Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First detection of a disk free of volatile elements around a young
  A-type star: A sign of collisions between rocky planets?   Aims. We present the first detailed analysis of the astrophysical parameters
of the poorly studied Sco-Cen member HD 152384 and its circumstellar
environment. Methods. We analyze newly obtained optical-near-IR XSHOOTER
spectra, as well as archival TESS data, of HD 152384. In addition, we use
literature photometric data to construct a detailed spectral energy
distribution (SED) of the star. Results. The photospheric absorption lines in
the spectrum of HD 152384 are characteristic of a A0 V star, for which we
derive a stellar mass of 2.1 +/- 0.1 M_sun and a stellar age > 4.5 Myr.
Superimposed on the photospheric absorption, the optical spectrum also displays
double-peaked emission lines of Ca II, Fe I, Mg I and Si I, typical of
circumstellar disks. Notably, all Hydrogen and Helium lines appear strictly in
absorption. A toy model shows that the observed emission line profiles can be
reproduced by emission from a compact (radius < 0.3 au) disk seen at an
inclination of ~24 degrees. Further evidence for the presence of circumstellar
material comes from the detection of a moderate infrared excess in the SED,
similar to those found in extreme debris disk systems. Conclusions. We conclude
that HD 152384 is surrounded by a tenuous circumstellar disk which, although
rich in refractory elements, is highly depleted of volatile elements. To the
best of our knowledge such a disk is unique within the group of young stars.
However, it is reminiscent of the disks seen in some white dwarfs, which have
been attributed to the disruption of rocky planets. We suggest that the disk
around HD 152384 may have a similar origin and may be due to collisions in a
newly formed planetary system.

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The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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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: chem-ph
3
The categories of this paper are: physics
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
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The categories of this paper are: q-bio