Spectroscopic analysis of hydrogen and silicon in bright fireballs: New insights into meteoroid composition

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00643786" target="_blank" >RIV/67985815:_____/25:00643786 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0373775" target="_blank" >https://hdl.handle.net/11104/0373775</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202556816" target="_blank" >10.1051/0004-6361/202556816</a>

Result language

angličtina

Original language name

Spectroscopic analysis of hydrogen and silicon in bright fireballs: New insights into meteoroid composition

Original language description

We present a study of the high-temperature spectral component in meteor fireballs, with a particular focus on neutral hydrogen (H alpha at 656.28 nm) and ionised silicon (Si II-2 doublet at 634.71 nm and 637.14 nm). By analysing spectra from the European Fireball Network (EN) that exhibit H alpha and Si II-2 emissions, we investigated the relationship between hydrogen and silicon abundances across different meteoroid types. The plasma temperature of the high-temperature component remains independent of meteor velocity. This allows us to directly compare relative intensities of hydrogen, bound in more volatile materials, with silicon, bound in less volatile materials, in bodies with different velocities.Methods. We analysed 31 meteor spectra from the EN, focusing on H alpha (656.28 nm) and Si II-2 (634.71 nm, 637.14 nm) emissions to determine the elemental abundances and their relationships with the meteor parameters. The spectroscopic data were reduced following established procedures to derive the line intensities. We employed direct line integration and applied ionisation corrections through Saha equations to estimate the relative atomic abundances.Results. Our results confirmed that the H/Si value remains largely independent of meteor velocity. We show a positive correlation with photometric mass for cometary meteoroids, suggesting that larger bodies better preserve their volatile content, namely hydrogen. This correlation persists across the meteor showers, showing a physical process related to volatile preservation rather than specific parent body composition. Our data suggest that the abundance of hydrogen in large cometary meteoroids is not only higher than in CI chondrites, but is also comparable to or higher than the measured abundances in small particles of dust from Halley's comet, depending on the assumed plasma conditions. This work brought new constraints on the distribution and preservation of volatile elements in Solar System bodies and new insights into the potential delivery mechanisms of water to Earth.Conclusions. The H/Si values show no correlation with meteor velocity, but increase with photometric mass for cometary meteoroids. The prevalence of hydrogen in larger cometary meteoroids supports models where comets could be significant contributors to Earth's volatile inventory.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GA24-10143S" target="_blank" >GA24-10143S: Detailed insight into the properties of meteor showers</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

704

Issue of the periodical within the volume

Dec.

Country of publishing house

FR - FRANCE

Number of pages

16

Pages from-to

A241

UT code for WoS article

001643295900006

EID of the result in the Scopus database

2-s2.0-105025662333