Luminosities and Spectra of Meteors

Бронштен, В. А.

doi:10.1007/978-94-009-7222-3_5

Cited by 6 publications

(10 citation statements)

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“…There is no sign of differential ablation as expected from the evaporation of a progressively hotter molten meteoroid (Brö nshten, 1983). In early parts of the meteor leading up to the peak of the flare, all metals are observed to be released from the meteoroid in the same relative ratio.…”

Section: Abundancesmentioning

confidence: 90%

Quantitative meteor spectroscopy: Elemental abundances

Jenniskens

2007

Advances in Space Research

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Section: Abundancesmentioning

confidence: 90%

Quantitative meteor spectroscopy: Elemental abundances

Jenniskens

2007

Advances in Space Research

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“…The difference in the calculated N 2 1 abundance between the two meteors is not a significant argument against the N 2 1 identification (see below). Bronshten (1983) pointed out that the low abundance could be the result of a higher than expected electron density: Although N 2 1 is formed by electron impact on N 2 molecules: N 2 1 e R N 2 1 1 2e…”

Section: Discussionmentioning

confidence: 99%

“…However, that observation was never confirmed with modern techniques. The first negative bands were never found in bright (approximately -5 magnitude) meteors (Bronshten, 1983).…”

Section: The Case For N 2mentioning

confidence: 92%

“…Unlike "Homerun," this meteor track had no abrupt end: The second order O I and N I lines faded gradually after a broad emission flare. The onset of the flare was marked by a sudden onset of Ca 1 emission at 393.4 and 397.0 nm, observed in fourth order, a signature of fast and bright meteors (Harvey, 1971;Bronshten, 1983). Ca 1 emission is thought to arise from a different high temperature (,10,000 K) component rather than from other emission lines (Borovic Ï ka, 1994).…”

Section: Temporal Evolution Of the Bands Along The Meteor Trackmentioning

confidence: 99%

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Search for the OH (X²Π) Meinel Band Emission in Meteors as a Tracer of Mineral Water in Comets: Detection of N₂⁺ (A-X)

Jenniskens

Laux

2004

Astrobiology

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We report the discovery of the N(2)(+) A-X Meinel band in the 780-840 nm meteor emission from two Leonid meteoroids that were ejected less than 1000 years ago by comet 55P/Tempel-Tuttle. Our analysis indicates that the N(2)(+) molecule is at least an order of magnitude less abundant than expected, possibly as a result of charge transfer reactions with meteoric metal atoms. This new band was found while searching for rovibrational transitions in the X(2)Pi electronic ground state of OH (the OH Meinel band), a potential tracer of water bound to minerals in cometary matter. The electronic A-X transition of OH has been identified in other Leonid meteors. We did not detect this OH Meinel band, which implies that the excited A state is not populated by thermal excitation but by a mechanism that directly produces OH in low vibrational levels of the excited A(2)Sigma state. Ultraviolet dissociation of atmospheric or meteoric water vapor is such a mechanism, as is the possible combustion of meteoric organics.

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“…Additionally, a hot T = 10 000 K component has been detected in meteor spectra, of which the most well-known emissions are the ionized Mg II line at 448.2 run, the ionized Fe II lines at 458.4 and 501.8 urn, the Ca II doublet at 393.4 and 396.8 run, the Si II lines at 634.9 and 637.3 run, as well as the neutral H I lines at 656.4 and 486.3 urn (Bronshten, 1983;Borovicka, 1993Borovicka, , 1994aBorovicka and Bocek, 1995;Borovicka and Betlem, 1997). These emission lines progressively increase in intensity with meteor brightness compared to those from the cooler gas within a single meteor (Cook and Millman, 1954;Harvey, 1971; from the Ca II/Mg I ratio) and with larger Leonid meteoroid mass ; from the Mg II/Mg I line ratio).…”

Section: Introductionmentioning

confidence: 99%

Spaceborne ultraviolet 251–384 nm spectroscopy of a meteor during the 1997 Leonid shower

Jenniskens

Tedesco²,

Murthy

et al. 2002

Meteorit & Planetary Scien

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Abstract-We used the ultraviolet to visible spectrometers onboard the midcourse space experiment to obtain the first ultraviolet spectral measurements ofa bright meteor during the 1997 Leonid shower. The meteor was most likely a Leonid with a brightness of about -2 magnitude at 100 km altitude. In the region between 251 and 310 nm, the two strongest emission lines are from neutral and ionized magnesium. Ionized Ca lines, indicative of a hot T = 10 000 K plasma, are not detected. The Mg and Mg" line intensity ratio alone does not yield the ionization temperature, which can be determined only by assuming the electron density. A typical air plasma temperature of T = 4400 K would imply a very high electron density: n e = 2.2 x 10 18 m-3, but at chondritic abundances ofFe/Mg and Si/Mg =1.For a more reasonable local-thermodynamic-equilibrium (LTE) air plasma electron density, the Mg and Mg! line ratio implies a less than chondritic Fe/Mg = 0.06 abundance ratio and a cool non-LTE T= 2830 K ionization temperature for the ablation vapor plasma. The present observations do not permit a choice between these alternatives. The new data provide also the first spectral confirmation of the presence of molecular OR and NO emission in meteor spectra.

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Luminosities and Spectra of Meteors

Cited by 6 publications

References 0 publications

Quantitative meteor spectroscopy: Elemental abundances

Quantitative meteor spectroscopy: Elemental abundances

Search for the OH (X²Π) Meinel Band Emission in Meteors as a Tracer of Mineral Water in Comets: Detection of N₂⁺ (A-X)

Spaceborne ultraviolet 251–384 nm spectroscopy of a meteor during the 1997 Leonid shower

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Luminosities and Spectra of Meteors

Cited by 6 publications

References 0 publications

Quantitative meteor spectroscopy: Elemental abundances

Quantitative meteor spectroscopy: Elemental abundances

Search for the OH (X2Π) Meinel Band Emission in Meteors as a Tracer of Mineral Water in Comets: Detection of N2+ (A-X)

Spaceborne ultraviolet 251–384 nm spectroscopy of a meteor during the 1997 Leonid shower

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Search for the OH (X²Π) Meinel Band Emission in Meteors as a Tracer of Mineral Water in Comets: Detection of N₂⁺ (A-X)