KEYWORDS: Astronomy, Photometry, Spectroscopy, Databases, Astrophysics, Data archive systems, Astrometry, Astronomical software, Open source software, Data transmission, Data storage
Introducing HERMES (HOP Enabled Rapid Message Exchange Service), an application which supports sharing and querying structured data containing targets, photometry, spectroscopy, astrometry, and more. Many branches of astronomy, particularly time-domain and multimessenger astrophysics, are driven by time-critical alerts. Coordinating the community-wide response to provide characterization observations of the alerts is critical to realizing many of the science goals in these fields. As part of the SCIMMA (Scalable CyberInfrastructure to support multimessenger astrophysics) project, HERMES provides a platform for users to share messages and data in a structured format that can be sent over the SCIMMA Kafka streams, while also delivering a queryable database of those messages. The goal of HERMES is to encourage more astronomers to share data in a common, machine-readable format. While the platform is robust and general enough to handle many kinds of astrophysical data, HERMES is especially useful for non-localized event follow-up such as gravitational wave or neutrino events and maintains relationships between non-localized events and related messages and targets of interest. We discuss the Domain-Specific Language (DSL) designed for sharing structured astronomical data through HERMES, which also supports formatting and submitting data to external services such as NASA’s GCN (General Coordinates Network) circulars or the TNS (Transient Name Server). Finally, we present the integration between HERMES and TOM (Target and Observation Management) Toolkit based systems, allowing TOM users to share or ingest data through HERMES.
Introducing the open-source Observatory Control System (OCS) project, which aims to provide a suite of software for managing the user-facing operations of an observatory. It includes applications for managing users and proposals, requesting and scheduling observations, and storing and accessing data products. The OCS applications are fully API-driven for core functionality, and consist of a Python Django backend with VueJS frontend (where applicable) and a set of accompanying Python libraries. Using the OCS, observatories can enjoy seamless integration with the Astronomical Event Observatory Network (AEON) initiative. The core of the project consists of the Observation Portal, which provides user account and observational request life-cycle management, and the Configuration Database, which defines the capabilities of telescopes and instruments at the observatory. The OCS provides a fully functional adaptive scheduler and science archive, while its modular architecture allows them to be substituted for solutions specific to a given observatory. A flexible observation request language is employed which is suitable for a wide-range of telescope and instrument types. The OCS project applications are currently in use at Las Cumbres Observatory (LCOGT), managing a network of 25 telescopes, thousands of users and their proposals, and millions of observations.
Las Cumbres Observatory global telescope (LCOGT) is a unique worldwide network of dynamically scheduled, fully robotic optical telescopes, purpose built for time domain astronomy. The LCOGT network enters its second decade of operations in 2024. A flood of transient alerts are expected from the Vera C. Rubin Legacy Survey of Space and Time (LSST) and multimessenger observatories. In 2023 LCOGT will complete the northern hemisphere 1-m telescope ring, currently four telescopes at McDonald and Teide Observatories, with the addition of two 1-m telescopes at Ali Observatory in Tibet. The southern ring is complete at the Siding Spring, Cerro Tololo and the South African Astronomical Observatories. LCOGT is an active partner in the Astrophysical Event Observatory Network (AEON) with NOIRLab facilities (Gemini Observatory, SOAR Observatory, and the Community Science and Data Center), to develop the infrastructure to efficiently carry out astronomical observations in the Vera C. Rubin Observatory LSST era. While the global pandemic has provided multiple operational challenges, hardware and software projects currently underway will make LCOGT an even more powerful transient follow-up facility in its second decade of operations.
Las Cumbres Observatory comprises 25 robotic telescopes hosting 6 instrument types at 7 sites. To manage the calibrations for such a large suite of instruments, LCO has developed a Target and Observation Manager (TOM) built on elements of the TOM Toolkit. In the Calibration-TOM, the fundamental assets to be managed are not astronomical targets (as with a TOM built for a science campaign) but the telescopes and instruments of the observatory. The Calibration-TOM is a web application that uses python code within a Django framework. Requests for recurring, nighttime calibrations are described by dynamic cadences, which are inserted into each instrument’s schedule with specified durations. In 2021, we began using the Calibration-TOM for observations of flux and RV standards for the NRES spectrographs, as well as for observations of photometric standards for all imagers. The Calibration-TOM makes the scheduling and outcomes of calibrations more transparent to operations personnel, expediting the identification of underperforming instruments. Other observatories supporting multiple instruments may benefit from creating similar TOM software.
We present ExoTOM – a target-observation-manager automating exoplanet transit follow-up. ExoTOM is built upon the TOM-toolkit developed by Las Cumbres Observatory (LCO). ExoTOM keeps track of known transiting exoplanet targets (and candidates), automatically predicts their transit times and observability at several telescope sites, and plans and requests observations via the LCO observing portal API. Target selection can be constrained by magnitude, transit depth and manually set priorities. The recorded photometric data is then automatically retrieved and analyzed. A simple transit fit is performed using the batman transit modeling package. The data and analysis products can be accessed and edited via the ExoTOM web interface. An analysis procedure was developed to extract the cleanest possible transit light curves from the photometric data. The main challenge was to find the best radius for the aperture photometry and the best sample of reference stars to use for the differential photometry. The analysis procedure first removes outlier reference stars and frames and then uses a new algorithm to solve the discrete optimization problem of selecting the best reference stars and aperture. From January through September 2021, ExoTOM’s automatic observation scheduling produced 18 whole transit observations and 14 more of just the ingress or egress. The targets were TESS objects of interest ranging from TESS magnitude 8.7 to 13.5 mag and transit depth 1.5 to 118 mmag. These observations were done on the 50cm Cassegrain telescope of the Institute of Astrophysics of the University of Göttingen.
Astrophysical phenomena occur on a range of timescales, and to properly characterize them, observations must be made at appropriate intervals on instrumentation determined by the scientific goals of the study. The traditional model of scheduling telescope time in blocks of consecutive nights and requiring the investigators to operate the instrument (either in person or remotely) is not optimal for this science. A queue-scheduled approach to time allocation can relieve the personal and financial burden of interactive observing runs. This is particularly powerful when requests for observations can be made through a programmatic interface, which provides not just a convenient tool for all astronomy programs, but also the opportunity to build fully automated observing programs. This will be an essential component of projects making follow-up observations for modern surveys that produce millions of alerts per night, as much of the science return will depend upon obtaining classification and characterization data rapidly and efficiently, as well as for coordination of observations across multiple facilities. The AEON Network is an initiative to build a programmatically accessible, queue-scheduled and user driven network of telescopes ideal for modern astronomical observing programs.
One aspect of the SALT X-ray transient program is the identification of SALT observation time that overlaps with scheduled X-ray satellite observations. This is particularly relevant to the optical study of X-ray transients. Since SALT is a fixed elevation telescope, the target visibility is restricted to a circular annulus on the sky covering a total of 1 380 square degrees. In order to identify satellite targets that overlap with SALT visibility, a custom Python program was developed to scrape daily schedules of a number of satellites, and calculate the SALT annulus visibility period of the satellite targets to find overlapping observation time between the satellites and SALT. If a target observation time overlaps in visibility, the relevant information is published to a web page, as well as summarised in an email for dissemination by a mailing list. Transient alerts by email is an old established method, but it clogs inboxes and requires time during the day to evaluate for scheduling — followed by an independent process to request or submit a target for observation to a telescope. It also requires a human in the loop, which will become increasingly challenging as the frequency of alerts increase over time. To streamline the process, from evaluation to submission, SALT (and by extension the SAAO intelligent observatory) is in the midst of developing a prototype TOM for the X-ray transient observations. The aim of the prototype development is to identify and implement the components that will make SALT observations more easily undertaken for the transient community using TOMs1 for target management and observation. The current SALT X-ray transient email alert software, Xsats, contains all the components necessary to migrate to a TOM transient alert interface. Additionally, because the current email alerts have been running for a while, user needs and requirements are already folded into the code; thereby permitting a straight-up mapping onto new technology, using the existing system as independent verification. This paper presents the overall design describing the migration process, as well as application-based development that will be required.
Las Cumbres Observatory (LCOGT) has recently finished integrating the SOAR 4.1-meter telescope into its robotic telescope network. To achieve this, an observation request language was developed suitable for describing observations across a wide range of current and future telescope facilities and observing resources. A complete set of Application Programming Interfaces (APIs) were developed to allow any arbitrary observatory to utilize LCOGT’s observation management software, including interfaces to i) manage proposals, ii) retrieve and update a schedule of observations, iii) report the progress of ongoing observations, iv) propagate operational telemetry and v) receive science products. We describe our efforts, the experience gained, and the implications of this work on the Astronomical Event Observatory Network (AEON) initiative. We also introduce an alternate option for observation management in the open source Observatory Control System (OCS).
With the advent of large-scale time-domain surveys such as the LSST, there is a strong desire for the 4-m SOAR Telescope to be able to respond efficiently and effectively to transient alerts. Enabling the required capabilities at SOAR will also support a greater variety of science programs than conventional telescope scheduling. These capabilities are best deployed with SOAR acting as one of several telescopes responding to alerts and supporting time domain programs. We outline how this might be done if SOAR is included as a node in the Las Cumbres Observatory network, at least part-time. This allows SOAR to make use of extensive existing software infrastructure, while adding a larger aperture to the existing network. Participation of SOAR also serves as a pathfinder for participation of other large telescopes in an evolved LCO network. The overall workflow is outlined. Required interfaces are described. Finally, the initial development efforts with this goal in mind are outlined.
We discuss a generalised model for representing a telescope of arbitrary complexity as a networked resource that could be scheduled by a remote entity. We describe the five interfaces that enable such a telescope to i) accept authorised projects, ii) receive and update a schedule of observations, iii) report progress of ongoing observations, iv) propagate operational telemetry and v) produce retrievable science products. We are using this model to integrate the SOAR 4.1m into the Las Cumbres Observatory (LCOGT) robotic telescope network, and see it as a general approach that could be applied to other telescopes in the future.
Modern astronomical surveys such as the Large Synoptic Sky Survey (LSST) promise an unprecedented wealth of discoveries, delivered in the form of 10 million alerts of time-variable events per night. Astronomers are faced with the daunting challenge of identifying the most scientifically important events from this flood of data in order to conduct effective and timely follow-up observations. Several ongoing observing programs have proven databases to be extremely valuable in conducting efficient follow-up, particularly when combined with tools to select targets, submit observation requests directly to groundand space-based facilities (manual, remotely-operated and robotic), handle the resulting data, interface with analysis software and share information with collaborators. We draw on experience from a number of follow-up programs running at LCOGT, all of which have independently developed systems to provide these capabilities, including the Microlensing Key Project (RoboNet, PI: Tsapras, co-I Street), the Global Supernova Project (SNEx, PI: Howell) and the Near-Earth Object Project (NEOExchange, PI: Lister). We refer to these systems in general as Target and Observation Managers (TOMs). Future projects, facing a much greater and rapidly-growing list of potential targets, will find such tools to be indispensable, but the systems developed to date are highly specialized to the projects they serve and are not designed to scale to the LSST alert rate. We present a project to develop a general-purpose software toolkit that will enable astronomers to easily build TOM systems that they can customize to suit their needs, while a professionally-developed codebase will ensure that the systems are capable of scaling to future programs.
The Las Cumbres Observatory Global Telescope Network comprises nine 1-meter and two 2-meter telescopes, all robotic and dynamically scheduled, at five sites spanning the globe. Instrumentation includes optical imagers and low-dispersion spectrographs. A suite of high-dispersion, high-stability spectrographs is being developed for deployment starting late this year. The network has been designed and built to allow regular monitoring of time-variable or moving objects with any cadence, as well as rapid response to external alerts. Our intent is to operate it in a totally integrated way, both in terms of scheduling and in terms of data quality. The unique attributes of the LCOGT network make it different enough from any existing facility that alternative approaches to optimize science productivity can be considered. The LCOGT network V1.0 began full science operations this year. It is being used in novel ways to undertake investigations related to supernovae, microlensing events, solar system objects, and exoplanets. The network’s user base includes a number of partners, who are providing resources to the collaboration. A key project program brings together many of these partners to carry out large projects. In the long term, our vision is to operate the network as a part of a time-domain system, in which pre-planned monitoring observations are interspersed with autonomously detected and classified events from wide-area surveys.
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