Abstract:
The 2.34m Vainu Bappu Telescope (VBT) is a reflecting telescope that operates in two modes, prime focus and
cassegrain focus, and is equipped with two instruments. In prime focus mode, the telescope has the F-number of
f/3.25, and the High-Resolution Echelle Spectrograph (HRES) is employed through optical fiber. On the other
hand, in cassegrain focus mode, the F-number is f/13, and the OMR Spectrograph (OMRS) is mounted for low
and medium-resolution spectroscopy. Currently, the VBT faces a limitation: either the OMRS or the HRES can
be used due to the switch in the heavy secondary mirror. To overcome this, we present a novel method enabling
the OMRS to operate from prime mode alongside the HRES. The fiber setup for OMRS is optimized with a
25-lenslet + fiber-based Integral Field Unit (IFU) capable of observing both point and extended sources. The
optimized lenslet, fiber, and fore optics design is undergoing lab testing. Our approach allows seamless operation
of both spectrographs on the same night, enhancing the observational capabilities of astronomical studies with
VBT.
