Techniques d'observation spectroscopique d'astéroïdes

CHAPTER 6. SPECTRAL PROPERTIES OF NEAR-EARTH ASTEROIDS 103
MH-FPF-050-B) - Fig. 6.4c.
Modeling the spectra with the exponential continuum [Brunetto et al., 2006], the parameter
C s is found to be of -0.377 µm, which characterizes a surface affected by space weathering
effects. Removing this continuum and comparing with Relab meteorite spectra, the best fit
are also the ordinary chondrites, the same petrologic class but with a high content of Fe (OC
types H5, H6). The closest match in this case is a sample from a Nanjemoy meteorite, an H6
Olivine-Bronzite OC, which consists of 18% Fayalitic material (Fig. 6.4d).
1.1
1.05
2010 TD54
1.1
Taxonomic classification for 2010 TD54
tel-00785991, version 1 - 7 Feb 2013
Relative Reflectance
(a)
Relative Reflectance
1
0.95
0.9
0.85
0.8
0.75
0.17
0.16
0.15
0.14
0.13
0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4
Wavelength [um]
Relative Reflectance
(b)
Relative Reflectance
1
0.9
0.8
0.7
0.6
0.19
0.18
0.17
0.16
0.15
Spectrum
Sv
Sr
S
0.5 1 1.5 2 2.5
Wavelength [um]
(c)
0.12
Asteroid
Relab sample
0.8 1 1.2 1.4 1.6 1.8 2 2.2
Wavelength [um]
(d)
0.14
Asteroid
Relab sample
0.8 1 1.2 1.4 1.6 1.8 2 2.2
Wavelength [um]
Figure 6.5: a) The NIR spectrum of 2010 TD54; b) a polynomial fit for the spectrum of 2010 TD54 compared
with the theoretical spectra of Sv, Sr and S types; c) the reflectance spectrum of 2010 TD54 and the closest match
resulting from meteorite comparison - the L4 ordinary chondrite Saratov; d) the de-reddened spectrum of 2010
TD54 and the closest match resulting from meteorite comparison - the H4 ordinary chondrite Gruneberg.
6.2.5 2010 TD54
The analysis of this object is interesting from the point of view of its size and the phenomena
that occur on the surface of small bodies during a close encounter with Earth. With an absolute
magnitude H = 28.75, 2010 TD54 was discovered by the Catalina Sky Survey in October 09,
2010. Having an Apollo orbit type, this object passed within 0.00035 AU of the Earth on 12.55