Drop the "..." Hipparcos leaves on a spectral type, which read as the app cutting it short

2 127 stars, Sirius among them, read "Spectral type A0m...", in search rows, route options and
the star card. The mark is Hipparcos's own: every one of the 3 803 HYG rows ending in it has a HIP
number, and the catalogue ends a classification it does not print in full with it. The app
truncated nothing, but the text reads as if it had.

fetchStars now trims a trailing "..." from HYG's spectral types. The dictionary in
stars-index.json goes from 3 056 distinct types to 2 883, and from 598 dotted ones to none. The
names, sources and source indices are unchanged, and so is every other column of stars-meta.bin
bar the type indices. gzip -9 of the index goes from 4 015 865 to 4 015 205 bytes.

build.ts validateStars now fails a catalogue with any type ending in "...". Run with the trim
removed, the ETL failed on 2 127 such types. Two ETL runs from cache wrote identical
stars-meta.bin and stars-index.json.

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

tools/etl/build.ts

@@ -80,6 +80,11 @@ function validateStars(stars: StarRecord[]): void {
     `${withoutError} stars have no distance error (at most ${MAX_STARS_WITHOUT_DISTANCE_ERROR} expected) — the parallax errors are being lost.`
   );
   console.log(`  ${withoutBand} stars with a stand-in magnitude; ${withoutError} distances without a published error.`);
+
+  // Hipparcos's mark on a classification it does not print in full reached the card as "Spectral
+  // type A0m...", for Sirius and 2 126 other stars, which reads as text the app cut short.
+  const dotted = stars.filter((star) => star.spectralType.endsWith('...')).length;
+  assertCondition(dotted === 0, `${dotted} spectral types end in "..." — fetchStars no longer trims Hipparcos's mark from them.`);
 }
 
 /**

tools/etl/fetchStars.ts

@@ -60,6 +60,15 @@ function resolveName(row: Record<string, string>): string {
   return `HYG ${row['id']}`;
 }
 
+/**
+ * HYG's spectral type, without the `...` that 2 127 of the map's stars end in, all of them
+ * Hipparcos stars: the Hipparcos catalogue's mark for a classification it does not print in full
+ * (Sirius is "A0m..."). On the map it read as text the app had cut short.
+ */
+function spectralTypeOf(row: Record<string, string>): string {
+  return (row['spect'] ?? '').replace(/\.\.\.$/, '') || 'Unknown';
+}
+
 /**
  * Downloads the HYG (Hipparcos/Yale/Gliese) stellar database, places each star along its
  * equatorial direction (epoch J2000.0) at the better of its Hipparcos and Gaia distances, keeps
@@ -135,7 +144,7 @@ export async function fetchStars(): Promise<StarRecord[]> {
       z: z * scale,
       magnitude,
       ...(magnitudeV === undefined ? {} : { magnitudeBand: 'V' as const }),
-      spectralType: row['spect'] || 'Unknown',
+      spectralType: spectralTypeOf(row),
       colorIndex: colorIndex ?? null,
       ...(colorIndex === undefined ? {} : { colorSystem: 'B-V' as const }),
       ...(distanceError === undefined ? {} : { distanceError }),