Bibcode
Popescu, M.; Vaduvescu, O.; de León, J.; Gherase, R. M.; Licandro, J.; Boacă, I. L.; Şonka, A. B.; Ashley, R. P.; Močnik, T.; Morate, D.; Predatu, M.; De Prá, M.; Fariña, C.; Stoev, H.; Díaz Alfaro, M.; Ordonez-Etxeberria, I.; López-Martínez, F.; Errmann, R.
Bibliographical reference
Astronomy and Astrophysics, Volume 627, id.A124, 21 pp.
Advertised on:
7
2019
Journal
Citations
27
Refereed citations
25
Description
Context. The population of near-Earth asteroids (NEAs) shows a large
variety of objects in terms of physical and dynamical properties. They
are subject to planetary encounters and to strong solar wind and
radiation effects. Their study is also motivated by practical reasons
regarding space exploration and long-term probability of impact with the
Earth. Aims: We aim to spectrally characterize a significant
sample of NEAs with sizes in the range of 0.25-5.5 km (categorized as
large), and search for connections between their spectral types and the
orbital parameters. Methods: Optical spectra of NEAs were
obtained using the Isaac Newton Telescope (INT) equipped with the IDS
spectrograph. These observations are analyzed using taxonomic
classification and by comparison with laboratory spectra of meteorites.
Results: A total number of 76 NEAs were observed. We spectrally
classified 44 of them as Q/S-complex, 16 as B/C-complex, eight as
V-types, and another eight belong to the remaining taxonomic classes.
Our sample contains 27 asteroids categorized as potentially hazardous
and 31 possible targets for space missions including (459872) 2014 EK24,
(436724) 2011 UW158, and (67367) 2000 LY27. The spectral data
corresponding to (276049) 2002 CE26 and (385186) 1994 AW1 shows the 0.7
μm feature which indicates the presence of hydrated minerals on their
surface. We report that Q-types have the lowest perihelia (a median
value and absolute deviation of 0.797 ± 0.244 AU) and are
systematically larger than the S-type asteroids observed in our sample.
We explain these observational evidences by thermal fatigue
fragmentation as the main process for the rejuvenation of NEA surfaces.
Conclusions: In general terms, the taxonomic distribution of our
sample is similar to the previous studies and matches the broad groups
of the inner main belt asteroids. Nevertheless, we found a wide
diversity of spectra compared to the standard taxonomic types.
All optical data from INT are only available at the CDS via anonymous
ftp to http://cdsarc.u-strasbg.fr
(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/627/A124
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