Understanding　the　non-Newtonian　Casson　fluid　is　crucial　for　addressing　various　challenges　in　industrial,　biological,　and　environmental　applications.　In　this　novel　research,　Casson　fluid　with　temperature-dependent　variable　thermal　conductivity　is　analyzed　by　a　natural　convective　plume　generated　by　horizontal　line　heat　source.　The　plume　system　is　under　the　influence　of　solar　radiation　and　an　aligned　magnetic　field.　The　momentum　equation　is　transmuted　for　Casson　fluid,　while　energy　equation　transmuted　for　solar　radiation　and　variable　thermal　conductivity.　The　coupled　partial　differential　equations　changed　into　ordinary　differential　equation　by　employing　stream　function　formulation.　For　computational　evaluation,　bvp4c　built-in　tool　of　MATLAB　is　employed　in　combination　with　Shooting　technique　in　order　to　analyze　both　missing　and　specified　boundary　conditions.　The　upshots　of　Casson　parameter　beta　1,　thermal　conductivity　variable　gamma　1,　radiation　parameter　Rd,　magnetic　force　parameter　S,　Prandtl　number　Pr　and　magnetic　Prandtl　number　gamma　on　specified　and　missing　conditions　are　highlighted　in　the　graphical　illustrations.　The　computed　outcomes　for　missing　conditions　depicts　that　for　Casson　parameter　beta　1　velocity　f　＇　and　temperature　theta　drops　while　current　density　increased　with　increment　in　beta　1.　Whereas,　for　specified　boundary　conditions,　the　skin　friction　f　＇＇　and　magnetic　flux　phi　＇　decreases　while　heat　transfer　rate　theta　＇　enhances　for　increasing　beta　1.　For　missing　conditions,　the　increasing　thermal　conductivity　variable　gamma　1　causes　velocity　f　＇,　current　density　phi　＇＇,　and　temperature　theta　to　drop.　While　for　specified　conditions,　the　skin　friction　f　＇＇,　magnetic　flux　phi　＇　increases　but　heat　transfer　rate　theta　＇　exhibits　reverse　trend　with　enhancing　gamma　1.　Additionally,　a　validation　analysis　has　been　performed　by　comparing　the　values　of　f　＇(0)　for　various　values　of　Pr　with　prior　work,　while　excluding　the　other　parameters　to　check　its　limitations　at　the　boundary　layer.