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During the last years, a number of telescopes and instruments have been dedicated to the follow-up of GRBs: recent
studies of the prompt emission (see for instance GRB080319B) and of their afterglows, evidenced a series of phenomena
that do not fit very well within the standard fireball model. In those cases, optical observations were fundamental to
distinguish among different emission mechanisms and models. In particular, simultaneous observation in various optical
filters became essential to understand the physics, and we discovered the need to have a detailed high time resolution follow up. Finally, recent observations of the polarization in GRB 090102 clearly indicate the presence of an ordered
magnetic field favoring the electromagnetic outflows models. This is, however, only one case and, in order to detail
properly the model, we need a bit of statistics. But, after the Swift launch, the average observed intensity of GRB
afterglows showed to be lower than thought before. Robotic telescopes, as demonstrated by REM, ROTSE, TAROT, etc.
(but see also the GROND set up) is clearly the winning strategy. Indeed, as we will also briefly discuss later on, the
understanding of the prompt emission mechanism depends on the observations covering the first few hundreds seconds
since the beginning of the event with high temporal resolution. To tackle these problems and track down a realistic
model, we started the conceptual design and phase A study of a 4 meter class, fast-pointing telescope (40 sec on target),
equipped with multichannel imagers, from Visible to Near Infrared (Codevisir/Pathos). In the study we explored all the
different parts of the project, from the telescope to the instrumental suite to data managing and analysis, to the dome and
site issue. Contacts with industry have been fruitful in understanding the actual feasibility of building such a complex
machine and no show stoppers have been identified, even if some critical points should be better addressed in the Phase
B study. In this paper, we present the main results of the feasibility study we performed.
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