Methods: Stealth CMEs represent a particular class of solar eruptions that
are clearly distinguished in coronagraph observations, but they don't have a
clear source signature. A particular type of stealth CMEs occurs in the
trailing current sheet of a previous ejection, therefore, we used the 2.5D MHD
package of the code MPI-AMRVAC to numerically simulate consecutive CMEs by
imposing shearing motions onto the inner boundary. The initial magnetic
configuration consists of a triple arcade structure embedded into a bimodal
solar wind, and the sheared polarity inversion line is found in the southern
loop system. The mesh was continuously adapted through a refinement method that
applies to current carrying structures. We then compared the obtained eruptions
with the observed directions of propagation of an initial multiple coronal mass
ejection (MCME) event that occurred in September 2009. We further analysed the
simulated ejections by tracking the centre of their flux ropes in latitude and
their total speed. Radial Poynting flux computation was employed as well to
follow the evolution of electromagnetic energy introduced into the system.
Results: Changes within 1\% in the shearing speed result in three different
scenarios for the second CME, although the preceding eruption seems
insusceptible to such small variations. Depending on the applied shearing
speed, we thus obtain a failed eruption, a stealth, or a CME driven by the
imposed shear, as the second ejection. The dynamics of all eruptions are
compared with the observed directions of propagation of an MCME event and a
good correlation is achieved. The Poynting flux analysis reveals the temporal
variation of the important steps of eruptions. For the first time, a stealth
CME is simulated in the aftermath of a first eruption, through changes in the
applied shearing speed.Comment: 11 pages, 12 figures, to be published in "Astronomy & Astrophysics",
and the associated movies will also be available on the journal's websit
