LINK<\/strong><\/a><\/p>\n\n\n\n“Highlights<\/p>\n\n\n\n
\u2022 Eight iron meteoroids were found among 220 fireball spectra.
\n\u2022 cm-sized iron meteoroids have diverse asteroidal orbits.
\n\u2022 According to end heights, iron fireballs are classified as types IIIA and IIIB.
\n\u2022 Two different ablation and fragmentation models were applied to the data.
\n\u2022 Decay of large number of droplets can explain quick decrease of light at the end.”<\/p>\n\n\n\n
“We collected meteors with iron spectra observed by the newly developed Spectral Digital Autonomous Fireball Observatories (SDAFO). SDAFOs are run within the European Fireball Network and extend the spectral observation of this network. Iron meteoroids can be distinguished using their spectra by the absence of lines of Na, Mg, Cr, Ca, and other usually bright lines of meteoritic origin.<\/p>\n\n\n\n
Among 220 fireball spectra that were observed by SDAFOs in 2015\u20132019 and that showed at least three spectral lines, eight were meteors with iron spectra. We added to the collection one additional iron meteor, which was observed with Digital Autonomous Observatories (DAFO: non\u2013spectral cameras), the iron spectrum of which was observed with the spectral cameras of the AMOS Network (Matlovi\u010d et al., 2019).<\/p>\n\n\n\n
We present atmospheric trajectories, light curves, and heliocentric orbits of these iron fireballs. The orbits are asteroidal, or Sun approaching, and show diversity similar to those of mm\u2013sized iron meteoroids. The inclinations vary from nearly zero up to \u224870\u00b0. The maximum brightness of all fireballs was between magnitude \u22126 and \u221210, corresponding to meteoroid diameters about 1\u20134\u202fcm. Seven fireballs were classified as type IIIA, and two fireballs were classified as type IIIB in the classification of Ceplecha and McCrosky (1976), pointing out, at least formally, to fragile bodies comparable in strength to cometary meteoroids.<\/p>\n\n\n\n
The newly developed model of ablation of small iron meteoroids (\u010capek et al., 2019) is based on the spraying of liquid iron from the meteoroid surface. The model was able to derive unambiguous physical properties only for some of the studied cm-sized bodies. Another model, the semi\u2013empirical model of meteoroid fragmentation, was used to fit the light curves. The erosion included in the model was able to fit the light curves by manually adjusting erosion parameters. To describe the sudden drop at the end of the light curve, it was necessary to progressively increase the erosion coefficient and decrease fragment masses along the trajectory.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Vlastimil Voj\u00e1\u010dek, Ji\u0159\u00ed Borovi\u010dka, Pavel Spurn\u00fd, David \u010capek Planetary and Space Science LINK “Highlights \u2022 Eight iron meteoroids were found among 220 fireball spectra. \u2022 cm-sized iron meteoroids have diverse asteroidal orbits. \u2022 According to…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[214,96],"tags":[871,880,118,2468,4466,5456,5455,5457,3712,3482],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21541"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=21541"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21541\/revisions"}],"predecessor-version":[{"id":21542,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21541\/revisions\/21542"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21541"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21541"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21541"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}