Advancing Exoplanet Research with MARCOT: Innovative Photonic Lantern Integration for Enhanced Spectroscopic Capabilities

The MARCOT-Pathfinder Telescope (MPT), situated at the Calar Alto Observatory (CAHA) in Spain, represents the integration of a state-of-the-art Multi-Mode Photonic Lantern for usage with high-resolution spectrographs, enhancing the MARCOT-Pathfinder's optical efficiency and observational capabilities. Unlike conventional systems, the MARCOT-Pathfinder employs an array of seven small Optical Tube Assemblies (OTAs), each equipped with advanced fibre positioning systems to channel stellar light into the Multi-Mode Photonic Lantern. We will present the status of the project and summary of the studies that remain to be carried out, focusing on the work carried out to connect the MPT to a a readily available low-resolution spectrograph.

 

The MPT is a demonstrator of what could represent a significant leap in astronomical instrumentation for exoplanets research. It is the first phase of the MARCOT project which aim at developing a large aperture ground-based telescope combining several modules of tens of OTAs and reducing the cost compared to a traditional design of a telescope of the same size. For this purpose, off-the-self telescopes and commercial instrumentation have been used. A feature of this telescope is that it is modular, which allows us to increase the effective aperture by adding individual modules. The project is divided into different phases, the first of which is to demonstrate the functionality of this technology with the MPT. In phase-two we want to build a telescope with a 5-m effective aperture, using individual modules. Finally, the last phase will be to use several modules of 5-m effective aperture giving a total effective aperture of 15-m. MARCOT will be installed at Calar Alto Observatory with each of its modules enclosed in its own small dome.

 

This innovative setup allows for a unique, combination of the light collected by each individual telescope, effectively emulating a larger, monolithic telescope’s light-gathering power but at a fraction of the cost and complexity. The integration significantly increases the signal-to-noise ratio, crucial for detecting exoplanets around faint stars. The driver science case will be the detection and characterization of exoplanets, to which we will dedicate most of the guaranteed time observations. Specifically, with a MARCOT telescope featuring a 5-m effective aperture, we could access over 400 exoplanets already detected by TESS and Kepler, and conduct studies of their masses and densities. Similarly, we are interested in planetary systems around ultracool dwarfs, about which little is currently known. Detecting these faint objects requires large-aperture telescopes to collect more photons and a high-resolution spectrograph to achieve precise measurements of their radial velocity variations.