Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Episodic disk accretion in the halo of the 'old' Pre-Main Sequence
  cluster Eta Chamaeleontis   We present multi-epoch medium-resolution observations of two M4.5 candidate
members in the halo of the ~8 Myr Eta Chamaeleontis open cluster. Over six
months of observations both stars exhibited variations in their H-alpha line
profiles on timescales of days to months, with at least one episode of
substantial activity attributable to accretion from a circumstellar disk. We
derive an accretion rate ~10^-8.7 Msun/yr for this event, with a rate of
~10^-10.6 Msun/yr in quiescence. Episodic accretion like that observed here
means existing surveys of accreting Weak-lined T-Tauri Stars in young clusters
are likely incomplete and that gas dissipation timescales calculated from the
fraction of accreting objects are underestimates.

12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn