination of 9° with respect to the ecliptic.[2] Due to its large aphelion of 2.88 AU, it also crosses the orbit of Mars at 1.66 AU.[2] The body's observation arc begins one month prior to its official discovery observation with its first observation by the NEAT program at Palomar Observatory in August 2002.[1]

Close approaches

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The asteroid has an Earth minimum orbital intersection distance of 0.0027 AU (404,000 km; 251,000 mi), which corresponds to 1.05 lunar distances and makes it a potentially hazardous asteroid due to its sufficiently large size.[2]

In November 1933, it approached Earth at a nominal distance of 0.098 AU (38 LD), and in November 2002 at 0.084 AU (33 LD). Its closest near-Earth encounter is predicted to occur on 30 October 2071, at a distance of 0.0088 AU (3.4 LD) only (see table).[6]

History of close approaches of large near-Earth objects since 1908 (A)
PHA Date Approach distance (lunar dist.) Abs.
mag

(H)
Diameter (C)
(m)
Ref (D)
Nomi-
nal(B)
Mini-
mum
Maxi-
mum
(33342) 1998 WT24 1908-12-16 3.542 3.537 3.547 17.9 556–1795 data
(458732) 2011 MD5 1918-09-17 0.911 0.909 0.913 17.9 556–1795 data
(7482) 1994 PC1 1933-01-17 2.927 2.927 2.928 16.8 749–1357 data
69230 Hermes 1937-10-30 1.926 1.926 1.927 17.5 668–2158 data
69230 Hermes 1942-04-26 1.651 1.651 1.651 17.5 668–2158 data
(137108) 1999 AN10 1946-08-07 2.432 2.429 2.435 17.9 556–1795 data
(33342) 1998 WT24 1956-12-16 3.523 3.523 3.523 17.9 556–1795 data
(163243) 2002 FB3 1961-04-12 4.903 4.900 4.906 16.4 1669–1695 data
(192642) 1999 RD32 1969-08-27 3.627 3.625 3.630 16.3 1161–3750 data
(143651) 2003 QO104 1981-05-18 2.761 2.760 2.761 16.0 1333–4306 data
2017 CH1 1992-06-05 4.691 3.391 6.037 17.9 556–1795 data
(170086) 2002 XR14 1995-06-24 4.259 4.259 4.260 18.0 531–1714 data
(33342) 1998 WT24 2001-12-16 4.859 4.859 4.859 17.9 556–1795 data
4179 Toutatis 2004-09-29 4.031 4.031 4.031 15.3 2440–2450 data
2014 JO25 2017-04-19 4.573 4.573 4.573 17.8 582–1879 data
(137108) 1999 AN10 2027-08-07 1.014 1.010 1.019 17.9 556–1795 data
(35396) 1997 XF11 2028-10-26 2.417 2.417 2.418 16.9 881–2845 data
(154276) 2002 SY50 2071-10-30 3.415 3.412 3.418 17.6 714–1406 data
(164121) 2003 YT1 2073-04-29 4.409 4.409 4.409 16.2 1167–2267 data
(385343) 2002 LV 2076-08-04 4.184 4.183 4.185 16.6 1011–3266 data
(52768) 1998 OR2 2079-04-16 4.611 4.611 4.612 15.8 1462–4721 data
(33342) 1998 WT24 2099-12-18 4.919 4.919 4.919 17.9 556–1795 data
(85182) 1991 AQ 2130-01-27 4.140 4.139 4.141 17.1 1100 data
314082 Dryope 2186-07-16 3.709 2.996 4.786 17.5 668–2158 data
(137126) 1999 CF9 2192-08-21 4.970 4.967 4.973 18.0 531–1714 data
(290772) 2005 VC 2198-05-05 1.951 1.791 2.134 17.6 638–2061 data
(A) List includes near-Earth approaches of less than 5 lunar distances (LD) of objects with H brighter than 18.
(B) Nominal geocentric distance from the Earth's center to the object's center (Earth radius≈0.017 LD).
(C) Diameter: estimated, theoretical mean-diameter based on H and albedo range between X and Y.
(D) Reference: data source from the JPL SBDB, with AU converted into LD (1 AU≈390 LD)
(E) Color codes:   unobserved at close approach   observed during close approach   upcoming approaches

Physical characteristics

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Photometry by the Sloan Digital Sky Survey has characterized 2002 SY50 as an uncommon K-type asteroid,[5] which is typically seen among members of the Eos family in the asteroid belt.[7]: 23 

Rotation period

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In October 2002, a rotational lightcurve of this asteroid was obtained from photometric observations by Italian astronomer Gianluca Masi at the Campo Catino Astronomical Observatory (468). Lightcurve analysis gave a well-defined rotation period of 4.823 hours with a brightness amplitude of 0.52 magnitude (U=3).[a]

Diameter and albedo

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According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, this asteroid measures 1.06 kilometers in diameter and its surface has an albedo of 0.14,[4] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 0.897 kilometers based on an absolute magnitude of 17.6.[3]

Numbering and naming

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This minor planet was numbered by the Minor Planet Center on 2 April 2007 (M.P.C. 59337).[8] As of 2018, it has not been named.[1]

Notes

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  1. ^ a b c Lightcurve plot of (154276) 2002 SY50 from October 2002. Rotation period 4.823 hours with a brightness amplitude of 0.52 mag. Quality code of 3. Summary figures at the LCDB.

References

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  1. ^ a b c d e f "154276 (2002 SY50)". Minor Planet Center. Retrieved 20 April 2018.
  2. ^ a b c d e f g "JPL Small-Body Database Browser: 154276 (2002 SY50)" (2014-06-07 last obs.). Jet Propulsion Laboratory. Retrieved 20 April 2018.
  3. ^ a b c d e f "LCDB Data for (154276)". Asteroid Lightcurve Database (LCDB). Retrieved 20 April 2018.
  4. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. S2CID 9341381.
  5. ^ a b c Carry, B.; Solano, E.; Eggl, S.; DeMeo, F. E. (April 2016). "Spectral properties of near-Earth and Mars-crossing asteroids using Sloan photometry". Icarus. 268: 340–354. arXiv:1601.02087. Bibcode:2016Icar..268..340C. doi:10.1016/j.icarus.2015.12.047. S2CID 119258489.
  6. ^ a b "Close-Approach Data, JPL Small-Body Database Browser: 154276 (2002 SY50)". Jet Propulsion Laboratory. Retrieved 20 April 2018.
  7. ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131. S2CID 119280014.
  8. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 20 April 2018.
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