An Optical Gamma-Ray Burst Catalogue with Measured Redshift PART I: Data Release of 535 Gamma-Ray Bursts and Colour Evolution

; M. H. Siegel 26 ; K. Misra 27 ; Andrea Rossi 28 ; C. Lopresti 29 ; U. Quadri 30 ; L. Strabla 30 ; N. Ruocco 31 ; S. Leonini 32 ; M. Conti 32 ; P. Rosi 32 ; L. M. T. Ramirez 32 ; S. Zola 33 ; I. Jindal 34 ; L. Chan 35 ; M. Fuentes 36 ; G. Lambiase 37 ; K. K. Kalinowski 38 ; W. Jamal 39 ; R. Kumar 40 1 National Astronomical Observatory of Japan 2 Università degli Studi di Salerno 3 Universite Cote D’Azur, University of Rome ”Tor Vergata” 4 Indian Institute of Technology Hyderabad 5 Zentrum für Astronomie der Universität Heidelberg, Indian Institute of Science Education and Research Kolkata 6 California Institute of Technology 7 University of Western Australia 8 University of Tokyo 9 Universidad Nacional Autónoma de México 10 Università degli Studi di Roma, Tor Vergata 11 Monash University 12 National Institute of Science Education and Research Bhubaneswar 13 ICRANet, Piazza della Repubblica 10, I-65122 Pescara, Italy 14 University of Birmingham 15 NASA Goddard Space Flight Center, University of Maryland Space Research Insitute (IKI) 17 Space Research Institute of the Russian Academy of Sciences (IKI) 18 Instituto de Astrofísica de Andalucía (IAA-CSIC), INAF - Osservatorio Astronomico di Brera 19 Instituto de Astrofísica de Andalucía (IAA-CSIC), Universidad de Málaga 20 OrangeWave Innovative Science, Etelman Observatory Research Center 21 Instituto de Astronomia, UNAM 22 Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) Program - RIKEN 23 Arizona State University 24 NASA Goddard Space Flight Center, University of Maryland 25 UCO/Lick Observatory, University of California 26 Pennsylvania State University 27 ARIES 28 Istituto Nazionale di Astrofisica (INAF) 29 GAD-Gruppo Astronomia Digitale 30 Osservatorio Bassano Bresciano 31 Osservatorio Astronomico “Nastro Verde” 32 Montarrenti Observatory 33 Astronomical Observatory, Jagiellonian University 34 Indian Institute of Technology Kharagpur 35 Assets High School, Honolulu 36 University of Michigan 37 Universitá di Salerno, INFN-Napoli 38 Aarhus University, Jagiellonian University 39 Lebanese International University 40 Indian Institute of Technology Kanpur We present the largest optical photometry compilation of Gamma-Ray Bursts (GRBs) with measured redshifts (z). Our dataset includes 64813 observations of 535 events (including upper limits) from 28 February 1997 to 18 August 2023. We introduce grbLC, a user-friendly web tool for visualising photometry, coordinates, redshift, host-galaxy extinction, and spectral indices for each event in our database. Additionally, we have integrated a Gamma-ray Coordinate Network (GCN) scraper within grbLC to automate the collection of magnitudes from GCN circulars. The web tool also includes a Python package for uniformly investigating colour evolution in GRBs. We compute the optical spectral indices of 138 GRBs, and craft a novel procedure to infer the presence of colour evolution in GRBs. By providing a standardised format and a centralised repository for optical photometry, our web-based archive represents a significant step towards unifying various community efforts to collect GRB photometric data. This comprehensive catalogue facilitates population studies by offering light curves (LCs) with improved coverage, as it aggregates data from multiple groundbased observatories and the Swift satellite. Consequently, these LCs can be employed to train future LC reconstructions, for an extended inference of the redshift. The data gathering also allows us to fill orbital gaps in the Swift observations, particularly at critical points in the LCs, such as the end of the plateau emission or the identification of jet breaks. Extended theories of electromagnetism and their impact on laboratory experiments and as-