Lightcurve Study Of V-Type Asteroids

A massive impact event on (4) Vesta is believed to have created the Vesta family of asteroids (Asphaug, 1997). The rotational characteristics of the Vesta family provide important clues about this event, including its timing, the make-up of the resulting debris, the subsequent migration of members of the family into Earth-crossing orbits, and the deposition of the Howardite-Eucrite-Diogenite meteorites on the Earth’s surface. This study conducted lightcurve measurements of ten Vp-type asteroids, drawn from an asteroid taxonomy defined by Carvano et al. (2010) and based on the Sloan Digital Sky Survey (SDSS) Moving Object Catalogue (MOC4). These measurements identified a range of asteroid rotation periods from approximately 2.5 to 9.5 hours, as well as a potential synchronous binary system, (15121) 2000 EN14. The lightcurve results were combined with those of other V/Vp-type asteroids available in LightCurve Database (LCDB; Warner et al., 2009), and matched with both WISE diameter/albedo (J. Masiero et al., 2011) and near-infrared spectroscopic (Hardersen et al., 2014-2018) data. This integrated approach identified a set of Vesta family asteroids with relatively fast spin rates, nearly spherical shapes, and loose aggregate compositions. These findings, combined with the non-Maxwellian shape of this population’s spin rate distribution, highlighted the importance of thermal Yarkovsky-YORP effects on the evolution of the Vesta family

Lightcurve Study of Vp-Type Asteroids

A massive impact event on (4) Vesta is believed to have created the Vesta family of asteroids (Asphaug, 1997). The rotational characteristics of the Vesta family provide important clues about this event, including its timing, the make‐up of the resulting debris, the subsequent migration of members of the family into Earth‐crossing orbits, and the deposition of the Howardite‐Eucrite‐Diogenite meteorites on the Earth’s surface. This study conducted lightcurve measurements of ten Vp‐type asteroids, drawn from an asteroid taxonomy defined by Carvano et al. (2010) and based on the Sloan Digital Sky Survey (SDSS) Moving Object Catalogue (MOC4). These measurements identified a range of asteroid rotation periods from approximately 2.5 to 9.5 hours, as well as a potential synchronous binary system, (15121) 2000 EN14. The lightcurve results were combined with those of other V/Vp‐type asteroids available in LightCurve Database (LCDB; Warner et al., 2009), and matched with both WISE diameter/albedo (J. Masiero et al., 2011) and near‐infrared spectroscopic (Hardersen et al., 2014‐2018) data. This integrated approach identified a set of Vesta family asteroids with relatively fast spin rates, nearly spherical shapes, and loose aggregate compositions. These findings, combined with the non‐ Maxwellian shape of this population’s spin rate distribution, highlighted the importance of thermal Yarkovsky‐YORP effects on the evolution of the Vesta family

Basalt or Not? Near-infrared Spectra, Surface Mineralogical Estimates, and Meteorite Analogs for 33 V-p-type Asteroids

Investigations of the main asteroid belt and efforts to constrain that population's physical characteristics involve the daunting task of studying hundreds of thousands of small bodies. Taxonomic systems are routinely employed to study the large-scale nature of the asteroid belt because they utilize common observational parameters, but asteroid taxonomies only define broadly observable properties and are not compositionally diagnostic. This work builds upon the results of work by Hardersen et al., which has the goal of constraining the abundance and distribution of basaltic asteroids throughout the main asteroid belt. We report on the near-infrared (NIR: 0.7 to 2.5 mu m) reflectance spectra, surface mineralogical characterizations, analysis of spectral band parameters, and meteorite analogs for 33 V-p asteroids. NIR reflectance spectroscopy is an effective remote sensing technique to detect most pyroxene group minerals, which are spectrally distinct with two very broad spectral absorptions at similar to 0.9 and similar to 1.9 mu m. Combined with the results from Hardersen et al., we identify basaltic asteroids for similar to 95% (39/41) of our inner-belt Vp sample, but only similar to 25% (2/8) of the outer-belt Vp sample. Inner-belt basaltic asteroids are most likely associated with (4) Vesta and represent impact fragments ejected from previous collisions. Outer-belt V-p asteroids exhibit disparate spectral, mineralogical, and meteorite analog characteristics and likely originate from diverse parent bodies. The discovery of two additional likely basaltic asteroids provides additional evidence for an outer-belt basaltic asteroid population.NASA Planetary Astronomy Program Grant [NNX14AJ37G]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]