MARCOT Pathfinder at Calar Alto Progress Report

TL;DR

MARCOT Pathfinder at Calar Alto is a progress report on a modular telescope array concept using innovative photonic lanterns to feed a spectrograph, aiming for cost-effective large light-collecting areas.

Contribution

This paper introduces the MARCOT project and its Pathfinder, demonstrating a novel modular telescope array with Multi-Mode Photonic Lanterns for efficient light combination.

Findings

Validation of MM-PL concept on sky with prototype telescopes

Feasibility of cost-effective large-area light collection

Progress in integrating the Potsdam MRS spectrograph

Abstract

MARCOT Pathfinder is a precursor for MARCOT (Multi Array of Combined Telescopes) at Calar Alto Observatory (CAHA) in Spain. MARCOT is intended to provide CARMENES, currently fiber-fed from the CAHA 3.5m Telescope, with a 5-15m light collecting area from a battery of several tens of small telescopes that are incoherently fed into the final joint single fiber feed of the spectrograph. The modular concept, based on commercially available telescopes, results in cost estimates that are a fraction of the ones for extremely large telescopes (ELT). As a novel approach, MARCOT will employ Multi-Mode Photonic Lanterns (MM-PL) that are being developed as a variant of classical photonic lanterns, to combine the light from the individual telescopes to a single fiber feed to the instrument. This progress report presents the overall concept of MARCOT, the pathfinder telescope and enclosure that is being commissioned at CAHA, the concept of MM-PL, and the next step of installing the Potsdam Multiplex Raman Spectrograph (MRS). MARCOT Pathfinder will be used to validate the conceptual design and predicted performance of MM-PL on sky with a 7 unit telescope prototype.