Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydrogen issue in Core Collapse Supernovae   We discuss results of analyzing a time series of selected
photospheric-optical spectra of core collapse supernovae (CCSNe). This is
accomplished by means of the parameterized supernovae synthetic spectrum (SSp)
code
  ``SYNOW''.
  Special attention is addressed to traces of hydrogen at early phases,
especially for the stripped-envelope SNe (i.e. SNe Ib-c). A thin low mass
hydrogen layer extending to very high ejection velocities above the helium
shell, is found to be the most likely scenario for Type Ib SNe.

17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph