diff --git a/assets/shaders/celestial.frag.glsl b/assets/shaders/celestial.frag.glsl
index 8ccd7eb7..a3d673b9 100644
--- a/assets/shaders/celestial.frag.glsl
+++ b/assets/shaders/celestial.frag.glsl
@@ -37,8 +37,8 @@ void main() {
     // Combine disc and glow
     float alpha = max(disc, glow) * push.intensity;
 
-    // Fade to zero at quad edges to prevent visible box
-    float edgeFade = 1.0 - smoothstep(0.4, 0.5, dist);
+    // Fade to zero well before quad edges
+    float edgeFade = 1.0 - smoothstep(0.35, 0.48, dist);
     alpha *= edgeFade;
 
     vec3 color = push.celestialColor.rgb;
@@ -56,6 +56,7 @@ void main() {
     float phaseShadow = smoothstep(-0.1, 0.1, phaseX);
     alpha *= mix(phaseShadow, 1.0, step(0.5, push.intensity));
 
-    if (alpha < 0.001) discard;
-    outColor = vec4(color, alpha);
+    if (alpha < 0.003) discard;
+    // Pre-multiply for additive blending: RGB is the light contribution
+    outColor = vec4(color * alpha, alpha);
 }
diff --git a/assets/shaders/celestial.frag.spv b/assets/shaders/celestial.frag.spv
index d5875791..9716ef19 100644
Binary files a/assets/shaders/celestial.frag.spv and b/assets/shaders/celestial.frag.spv differ
diff --git a/src/rendering/celestial.cpp b/src/rendering/celestial.cpp
index 34090fe5..798ac5d5 100644
--- a/src/rendering/celestial.cpp
+++ b/src/rendering/celestial.cpp
@@ -85,7 +85,7 @@ bool Celestial::initialize(VkContext* ctx, VkDescriptorSetLayout perFrameLayout)
         .setTopology(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST)
         .setRasterization(VK_POLYGON_MODE_FILL, VK_CULL_MODE_NONE)
         .setDepthTest(true, false, VK_COMPARE_OP_LESS_OR_EQUAL) // test on, write off (sky layer)
-        .setColorBlendAttachment(PipelineBuilder::blendAlpha())
+        .setColorBlendAttachment(PipelineBuilder::blendAdditive())
         .setMultisample(vkCtx_->getMsaaSamples())
         .setLayout(pipelineLayout_)
         .setRenderPass(vkCtx_->getImGuiRenderPass())
@@ -157,7 +157,7 @@ void Celestial::recreatePipelines() {
         .setTopology(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST)
         .setRasterization(VK_POLYGON_MODE_FILL, VK_CULL_MODE_NONE)
         .setDepthTest(true, false, VK_COMPARE_OP_LESS_OR_EQUAL)
-        .setColorBlendAttachment(PipelineBuilder::blendAlpha())
+        .setColorBlendAttachment(PipelineBuilder::blendAdditive())
         .setMultisample(vkCtx_->getMsaaSamples())
         .setLayout(pipelineLayout_)
         .setRenderPass(vkCtx_->getImGuiRenderPass())