A Search for Variability of Ultracool Dwarfs with the Zwicky Transient Facility

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Huang, Haomiao, Wang, Shu, Chen, Xiaodian, Tu, Zhijun, Liu, Jifeng
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913085434888192
author Huang, Haomiao
Wang, Shu
Chen, Xiaodian
Tu, Zhijun
Liu, Jifeng
author_facet Huang, Haomiao
Wang, Shu
Chen, Xiaodian
Tu, Zhijun
Liu, Jifeng
contents Rotationally modulated photometric variability of ultracool dwarfs encodes key information about cloud structure and temperature contrasts. Large homogeneous optical datasets are crucial for linking atmospheric heterogeneity to fundamental parameters such as rotation, mass, and age. We present a search for rotation periods in ultracool dwarfs using Zwicky Transient Facility (ZTF) optical light curves. By propagating the coordinates to the ZTF epoch and applying Lomb-Scargle analysis, we identified 226 periodic variables, including 32 robust detections and 194 tentative cases. Among the robust detections, 12 have no previously published periods, while 20 have literature counterparts, most of which are consistent with the published values. Most robust detections are M dwarfs, reflecting the optical sensitivity limits of ZTF. We find a trend of decreasing periods toward later spectral types in relatively old dwarfs (> 100 Myr), suggesting faster rotation for late-M types than for mid-M types. The age-period relation of our sample is broadly consistent with angular-momentum-conservation models at higher-mass regime of brown dwarfs, consistent with the M-dwarf bias of our catalog. Many additional candidates remain to be confirmed due to sparse sampling or low S/N. Future high-cadence, multi-wavelength monitoring and systematic mining of ZTF and upcoming surveys will be crucial for validating these periods, extend sensitivity to later (L/T) types, and better connect rotation with cloud physics across the stellar-substellar boundary.
format Preprint
id arxiv_https___arxiv_org_abs_2605_02216
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A Search for Variability of Ultracool Dwarfs with the Zwicky Transient Facility
Huang, Haomiao
Wang, Shu
Chen, Xiaodian
Tu, Zhijun
Liu, Jifeng
Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
Rotationally modulated photometric variability of ultracool dwarfs encodes key information about cloud structure and temperature contrasts. Large homogeneous optical datasets are crucial for linking atmospheric heterogeneity to fundamental parameters such as rotation, mass, and age. We present a search for rotation periods in ultracool dwarfs using Zwicky Transient Facility (ZTF) optical light curves. By propagating the coordinates to the ZTF epoch and applying Lomb-Scargle analysis, we identified 226 periodic variables, including 32 robust detections and 194 tentative cases. Among the robust detections, 12 have no previously published periods, while 20 have literature counterparts, most of which are consistent with the published values. Most robust detections are M dwarfs, reflecting the optical sensitivity limits of ZTF. We find a trend of decreasing periods toward later spectral types in relatively old dwarfs (> 100 Myr), suggesting faster rotation for late-M types than for mid-M types. The age-period relation of our sample is broadly consistent with angular-momentum-conservation models at higher-mass regime of brown dwarfs, consistent with the M-dwarf bias of our catalog. Many additional candidates remain to be confirmed due to sparse sampling or low S/N. Future high-cadence, multi-wavelength monitoring and systematic mining of ZTF and upcoming surveys will be crucial for validating these periods, extend sensitivity to later (L/T) types, and better connect rotation with cloud physics across the stellar-substellar boundary.
title A Search for Variability of Ultracool Dwarfs with the Zwicky Transient Facility
topic Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
url https://arxiv.org/abs/2605.02216