Instrumentation and Methods for Astrophysics (astro-ph.IM)

The PLATO field selection process: II. Characterization of LOPS2, the first long-pointing field

2025-03-28T17:00:27Z

The PLATO field selection process: II. Characterization of LOPS2, the first long-pointing field Nascimbeni, V.; Piotto, G.; Cabrera, J.; Montalto, M.; Marinoni, S.; Marrese, P. M.; Aerts, C.; Altavilla, G.; Benatti, S.; Börner, A.; Deleuil, M.; Desidera, S.; Gizon, L.; Goupil, M. J.; Granata, V.; Heras, A. M.; Magrin, D.; Malavolta, L.; Mas-Hesse, J. M.; Osborn, H. P.; Pagano, I.; Paproth, C.; Pollacco, D.; Prisinzano, L.; Ragazzoni, R.; Ramsay, G.; Rauer, H.; Tkachenko, A.; Udry, S. PLAnetary Transits and Oscillations of stars (PLATO) is an ESA M-class mission to be launched by the end of 2026 to discover and characterize transiting planets around bright and nearby stars, and in particular habitable rocky planets hosted by solar-like stars. Over the mission lifetime, an average of 8% of the science data rate will be allocated to Guest Observer programs selected by ESA through public calls. Hence, it is essential for the community to know in advance where the observing fields will be located. In a previous paper, we identified two preliminary long-pointing fields (LOPN1 and LOPS1) for PLATO, respectively in the northern and southern hemispheres. Here we present LOPS2, a slightly adjusted version of the southern field that has recently been selected by the PLATO Science Working Team as the first field to be observed by PLATO for at least two continuous years, following the scientific requirements. In this paper, we describe the astrophysical content of LOPS2 in detail, including known planetary systems, bright stars, variables, binary stars, star clusters, and synergies with other current and future facilities.

The BlackGEM Telescope Array. I. Overview

2024-12-16T15:28:40Z

The BlackGEM Telescope Array. I. Overview Groot, P. J.; Bloemen, S.; Vreeswijk, P. M.; van Roestel, J. C. J.; Jonker, P. G.; Nelemans, G.; Klein-Wolt, M.; Lepoole, R.; Pieterse, D. L. A.; Rodenhuis, M.; Boland, W.; Haverkorn, M.; Aerts, C.; Bakker, R.; Balster, H.; Bekema, M.; Dijkstra, E.; Dolron, P.; Elswijk, E.; van Elteren, A.; Engels, A.; Fokker, M.; de Haan, M.; Hahn, F.; ter Horst, R.; Lesman, D.; Kragt, J.; Morren, J.; Nillissen, H.; Pessemier, W.; Raskin, G.; de Rijke, A.; Scheers, L. H. A.; Schuil, M.; Timmer, S. T.; Antunes Amaral, L.; Arancibia-Rojas, E.; Arcavi, I.; Blagorodnova, N.; Biswas, S.; Breton, R. P.; Dawson, H.; Dayal, P.; De Wet, S.; Duffy, C.; Faris, S.; Fausnaugh, M.; Gal-Yam, A.; Geier, S.; Horesh, A.; Johnston, C.; Katusiime, G.; Kelley, C.; Kosakowski, A.; Kupfer, T.; Leloudas, G.; Levan, A.; Modiano, D.; Mogawana, O.; Munday, J.; Paice, J.; Patat, F.; Pelisoli, I.; Ramsay, G.; Ranaivomanana, P. T.; Ruiz-Carmona, R.; Schaffenroth, V.; Scaringi, S.; Stoppa, F.; Street, R.; Tranin, H.; Uzundag, M.; Valenti, S.; Veresvarska, M.; Vuc̆ković, M.; Wichern, H. C. I.; Wijers, R. A. M. J.; Wijnands, R. A. D.; Zimmerman, E. The main science aim of the BlackGEM array is to detect optical counterparts to gravitational wave mergers. Additionally, the array will perform a set of synoptic surveys to detect Local Universe transients and short timescale variability in stars and binaries, as well as a six-filter all-sky survey down to ∼22nd mag. The BlackGEM Phase-I array consists of three optical wide-field unit telescopes. Each unit uses an f/5.5 modified Dall-Kirkham (Harmer-Wynne) design with a triplet corrector lens, and a 65 cm primary mirror, coupled with a 110Mpix CCD detector, that provides an instantaneous field-of-view of 2.7 square degrees, sampled at 0.″564 pixel^‑1. The total field-of-view for the array is 8.2 square degrees. Each telescope is equipped with a six-slot filter wheel containing an optimised Sloan set (BG-u, BG-g, BG-r, BG-i, BG-z) and a wider-band 440–720 nm (BG-q) filter. Each unit telescope is independent from the others. Cloud-based data processing is done in real time, and includes a transient-detection routine as well as a full-source optimal-photometry module. BlackGEM has been installed at the ESO La Silla observatory as of 2019 October. After a prolonged COVID-19 hiatus, science operations started on 2023 April 1 and will run for five years. Aside from its core scientific program, BlackGEM will give rise to a multitude of additional science cases in multi-colour time-domain astronomy, to the benefit of a variety of topics in astrophysics, such as infant supernovae, luminous red novae, asteroseismology of post-main-sequence objects, (ultracompact) binary stars, and the relation between gravitational wave counterparts and other classes of transients.

GERry: A code to optimise the hunt for the electromagnetic counter-parts to gravitational wave events

2024-11-08T13:35:25Z

GERry: A code to optimise the hunt for the electromagnetic counter-parts to gravitational wave events O'Neill, David; Lyman, Joseph; Ackley, Kendall; Steeghs, Danny; Galloway, Duncan; Dhillon, Vik; O'Brien, Paul; Ramsay, Gavin; Noysena, Kanthanakorn; Kotak, Rubina; Breton, Rene; Nuttall, Laura; Pallé, Enric; Pollacco, Don; Ulaczyk, Krzysztof; Dyer, Martin; Jiménez-Ibarra, Felipe; Killestein, Tom; Kumar, Amit; Kelsey, Lisa; Godson, Ben; Jarvis, Dan The search for the electromagnetic counterparts to Gravitational Wave (GW) events has been rapidly gathering pace in recent years thanks to the increasing number and capabilities of both gravitational wave detectors and wide field survey telescopes. Difficulties remain, however, in detecting these counterparts due to their inherent scarcity, faintness and rapidly evolving nature. To find these counterparts, it is important that one optimizes the observing strategy for their recovery. This can be difficult due to the large number of potential variables at play. Such follow-up campaigns are also capable of detecting hundreds or potentially thousands of unrelated transients, particularly for GW events with poor localization. Even if the observations are capable of detecting a counterpart, finding it among the numerous contaminants can prove challenging. Here we present the Gravitational wave Electromagnetic RecovRY code (GERRY) to perform detailed analysis and survey-agnostic quantification of observing campaigns attempting to recover electromagnetic counterparts. GERRY considers the campaign's spatial, temporal and wavelength coverage, in addition to Galactic extinction and the expected counterpart light curve evolution from the GW 3D localization volume. It returns quantified statistics that can be used to: determine the probability of having detected the counterpart, identified the most promising sources, and assessed and refine strategy. Here we demonstrate the code to look at the performance and parameter space probed by current and upcoming wide-field surveys such as GOTO and VRO.

The Gravitational-wave Optical Transient Observer (GOTO)

2024-11-08T13:35:25Z

The Gravitational-wave Optical Transient Observer (GOTO) Dyer, Martin J.; Ackley, Kendall; Jiménez-Ibarra, Felipe; Lyman, Joseph; Ulaczyk, Krzysztof; Steeghs, Danny; Galloway, Duncan K.; Dhillon, Vik S.; O'Brien, Paul; Ramsay, Gavin; Noysena, Kanthanakorn; Kotak, Rubina; Breton, Rene; Nuttall, Laura; Pallé, Enric; Pollacco, Don; Killestein, Tom; Kumar, Amit; O'Neill, David; Kelsey, Lisa; Godson, Ben; Jarvis, Dan The Gravitational-wave Optical Transient Observer (GOTO) is a project dedicated to identifying optical counterparts to gravitational-wave detections using a network of dedicated, wide-field telescopes. After almost a decade of design, construction, and commissioning work, the GOTO network is now fully operational with two antipodal sites: La Palma in the Canary Islands and Siding Spring in Australia. Both sites host two independent robotic mounts, each with a field-of-view of 44 square degrees formed by an array of eight 40cm telescopes, resulting in an instantaneous 88 square degree field-of-view per site. All four telescopes operate as a single integrated network, with the ultimate aim of surveying the entire sky every 2-3 days and allowing near-24-hour response to transient events within a minute of their detection. In the modern era of transient astronomy, automated telescopes like GOTO form a vital link between multi-messenger discovery facilities and in-depth follow-up by larger telescopes. GOTO is already producing a wide range of scientific results, assisted by an efficient discovery pipeline and a successful citizen science project: Kilonova Seekers.