BHTOM: The Power of Many

Time-domain astronomy, driven by the current wide-field surveys such as ATLAS (Tonry et al., 2018), Pan-STARRS (Chambers et al., 2016) and ZTF (Bellm et al., 2019) has become essential for studying rapidly evolving astrophysical phenomena. The upcoming Legacy Survey of Space and Time (LSST; Ivezic et al. 2019) at the Vera C. Rubin Observatory will also reach fainter objects than the current sky surveys and will revolutionise transient astrophysics, finding thousands of new events every single night. However, these surveys typically follow fixed cadences and revisit fields every few days to weeks, often in different filters, making high-cadence, single-filter monitoring challenging. The Black Hole Target and Observation Manager (BHTOM, bhtom.space; Wyrzykowski 2024) provides an effective complement to survey-based data. BHTOM enables user-defined observation requests for targeted, high-cadence photometric monitoring of individual objects. BHTOM currently accepts requests for targets for long-term or rapid photometric monitoring, such as transients, microlensing events, quasars, variable stars, and extrasolar planets. The BHTOM telescope network is made up of∼120 telescopes all over the world and includes robotic, manual, amateur, and professional facilities, ranging from ∼0.2 m to 2.5 m telescopes. All observations are automatically processed and standardised in BHTOM in order to provide science-ready data. BHTOM is not a broker; rather, it is the missing link between brokers and the telescopes. BHTOM also queries all possible multi-wavelength archives for photometry, maximising the available target information.With the forthcoming release of BHTOM Version 3 (BHTOM 3), the platform is expanding to support solar system targets for the first time. Users will be able to submit target observation requests for comets and asteroids and define epochs. BHTOM 3 will query historical data archives for past observations and coordinate future observing campaigns based on predicted orbital parameters from JPL Horizons. In addition to scheduled monitoring, BHTOM 3 will allow for the rapid deployment of the telescope network in response to alerts from surveys, brokers, or community triggers. Previous high-cadence studies of solar system objects (e.g., Trigo-Rodriguez et al., 2008; Snodgrass et al., 2016; Gillan et al., 2024; Holt et al., 2024) have demonstrated the scientific potential of such coordinated time-domain approaches.BHTOM offers a flexible, scalable, and low-barrier platform for the solar system and broader time-domain communities. By removing the need for individual telescope proposals, providing global sky coverage, and delivering consistent, science-ready data products across diverse instruments, BHTOM facilitates rapid and coordinated observations, enhancing the scientific potential of current and upcoming surveys.ReferencesBellm, Eric C. et al. (Jan. 2019). “The Zwicky Transient Facility: System Overview, Performance, and First Results”. In: 131.995, p. 018002. doi: 10.1088/1538-3873/aaecbe. arXiv: 1902.01932 [astro-ph.IM].Chambers, K. C. et al. (Dec. 2016). “The Pan-STARRS1 Surveys”. In: arXiv e-prints, arXiv:1612.05560, arXiv:1612.05560. doi: 10.48550/arXiv.1612.05560. arXiv: 1612.05560 [astro-ph.IM].Gillan, A. Fraser et al. (Jan. 2024). “Dust Production Rates in Jupiter-family Comets: A Two Year Study with ATLAS Photometry”. In: 5.1,25, p. 25. doi: 10.3847/PSJ/ad1394. arXiv: 2312.06817 [astro-ph.EP].Holt, Carrie E. et al. (Dec. 2024). “Brightness Behavior of Distant Oort Cloud Comets”. In: 5.12, 273, p. 273. doi: 10.3847/PSJ/ad8e38.Ivezi´c, Zeljko et al. (Mar. 2019). “LSST: From Science Drivers to Reference Design and Anticipated Data Products”. In: 873.2, 111, p. 111. doi:10.3847/1538-4357/ab042c. arXiv: 0805.2366 [astro-ph].Snodgrass, Colin et al. (Nov. 2016). “The perihelion activity of comet 67P/Churyumov-Gerasimenko as seen by robotic telescopes”. In: 462, S138–S145. doi: 10 . 1093 / mnras / stw2300. arXiv: 1610 . 06407 [astro-ph.EP].Tonry, J. L. et al. (June 2018). “ATLAS: A High-cadence All-sky Survey System”. In: 130.988, p. 064505. doi: 10 . 1088 / 1538 - 3873 / aabadf.arXiv: 1802.00879 [astro-ph.IM].Trigo-Rodriguez, J. M. et al. (July 2008). “Outburst activity in comets. I. Continuous monitoring of comet 29P/Schwassmann-Wachmann 1”. In: 485.2, pp. 599–606. doi: 10.1051/0004-6361:20078666.Wyrzykowski, Lukasz (Jan. 2024). “Power of many - BHTOM telescope network for time-domain astronomy”. In: What Was That? - Planning ESO Follow up for Transients, Variables, and Solar System Objects in the Era of LSST, 4, p. 4. doi: 10.5281/zenodo.10571539.