PHYSICAL CHARACTERIZATION OF ∼2m DIAMETER NEAR-EARTH ASTEROID 2015 TC25: A POSSIBLE BOULDER FROM E-TYPE ASTEROID (44) NYSA

被引：19

作者：

Reddy, Vishnu ^{[1
,2
]}

Sanchez, Juan A. ^{[2
,3
]}

Bottke, William F. ^{[4
]}

Thirouin, Audrey ^{[5
]}

Rivera-Valentin, Edgard G. ^{[6
]}

Kelley, Michael S. ^{[2
,7
,8
]}

Ryan, William ^{[9
]}

Cloutis, Edward A. ^{[10
]}

Tegler, Stephen C. ^{[11
]}

Ryan, Eileen V. ^{[9
]}

Taylor, Patrick A. ^{[6
]}

Richardson, James E. ^{[3
]}

Moskovitz, Nicholas ^{[2
,5
]}

Le Corre, Lucille ^{[2
,3
]}

机构：

[1] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA

[2] Univ Hawaii, Infrared Telescope Facil, Honolulu, HI 96822 USA

[3] Planetary Sci Inst, Tucson, AZ 85742 USA

[4] Southwest Res Inst, Boulder, CO 80302 USA

[5] Lowell Observ, Flagstaff, AZ 86001 USA

[6] Arecibo Observ, Arecibo, PR 00612 USA

[7] Georgia Southern Univ, Dept Geol & Geog, Statesboro, GA 30460 USA

[8] NASA Headquarters, Planetary Sci Div, Sci Mission Directorate, Washington, DC 20546 USA

[9] Magdalena Ridge Observ New Mexico Tech, Socorro, NM 87801 USA

[10] Univ Winnipeg, Dept Geog, Winnipeg, MB R3B 2E9, Canada

[11] No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA

来源：

ASTRONOMICAL JOURNAL | 2016年 / 152卷 / 06期

基金：

美国国家航空航天局; 加拿大创新基金会; 加拿大自然科学与工程研究理事会;

关键词：

meteorites; meteors; meteoroids; minor planets; asteroids:; general; techniques: spectroscopic; 2867; STEINS; HUNGARIA; ALBEDO; ORIGIN; TARGET; SPEX;

D O I：

10.3847/0004-6256/152/6/162

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Small near-Earth asteroids (NEAs) (< 20 m) are interesting, because they are progenitors for meteorites in our terrestrial collection. The physical characteristics of these small NEAs are crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors. In the past, the characterization of small NEAs has been a challenge, because of the difficulty in detecting them prior to close Earth flyby. In this study, we physically characterized the 2 m diameter NEA 2015 TC25 using ground-based optical, near-infrared and radar assets during a close flyby of the Earth (distance 128,000 km) in 2015 October 12. Our observations suggest that its surface composition is similar to aubrites, a rare class of high-albedo differentiated meteorites. Aubrites make up only 0.14% of all known meteorites in our terrestrial meteorite collection. 2015 TC25 is also a very fast rotator with a period of 133 +/- 6 s. We combined the spectral and dynamical properties of 2015 TC25 and found the best candidate source body in the inner main belt to be the 70 km diameter E-type asteroid (44) Nysa. We attribute the difference in spectral slope between the two objects to the lack of regolith on the surface of 2015 TC25. Using the albedo of E-type asteroids (50%-60%) we refine the diameter of 2015 TC25 to 2 m, making it one of the smallest NEAs ever to be characterized.

引用

页数：7