The last two decades have seen the installation of a large number of small robotic telescopes all over the world. Unlike their bigger counterparts, these telescopes usually do not get much attention, however these facilities have allowed astronomers to gather an enormous amount of data of extraordinary importance for many fields of astrophysics. The advancement of technology has enabled remotely-controlled and/or autonomous observatories that can be easily placed at previously developed sites with good infrastructure or at remote or harsh sites with outstanding observing conditions (e.g. the High Elevation Antarctic Terahertz (HEAT) Telescope at an altitude of 4,053 m). For most of the time, robotic telescopes operate without direct human intervention, which reduces the infrastructure requirements to a minimum, compared to a classical observatory. Another cost-saving factor is the "mass-production" of complete telescope systems that can then be distributed around the world or placed in several clusters of telescopes, each sharing the same local resources.
Scientifically, robotic telescopes have become the backbones of many sky surveys studying variability and transient phenomena, or discovering asteroids or supernovae, to name just a few objectives. These kinds of surveys can obtain a full coverage of equatorial longitudes and of both hemispheres to ensure continuous and full night sky access; the prime example of such a robotic network of telescopes is the Las Cumbres Observatory (LCO), presently operating twenty-five telescopes at seven sites around the world, all working as a single unit. While most of the worldwide robotic telescopes were manufactured for this purpose, a considerable fraction has been created by transforming existing telescopes (e.g. the Palomar 48-inch Schmidt telescope which became operational in 1936 was turned into the Zwicky Transient Facility (ZTF) in 2017).
From the very beginning, it was realized that robotic and remotely-controlled telescopes have a large potential for scientific education and educational outreach. Many telescope networks and facilities have been established that are primarily used by amateur astronomers, citizen scientists, teachers, and students. This remote access allows a hands-on experience which cannot be obtained in densely populated regions plagued by light pollution. The data taken by such educational or amateur projects is often valuable for professional astronomers as well.
Given the dramatic development of robotic telescopes and their importance for present-day astrophysics, this subject represents a timely Research Topic. This holds in particular since - due to the Covid-induced pandemic - related workshops and meetings have not been held recently. Thus, the goal of this Research Topic is to provide comprehensive and up-to-date information and insights on robotic telescopes.
Authors are welcomed to submit Original Research or Review articles on the subjects listed below. Of course, any topic which is beyond that scope, but nevertheless relevant, may be suggested as well.
I) history and advancement of robotic telescopes
II) technological foundations (detectors, drives, time-keeping, enclosures, networking, databases, lower-level software)
III) advanced operations (high-level observatory operation, scheduling, calibration, data processing)
IV) heterogeneous data harvesting and cross-calibration
V) data access strategies
VI) alert response capabilities
VII) telescope networking (homogenous, heterogeneous)
VIII) site selection and maintenance strategies
IX) scientific results and highlights
X) education, public outreach
XI) future prospects
This Research Topic has been realized in collaboration with Prof. Wolfgang Osten.