Draw every star at its own radius, measured where the archive has one and derived otherwise

The system view drew the Sun at its own radius and every other star at 0.45 of its innermost
orbit, capped at 0.2 AU: a size chosen so the star would not swallow its planets, not the star's.
Proxima Centauri was drawn at 2.8 solar radii, eighteen times its own, and every star without
planets at 43.

starSurfaceOf (body-view-model.ts) now gives each star a radius and a temperature. A planet host
takes the archive's st_rad and st_teff from its planets' rows: 4 439 hosts are drawn at a
measured radius, 22 at a derived one. Every other star's is derived: its temperature off Pecaut & Mamajek's dwarf
sequence at its colour (the same table the spectral estimate reads, or at the colour its type
implies where it has none), its luminosity from its absolute magnitude and the bolometric
correction luminositySolar already applies, and R = sqrt(L) / (T / 5772 K)^2. Against the
archive's own st_rad for the 1 447 catalogue hosts that have one, the derived radius is within
0.018 dex at the median, 0.071 dex at the 90th percentile, and within a factor of 1.5 for
97.1 %. Sirius comes out 1.79 solar radii (1.711 published, Liebert et al. 2005), Wolf 359 0.117,
Betelgeuse 584, the Sun exactly 1.

A star with no band has only the ETL's stand-in magnitude, and gets no derived radius: PSR
J1719-1438 came out 2.3 solar radii from it, wider than its planet's orbit. With the stars that
have neither a colour nor a type, that leaves 3 077 of 455 608 stars (274 of 4 735 hosts) with
no radius; they are drawn at the Sun's, and their card gives none.

The card says which it is: "Radius 0.141 solar radii" for a published one, "~0.10 solar radii,
from colour and brightness" for a derived one, two figures because colour does not give three.

A giant drawn at its size can be wider than its system, so systemFramingDistanceAu also makes
room for the star, and the controls' closest approach is now three of the star's radii where
that is more than the old 0.05 AU. 23 211 stars are drawn wider than 3.6 solar radii, which put
0.05 AU inside three of their radii, and a zoom would have carried the camera through the
surface of the largest. The Sun keeps 0.05 AU. starMarkerRadiusAu and the renderer's innermost
axis, which only it read, are gone.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/app/features/galaxy-system/galaxy-system-scene.component.ts

@@ -40,7 +40,7 @@ import { DeepSkyRenderer } from './deep-sky-renderer';
 import { galacticNormal, PolarGridPlane, TetherField } from './grid-plane';
 import { MilkyWayRenderer } from './milky-way-renderer';
 import {
-  starMarkerRadiusAu,
+  closestApproachAu,
   SUN_RADIUS_AU,
   systemFrameRadiusAu,
   systemFramingDistanceAu,
@@ -55,7 +55,7 @@ import {
   type ScaleBar,
 } from '../../shared/format/scale-bar';
 import { BodyDetailViewModel } from '../body-detail/body-detail.model';
-import { buildBodyViewModel, luminosityOf } from '../body-detail/body-view-model';
+import { buildBodyViewModel, luminosityOf, starSurfaceOf, StarSurface } from '../body-detail/body-view-model';
 import {
   DEFAULT_HUD_DISPLAY,
   HudDisplay,
@@ -284,7 +284,6 @@ const GALACTIC_LEVEL_THRESHOLD = 0.5;
 
 const SYSTEM_NEAR_AU = 0.002;
 const SYSTEM_FAR_AU = 20000;
-const SYSTEM_MIN_DISTANCE_AU = 0.05;
 const SYSTEM_MAX_DISTANCE_AU = 5000;
 /** Where the camera lands (AU) immediately after swapping into system space, pre-settle. */
 const SYSTEM_ENTRY_DISTANCE_AU = 200;
@@ -415,7 +414,7 @@ export class GalaxySystemSceneComponent implements AfterViewInit, OnDestroy {
   private readonly galaxyGroup = new THREE.Group();
   private readonly systemGroup = new THREE.Group();
   private readonly starMarkerMaterial = new THREE.MeshBasicMaterial({ color: 0xffffff });
-  /** Rebuilt per system, since the star's radius is derived from that system's innermost orbit. */
+  /** Rebuilt per system, since every star has its own radius. */
   private starMarkerGeometry?: THREE.SphereGeometry;
 
   /** Readout panel contents, refreshed on the same cadence as the labels rather than per frame. */
@@ -551,6 +550,8 @@ export class GalaxySystemSceneComponent implements AfterViewInit, OnDestroy {
   private currentStarId: number | null = null;
   private systemRenderer?: SystemOrbitsRenderer;
   private starMarker?: THREE.Mesh;
+  /** The system's star's radius and temperature, worked out once on entering it. */
+  private currentStarSurface?: StarSurface;
 
   constructor(
     private readonly engine: EngineService,
@@ -1754,7 +1755,7 @@ export class GalaxySystemSceneComponent implements AfterViewInit, OnDestroy {
           label: 'Bodies',
           value: moonCount > 0 ? `${planetCount} + ${moonCount} moons` : `${planetCount}`,
         },
-        ...starReadouts(star, luminosityOf(star)),
+        ...starReadouts(star, luminosityOf(star), this.currentStarSurface),
       ]);
       this.hudNote.set(this.time.atNow() ? 'Orbits propagated from published elements to the current date.' : 'Orbits propagated from published elements to the date on the clock.');
       this.hudRange.set(
@@ -2203,10 +2204,15 @@ export class GalaxySystemSceneComponent implements AfterViewInit, OnDestroy {
     this.systemGroup.add(this.systemRenderer.object);
     this.applyDisplay(this.display());
 
+    // Every star at its own radius: the archive's for a planet host, otherwise derived from its
+    // colour and brightness — or the Sun's, for the 3 077 stars with no measured magnitude or with
+    // neither a colour nor a type, which the card then gives no radius.
+    this.currentStarSurface = starSurfaceOf(star, systemExoplanets);
+    const starRadiusAu = (this.currentStarSurface.radiusSolar ?? 1) * SUN_RADIUS_AU;
+
     // Framed against the grid's outer ring rather than the outermost orbit — the ring is always
-    // the wider of the two — and against the camera this scene actually has, so the margin holds
-    // whatever the window shape. Computed before the star, because how far away the star will be
-    // seen from is what decides how big its halo has to be to stay visible.
+    // the wider of the two — or against the star, for a giant wider than both; and against the
+    // camera this scene actually has, so the margin holds whatever the window shape.
     // Framed against the perspective camera whichever is active: the framing distance is what
     // the orthographic frustum is then sized from, so both projections show the same extent.
     const framingCamera = this.engine.getPerspectiveCamera();
@@ -2214,14 +2220,8 @@ export class GalaxySystemSceneComponent implements AfterViewInit, OnDestroy {
     const framingDistance = systemFramingDistanceAu(
       this.systemRenderer.gridOuterRadiusAu,
       viewport,
+      starRadiusAu,
     );
-
-    // The Sun at its own radius; every other star sized against its innermost orbit, which is all
-    // the catalogue supports, and which at least never lets it swallow its own planets.
-    const starRadiusAu =
-      star.id === SOL_STAR_ID
-        ? SUN_RADIUS_AU
-        : starMarkerRadiusAu(this.systemRenderer.minTopLevelSemiMajorAxisAu);
     this.starMarkerGeometry?.dispose();
     this.starMarkerGeometry = new THREE.SphereGeometry(starRadiusAu, 64, 32);
 
@@ -2255,7 +2255,7 @@ export class GalaxySystemSceneComponent implements AfterViewInit, OnDestroy {
     depthCamera.near = SYSTEM_NEAR_AU;
     depthCamera.far = SYSTEM_FAR_AU;
     depthCamera.updateProjectionMatrix();
-    this.controls!.minDistance = SYSTEM_MIN_DISTANCE_AU;
+    this.controls!.minDistance = closestApproachAu(starRadiusAu);
     this.controls!.maxDistance = SYSTEM_MAX_DISTANCE_AU;
 
     this.resetZoom();