Mitigating scanning-induced systematics in Hipparcos and implications for Gaia astrometry
Abstract
Space-based astrometric missions such as Hipparcos and Gaia rely on one-dimensional scanning strategies that couple the measured signals with both observation times and scanning geometry. This coupling can introduce spurious periodicities and complicate their interpretation. We present a non-parametric extension of the phase-distance correlation (PDC) periodogram that quantifies and reduces dependence on scan geometry at the period-search stage. Using Hipparcos data, we identified recurrent periodicities associated with characteristic scanning-law timescales and showed that they are strongly suppressed by the scan-angle-controlled statistic. We then applied the method to Gaia Data Release 4 (DR4) prerelease epoch astrometry, where a recurrent ~54-day feature is suppressed across multiple sources while independently known orbital signals remain detectable. The method provides a diagnostic of scan-angle dependence and a way to mitigate its impact on period searches. These results are particularly relevant for Gaia DR4, where public epoch astrometry will enable large-scale searches for companions ranging from exoplanets to dormant black holes.
Versions
Related
- Mitigating half-wave plate systematics at the map-making level: calibration requirements for LiteBIRD
- Mass-dependent multiplicity fraction in low-mass stars revealed by astrometry Gaia
- Characterization of Planetary Systems with Astrometry
- Setup and performance of focal-plane characterization benches for high precision astrometry
- Bayesian analysis of Gaia epoch astrometry and radial velocities with kima
BibTeX
@misc{binnenfeld2026mitigating,
title = {{Mitigating scanning-induced systematics in Hipparcos and implications for Gaia astrometry}},
author = {Avraham Binnenfeld and Sahar Shahaf and Richard I. Anderson and Hans-Walter Rix and Shay Zucker},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.08282},
eprint = {2611.08282},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.08282},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Mitigating scanning-induced systematics in Hipparcos and implications for Gaia astrometry
AU - Avraham Binnenfeld
AU - Sahar Shahaf
AU - Richard I. Anderson
AU - Hans-Walter Rix
AU - Shay Zucker
PY - 2026
DA - 2026/11/05
PB - arXiv
DO - 10.48550/arxiv.2611.08282
UR - https://arxiv.org/abs/2611.08282
AB - Space-based astrometric missions such as Hipparcos and Gaia rely on one-dimensional scanning strategies that couple the measured signals with both observation times and scanning geometry. This coupling can introduce spurious periodicities and complicate their interpretation. We present a non-parametric extension of the phase-distance correlation (PDC) periodogram that quantifies and reduces dependence on scan geometry at the period-search stage. Using Hipparcos data, we identified recurrent periodicities associated with characteristic scanning-law timescales and showed that they are strongly suppressed by the scan-angle-controlled statistic. We then applied the method to Gaia Data Release 4 (DR4) prerelease epoch astrometry, where a recurrent ~54-day feature is suppressed across multiple sources while independently known orbital signals remain detectable. The method provides a diagnostic of scan-angle dependence and a way to mitigate its impact on period searches. These results are particularly relevant for Gaia DR4, where public epoch astrometry will enable large-scale searches for companions ranging from exoplanets to dormant black holes.
ER -