Can we constrain the binary neutron star merger time from kilonova light curves?
Abstract
The joint observation of gravitational waves (GWs) from a binary neutron star (BNS) merger (GW170817), together with a short Gamma-Ray Burst (GRB 170817A) and a kilonova (KN, AT2017gfo), marked the birth of multimessenger astronomy with GWs, and demonstrated the informative power of multimessenger observations. More BNS merger and KN detections are expected , thanks to the increasing sensitivity of GW detectors and the advent of new electromagnetic facilities such as the Vera C. Rubin Observatory. However, the association between a BNS merger and a KN might not be trivial: the detection of a KN might not coincide with the onset of the EM emission, making it difficult to define a temporal window to assess the coincidence with a GW event. In this work we investigate the possibility to constrain the BNS merger time from KN light curves, exploring different observing conditions and with focus on the Vera C. Rubin Observatory. We used different KN models and different inference frameworks to simulate and fit KN light curves. We explored different cadences and wavelength coverages for observations, to investigate how the different observing conditions can affect the capability to recover the BNS merger time. The tests performed also include real data related to AT2017gfo, plus a few GRBs that have been associated to possible KN candidates. We find that, under realistic observing conditions with the Vera C. Rubin Observatory, the BNS merger time can be recovered with a precision of 5.5 days (90\% CI) with a best-case scenario with an accuracy of 0.18 day and a precision of 0.74 day (90 \% CI). Results can slightly improve (by ∼ 5 \%) if the source redshift is available. Upper limits near the merger time can also improve the results, reducing the width of the posterior by ∼60 \%. The BNS merger time estimate could also benefit from EM follow-up observations with other telescopes.
Related
- A Hybrid Neural Network Emulator for M1 Neutrino Reaction Rates in Binary Neutron Star Merger Simulations
- A first-principles binary neutron star merger model of GW170817, GRB170817A, and AT2017gfo
- Detectability of bulk viscosity effects on post-merger gravitational wave signals from binary neutron star mergers
- Funnel Leakage of the Wien Fireball in the Early Nebula after a Binary Neutron Star Merger
- Free Neutron Decay in Kilonova Ejecta: X-ray/UV Flashes with Non-Thermal Effects
BibTeX
@misc{jamsin2026constrain,
title = {{Can we constrain the binary neutron star merger time from kilonova light curves?}},
author = {Noah Jamsin and Marion Pillas and Marko Ristić and Laurence E. H. Datrier and Daniel Brethauer and Stefano Ascenzi and Mattia Bulla and Barbara Patricelli and Silvia Piranomonte and Henrik Rose and Nikhil Sarin and Thibeau Wouters and Khun Sang Phukon and Alex Jacquesson and Samuele Ronchini and Alberto Revilla-Peña and Tyler Barna and Michael W. Coughlin and Tim Dietrich and Richard O'Shaughnessy and Fabio Ragosta},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.28775},
eprint = {2610.28775},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.28775},
}
RIS
TY - UNPB
TI - Can we constrain the binary neutron star merger time from kilonova light curves?
AU - Noah Jamsin
AU - Marion Pillas
AU - Marko Ristić
AU - Laurence E. H. Datrier
AU - Daniel Brethauer
AU - Stefano Ascenzi
AU - Mattia Bulla
AU - Barbara Patricelli
AU - Silvia Piranomonte
AU - Henrik Rose
AU - Nikhil Sarin
AU - Thibeau Wouters
AU - Khun Sang Phukon
AU - Alex Jacquesson
AU - Samuele Ronchini
AU - Alberto Revilla-Peña
AU - Tyler Barna
AU - Michael W. Coughlin
AU - Tim Dietrich
AU - Richard O'Shaughnessy
AU - Fabio Ragosta
PY - 2026
DA - 2026/10/20
PB - arXiv
DO - 10.48550/arxiv.2610.28775
UR - https://arxiv.org/abs/2610.28775
AB - The joint observation of gravitational waves (GWs) from a binary neutron star (BNS) merger (GW170817), together with a short Gamma-Ray Burst (GRB 170817A) and a kilonova (KN, AT2017gfo), marked the birth of multimessenger astronomy with GWs, and demonstrated the informative power of multimessenger observations. More BNS merger and KN detections are expected , thanks to the increasing sensitivity of GW detectors and the advent of new electromagnetic facilities such as the Vera C. Rubin Observatory. However, the association between a BNS merger and a KN might not be trivial: the detection of a KN might not coincide with the onset of the EM emission, making it difficult to define a temporal window to assess the coincidence with a GW event. In this work we investigate the possibility to constrain the BNS merger time from KN light curves, exploring different observing conditions and with focus on the Vera C. Rubin Observatory. We used different KN models and different inference frameworks to simulate and fit KN light curves. We explored different cadences and wavelength coverages for observations, to investigate how the different observing conditions can affect the capability to recover the BNS merger time. The tests performed also include real data related to AT2017gfo, plus a few GRBs that have been associated to possible KN candidates. We find that, under realistic observing conditions with the Vera C. Rubin Observatory, the BNS merger time can be recovered with a precision of 5.5 days (90\% CI) with a best-case scenario with an accuracy of 0.18 day and a precision of 0.74 day (90 \% CI). Results can slightly improve (by ∼ 5 \%) if the source redshift is available. Upper limits near the merger time can also improve the results, reducing the width of the posterior by ∼60 \%. The BNS merger time estimate could also benefit from EM follow-up observations with other telescopes.
ER -