[Paper Review] Astro2020 Project White Paper: PolyOculus -- Low-cost Spectroscopy for the Community

Stephen S. Eikenberry, Misty C. Bentz+7 more|arXiv (Cornell University)|Jul 18, 2019

Semiconductor Lasers and Optical Devices4 references4 citations

TL;DR

PolyOculus proposes a low-cost, scalable spectroscopy system using fiber-optic-linked small telescopes to enable large-area, automated spectroscopic follow-up of transient sources. By linking multiple commercial-off-the-shelf telescopes via fiber optics, it achieves 10x lower construction costs than traditional large telescopes while supporting remote, automated operations for time-domain surveys like LSST.

ABSTRACT

As astronomy moves into the era of large-scale time-domain surveys, we are seeing a flood of new transient and variable sources which will reach biblical proportions with the advent of LSST. A key strategic challenge for astronomy in this era is the lack of suitable spectroscopic followup facilities. In response to this need, we have developed the PolyOculus approach for producing large-area-equivalent telescopes by using fiber optics to link modules of multiple semi-autonomous, small, inexpensive, commercial-off-the-shelf telescopes. Crucially, this scalable design has construction costs which are $>10x$ lower than equivalent traditional large-area telescopes. In addition, PolyOculus is inherently highly automated and well-suited for remote operations. Development of this technology will enable the expansion of major research efforts in the LSST era to a host of smaller universities and colleges, including primarily-undergraduate institutions, for budgets consistent with their educational expenditures on similar facilities. We propose to develop and deploy a 1.6-m prototype demonstrator at the Mt. Laguna Observatory in California, followed by a full-scale 5-meter-class PolyOculus facility for linkage to existing and upcoming time-domain surveys.

Motivation & Objective

• Address the critical shortage of spectroscopic follow-up capacity for time-domain surveys in the LSST era.
• Enable smaller institutions, including primarily-undergraduate colleges, to participate in large-scale transient astronomy with affordable, scalable infrastructure.
• Develop a prototype 1.6-m demonstrator at Mt. Laguna Observatory to validate the PolyOculus concept.
• Design a full-scale 5-meter-class PolyOculus facility for integration with existing and upcoming time-domain surveys.
• Reduce construction costs by over 10x compared to traditional large-area telescopes while maintaining high automation and remote operation capability.

Proposed method

• Use fiber optics to link multiple semi-autonomous, small, commercial-off-the-shelf telescopes into a single large-aperture equivalent system.
• Implement a modular design that allows incremental scaling from prototype to full-scale deployment.
• Leverage existing commercial telescope components to minimize development costs and ensure rapid deployment.
• Integrate automated scheduling and remote operation systems to support unattended, high-cadence spectroscopic observations.
• Optimize the optical train and spectrograph configuration for high-throughput, low-resolution spectroscopy suitable for transient sources.
• Utilize a distributed control architecture to manage individual telescope modules while maintaining system-wide coherence and data integration.

Experimental results

Research questions

• RQ1 Can a network of small, low-cost telescopes linked via fiber optics achieve spectroscopic performance comparable to a single large telescope at a fraction of the cost?
• RQ2 How effectively can such a system support high-cadence, automated spectroscopic follow-up of transient and variable sources in the LSST era?
• RQ3 To what extent can this approach be adopted by smaller institutions with limited budgets for astronomical infrastructure?
• RQ4 What is the achievable throughput and spectral resolution of a PolyOculus system using off-the-shelf components and modular design principles?
• RQ5 How scalable and reliable is the system under continuous remote operation for long-duration time-domain surveys?

Key findings

• The PolyOculus design achieves construction costs more than 10 times lower than equivalent traditional large-area telescopes.
• The system enables large-area spectroscopic coverage through modular, fiber-linked small telescopes, scalable from prototype to full 5-meter-class facility.
• The prototype 1.6-m demonstrator at Mt. Laguna Observatory is planned to validate the core technical and operational concepts.
• Full-scale PolyOculus facilities are designed for seamless integration with existing and upcoming time-domain surveys such as LSST.
• The system is inherently automated and well-suited for remote operation, significantly reducing staffing and operational overhead.
• The approach opens access to major transient research programs for smaller universities and primarily-undergraduate institutions.