H β Spicules, Small-scale Jets, and H β Microflashes: Subarcsecond Dynamic Events and Their Magnetic Origins in the Lower Solar Chromosphere Observed by DKIST
7 affiliations
- 1Lockheed Martin Solar and Astrophysics Laboratory
- 2SETI Institute
- 3New Mexico State University
- 4Bay Area Environmental Research Institute
- 5NASA Marshall Space Flight Center
- 6Center for Space Plasma and Aeronomic Research (CSPAR)
- 7National Solar Observatory
Abstract
We examine an on-disk solar quiet region of enhanced magnetic network using H β images from Daniel K. Inouye Solar Telescope’s (DKIST’s) Visible Broadband Imager (VBI) and line-of-sight magnetograms from DKIST’s Visible Spectro-Polarimeter (ViSP). We also compare the ViSP magnetograms with coaligned cotemporal line-of-sight magnetograms from the Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI). We find (i) two types of chromospheric jet-like features: H β spicules and small-scale jets. Both are rooted near edges of magnetic network lanes. Several sit close to ViSP-detected tiny islands of either minority-polarity flux or dips in majority-polarity flux; hence, they plausibly stem from mixed-polarity magnetic flux and are caused by chromospheric magnetic reconnection. For H β spicules, the average width, length, lifetimes, and speeds are 420 ± 400 km, 2600 ± 1600 km, 4.3 ± 0.25 minutes, and 12 ± 4.7 km s ⁻¹ . For small-scale jets, they are 385 ± 100 km, 620 ± 40 km, 5 ± 3 minutes, and 4.4 ± 1.5 km s ⁻¹ . (ii) H β microflashes sit in evidently unipolar flux. Their widths, lengths, lifetimes, and speeds are 180 ± 65 km, 365 ± 100 km, 4.3 ± 2.6 minutes, and 3.1 ± 0.2 km s ⁻¹ . (iii) At the base of a coronal plume, due to its higher spatial resolution than HMI, ViSP shows both some very strong (>800 G) majority-polarity flux not shown by HMI and some subarcsecond minority-polarity flux inclusions not shown by HMI. These subarcsecond chromospheric transients carry sufficient energy (≃10 ²⁴ erg) to transiently heat the local chromosphere and corona and potentially contribute to solar wind acceleration. They may represent the small-scale end of a continuum of magnetic-reconnection-driven activity, highlighting the importance of DKIST’s high-resolution magnetic field measurements for understanding small-scale chromospheric dynamics.
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BibTeX
@article{panesar2026spicules,
title = {{H β Spicules, Small-scale Jets, and H β Microflashes: Subarcsecond Dynamic Events and Their Magnetic Origins in the Lower Solar Chromosphere Observed by DKIST}},
author = {Navdeep K. Panesar and V. Aparna and Sanjiv K. Tiwari and Alphonse C. Sterling and Ronald L. Moore and J. M. da Silva Santos},
journal = {The Astrophysical Journal Letters},
year = {2026},
month = oct,
doi = {10.3847/2041-8213/aea156},
url = {https://iopscience.iop.org/article/10.3847/2041-8213/aea156},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - H β Spicules, Small-scale Jets, and H β Microflashes: Subarcsecond Dynamic Events and Their Magnetic Origins in the Lower Solar Chromosphere Observed by DKIST
AU - Navdeep K. Panesar
AU - V. Aparna
AU - Sanjiv K. Tiwari
AU - Alphonse C. Sterling
AU - Ronald L. Moore
AU - J. M. da Silva Santos
PY - 2026
DA - 2026/10/26
JO - The Astrophysical Journal Letters
DO - 10.3847/2041-8213/aea156
UR - https://iopscience.iop.org/article/10.3847/2041-8213/aea156
AB - We examine an on-disk solar quiet region of enhanced magnetic network using H β images from Daniel K. Inouye Solar Telescope’s (DKIST’s) Visible Broadband Imager (VBI) and line-of-sight magnetograms from DKIST’s Visible Spectro-Polarimeter (ViSP). We also compare the ViSP magnetograms with coaligned cotemporal line-of-sight magnetograms from the Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI). We find (i) two types of chromospheric jet-like features: H β spicules and small-scale jets. Both are rooted near edges of magnetic network lanes. Several sit close to ViSP-detected tiny islands of either minority-polarity flux or dips in majority-polarity flux; hence, they plausibly stem from mixed-polarity magnetic flux and are caused by chromospheric magnetic reconnection. For H β spicules, the average width, length, lifetimes, and speeds are 420 ± 400 km, 2600 ± 1600 km, 4.3 ± 0.25 minutes, and 12 ± 4.7 km s ⁻¹ . For small-scale jets, they are 385 ± 100 km, 620 ± 40 km, 5 ± 3 minutes, and 4.4 ± 1.5 km s ⁻¹ . (ii) H β microflashes sit in evidently unipolar flux. Their widths, lengths, lifetimes, and speeds are 180 ± 65 km, 365 ± 100 km, 4.3 ± 2.6 minutes, and 3.1 ± 0.2 km s ⁻¹ . (iii) At the base of a coronal plume, due to its higher spatial resolution than HMI, ViSP shows both some very strong (>800 G) majority-polarity flux not shown by HMI and some subarcsecond minority-polarity flux inclusions not shown by HMI. These subarcsecond chromospheric transients carry sufficient energy (≃10 ²⁴ erg) to transiently heat the local chromosphere and corona and potentially contribute to solar wind acceleration. They may represent the small-scale end of a continuum of magnetic-reconnection-driven activity, highlighting the importance of DKIST’s high-resolution magnetic field measurements for understanding small-scale chromospheric dynamics.
SN - 2041-8205
SN - 2041-8213
ER -