J/A+A/630/A141 Spectra of 73 asteroids (Morate+, 2019)
The last pieces of the primitive inner belt puzzle:
Klio, Chaldaea, Svea, and Chimaera.
Morate D., de Leon J., De Pra M., Licandro J., Pinilla-Alonso N.,
Campins H., Arredondo A., Carvano J.M., Lazzaro D., Cabrera-Lavers A.
<Astron. Astrophys. 630, A141 (2019)>
=2019A&A...630A.141M 2019A&A...630A.141M (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets ; Spectra, optical
Keywords: minor planets, asteroids: general - techniques: spectroscopic
Abstract:
Several primitive families in the inner region of the main asteroid
belt were identified as potential sources for two near-Earth asteroids
(NEAs), (101955) Bennu and (162173) Ryugu, targets of the
sample-return missions OSIRIS-REx and Hayabusa2, respectively. Four of
the families, located at high proper inclinations (i>10°), have
not yet been compositionally studied: Klio, Chaldaea, Chimaera, and
Svea. We want to characterize and analyze these families within the
context of our PRIMitive Asteroid Spectroscopic Survey (PRIMASS), in
order to complete the puzzle of the origins of the two NEAs.
We obtained visible spectra (0.5-0.9um) of a total of 73 asteroids
within the Klio, Chaldaea, Chimaera, and Svea collisional families,
using the instrument OSIRIS at the 10.4m Gran Telescopio Canarias. We
performed a taxonomical classification of these objects, and an
analysis of the possible presence of absorption bands related to
aqueous alterations, comparing the results with already studied
primitive families in the inner main belt.
We present here reflectance spectra for 30 asteroids in the Klio
family, 15 in Chaldaea, 20 in Chimaera, and 8 in Svea. We show that
Klio, Chaldaea, and Chimaera members have moderately red spectral
slopes, with aqueous alteration absorption bands centered around
0.7um, characteristic of the group of primitive families known as
Erigone-like. In contrast, Svea shows no 0.7um features, and neutral
and blue spectral slopes, and thus is a Polana-like family. While all
four families might be related to (162173) Ryugu, the only family
studied in this work that might be related to (101955) Bennu is Svea.
Description:
A total of 73 low-resolution visible spectra were obtained for the
asteroids in the Klio, Chaldaea, Chimaera, and Svea families (30, 15,
20, and 8 objects, respectively), using the Optical System for Imaging
and Low Resolution Integrated Spectroscopy (OSIRIS) camera
spectrograph at the 10.4m Gran Telescopio Canarias (GTC), located at
the El Roque de los Muchachos Observatory (ORM) in La Palma, Canary
Islands, Spain.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
objects.dat 41 73 Asteroid list
sp/* . 73 Individual spectra
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See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2014)
Byte-by-byte Description of file: objects.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Fam Family name
11- 16 I6 --- Ast Asteroid number
19- 41 A23 --- FileName Name of the spectrum file in subdirectory sp
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 24 E24.19 um lambda Wavelength
26- 49 E24.19 --- Reflect Normalized reflectance value
(normalized at 1 at 0.55 microns)
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Acknowledgements:
David Morate, davidmorate(at)on.br
(End) Patricia Vannier [CDS] 05-Sep-2019