Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physical characterization of the active asteroid (6478) Gault   We report dense lightcurve photometry, $BVR_{c}$ colors and phase - mag curve
of (6478) Gault, an active asteroid with sporadic comet-like ejection of dust.
We collected optical observations along the 2020 Jul-Nov months during which
the asteroid appear always star-like, without any form of perceptible activity.
We found complex lightcurves, with low amplitude around opposition and a bit
higher amplitude far opposition, with a mean best rotation period of $2.46_{\pm
0.02}$ h. Shape changes were observed in the phased lightcurves after
opposition, a probable indication of concavities and surface irregularities. We
suspect the existence of an Amplitude-Phase Relationship in $C$ band. The mean
colors are $B-V = +0.84_{\pm 0.04}$, $V-R_{c} = +0.43_{\pm 0.03}$ and $B-R_{c}
= +1.27_{\pm 0.02}$, compatible with an S-type asteroid, but variables with the
rotational phase index of a non-homogeneous surface composition. From our phase
- mag curve and Shevchenko's empirical photometric system, the geometric albedo
result $p_V=0.13_{\pm 0.04}$, lower than the average value of the S-class. We
estimate an absolute mag in $V$ band of about +14.9 and this, together with the
albedo value, allows to estimate a diameter of about 3-4 km, so Gault may be
smaller than previously thought.

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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: math
30
The categories of this paper are: q-alg
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The categories of this paper are: dg-ga
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The categories of this paper are: cs
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: mtrl-th