{"id":40205,"date":"2026-02-23T19:24:57","date_gmt":"2026-02-23T18:24:57","guid":{"rendered":"https:\/\/karmaka.de\/?p=40205"},"modified":"2026-02-23T19:24:57","modified_gmt":"2026-02-23T18:24:57","slug":"thermophysical-modeling-of-asteroid-15-eunomia-from-spatially-resolved-alma-and-vla-data","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=40205","title":{"rendered":"Thermophysical Modeling of Asteroid (15) Eunomia from Spatially Resolved ALMA and VLA Data<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Yu Yu Phua, Katherine de Kleer, Bryan Butler, Saverio Cambioni and Michael Shepard<\/p>\n\n\n\n<p>The Planetary Science Journal, Volume 7, Number 2, Published: 23 February 2026<\/p>\n\n\n\n<p><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/PSJ\/ae3751\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/PSJ\/ae3751\/pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (DOWNLOAD)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Asteroid (15) Eunomia is the largest S-type asteroid in the main belt and the largest member of the Eunomia asteroid family. Previous visible-to-mid-infrared data suggested that Eunomia\u2019s hemispheres have different olivine-to-pyroxene ratios and that \u223c2% of asteroids in its family belong to the X-complex, a taxonomic class possibly associated with iron meteorites. This led to the proposal that Eunomia is partially differentiated. In this work, we searched for metallic regions on Eunomia&#8217;s surface diagnostic of differentiation by analyzing new brightness temperature data collected with the Atacama Large Millimeter\/Submillimeter Array (ALMA) at 1.3 mm and the Karl G. Jansky Very Large Array at 1 and 2 cm, which are particularly sensitive to surface metal content. The ALMA data are resolved at 30 km and allow us to characterize spatial variations in surface properties. We derived best-fit disk-averaged thermal inertia \u0393 = 75\u2013135 J m\u22122 s\u22120.5 K\u22121 and dielectric constant epsilon = 7\u20138 (X\u00b2r=15.5; high X\u00b2r could be due to insufficient data quality or large-scale topography not captured by the shape model). The thermal inertia derived here from 1.3 mm observations may be different from that derived from mid-infrared observations, as the ALMA observations at 1.3 mm probe deeper into the subsurface than mid-infrared observations, where the regolith properties may be different. We do not find hemispherical-scale variations in the thermal inertia and dielectric constant. This suggests that the metal contents of any distinct olivine-rich and pyroxene-rich regions are not significantly different. Overall, our results do not provide conclusive evidence for the state of differentiation of Eunomia.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Yu Yu Phua, Katherine de Kleer, Bryan Butler, Saverio Cambioni and Michael Shepard The Planetary Science Journal, Volume 7, Number 2, Published: 23 February 2026 LINK (OPEN ACCESS)PDF (DOWNLOAD) &#8220;Asteroid (15) Eunomia is the largest&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,214,3035,1184,6320],"tags":[7083,1854,1673,6242],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/40205"}],"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=40205"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/40205\/revisions"}],"predecessor-version":[{"id":40206,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/40205\/revisions\/40206"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=40205"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=40205"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=40205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}