Find the hosts the catalogue already holds, and name them after their planets' star

The archive's default-parameter rows leave sy_dist blank for 100 planets, TRAPPIST-1's seven
among them, so the matcher could not place a host the catalogue had drawn since the Gaia
nearby query (Gaia DR3 2635476908753563008, 12.47 pc). fetchExoplanets now also reads the
Planetary Systems Composite table (pscomppars) and fills a default row's blank host cells from
it. Only host columns: a composite row takes each column from its own reference, so orbits
still come from the default row alone, one fit per planet. Where both tables give a distance or
a position they agree on all 6 225 and 6 352 rows.

Three hosts the catalogue holds by name failed the distance ratio test because the archive's
sy_dist, from TICv8, contradicts its own parallax: Lalande 21185 (GJ 411) 5.68 pc against
392 mas, Luyten's Star (GJ 273) 5.92 against 263 mas, Struve 2398 B (Gl 725 B) 6.84 against
285 mas. resolveHostStarId now takes the archive's parallax (sy_plx) as a second distance the
ratio test accepts. It is a second chance, not a replacement: 47 of 5 959 systems disagree past
the tolerance, and for faint far hosts the inverse parallax is the worse figure (K2-238: 538 pc
by sy_dist, 6 779 by parallax).

Planets on a catalogue star: 2 071 -> 2 090 of 6 354. The 19 gained are TRAPPIST-1 (7),
GJ 273 (2), GJ 411 (2), Gl 725 B, HD 62509 (Pollux), K2-65, TOI-2267 A and B, and two
brown-dwarf hosts, 2MASS J02192210-3925225 and DENIS-P J082303.1-491201. No planet lost or
changed its host.

A matched host whose catalogue name is a bare Gaia designation now takes the archive's host
name, so search finds TRAPPIST-1, Teegarden's Star, TOI-700, LP 791-18 and K2-18: 575 stars
renamed. validateExoplanets refuses a host that is still only a designation, and the star
assets are rewritten after the exoplanets for that reason; stars.bin and stars-meta.bin are
unchanged. TOI-2267 A and B both land on one Gaia entry, which takes the name TOI-2267 A.

Each planet also carries its host's radius, effective temperature and luminosity (10^st_lum),
and a mass for 6 344 planets instead of 5 474, from the default row where it gives one and the
composite table otherwise, for the star-physics step.

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

tools/etl/build.ts

@@ -7,7 +7,7 @@ import { StarRecord, SUN_STAR_ID } from '../../src/app/shared/models/star.model'
 import { fetchDeepSky } from './fetchDeepSky';
 import { fetchExoplanets } from './fetchExoplanets';
 import { fetchSolarSystem } from './fetchSolarSystem';
-import { BYTES_PER_STAR_META, BYTES_PER_STAR_POSITION, decodeStarCatalog, encodeStarCatalog } from '../../src/app/shared/models/star-catalog';
+import { BYTES_PER_STAR_META, BYTES_PER_STAR_POSITION, decodeStarCatalog, encodeStarCatalog, isDesignation } from '../../src/app/shared/models/star-catalog';
 import { fetchStars } from './fetchStars';
 import { describeSources } from './sources/registry';
 import { dataPath } from './lib/paths';
@@ -155,14 +155,19 @@ function validateBodies(bodies: BodyRecord[]): void {
   assertCondition(planetCount === 8, `Expected 8 planets, found ${planetCount}.`);
 }
 
-function validateExoplanets(exoplanets: ExoplanetRecord[], starIds: Set<number>): void {
+function validateExoplanets(exoplanets: ExoplanetRecord[], stars: StarRecord[]): void {
   assertCondition(exoplanets.length > 0, 'No exoplanets were produced.');
+  const starsById = new Map(stars.map((star) => [star.id, star]));
 
   let crossReferenced = 0;
   for (const exoplanet of exoplanets) {
     assertCondition(!!exoplanet.name, `Exoplanet ${exoplanet.id} has no name.`);
     if (exoplanet.hostStarId !== null) {
-      assertCondition(starIds.has(exoplanet.hostStarId), `Exoplanet ${exoplanet.id} references unknown star id ${exoplanet.hostStarId}.`);
+      const host = starsById.get(exoplanet.hostStarId);
+      assertCondition(host !== undefined, `Exoplanet ${exoplanet.id} references unknown star id ${exoplanet.hostStarId}.`);
+      // A host known only as "Gaia DR3 2635476908753563008" cannot be found by searching for
+      // TRAPPIST-1; fetchExoplanets names it after its host, and 575 were renamed.
+      assertCondition(!isDesignation(host!), `Exoplanet ${exoplanet.id}'s host is only a designation, ${host!.name}, not named after ${exoplanet.hostStarName}.`);
       // The Sun has no exoplanets, so any match to it is a matching failure — historically a
       // blank distance column parsing as 0, which puts the host at the origin and matches Sol
       // exactly. Free, permanent tripwire for that whole class of bug.
@@ -183,7 +188,7 @@ function validateExoplanets(exoplanets: ExoplanetRecord[], starIds: Set<number>)
     );
   }
 
-  console.log(`  ${crossReferenced}/${exoplanets.length} exoplanets cross-referenced to a HYG host star.`);
+  console.log(`  ${crossReferenced}/${exoplanets.length} exoplanets have a host star on the map.`);
 
   // How many can be propagated at their real rate rather than as if the host were the Sun.
   const withPeriod = exoplanets.filter((exoplanet) => exoplanet.periodDays !== undefined).length;
@@ -257,11 +262,12 @@ async function build(): Promise<void> {
   console.log(describeSources());
   console.log();
 
-  const stars = await fetchStars();
+  const catalogueStars = await fetchStars();
   console.log();
   const bodies = await fetchSolarSystem();
   console.log();
-  const exoplanets = await fetchExoplanets(stars);
+  // Names the Gaia designations that host planets, so it is this list, not the one above, that is published.
+  const { exoplanets, stars } = await fetchExoplanets(catalogueStars);
   console.log();
   const deepSky = await fetchDeepSky();
   console.log();
@@ -270,7 +276,7 @@ async function build(): Promise<void> {
   validateStars(stars);
   validateMerge(stars);
   validateBodies(bodies);
-  validateExoplanets(exoplanets, new Set(stars.map((star) => star.id)));
+  validateExoplanets(exoplanets, stars);
   validateDeepSky(deepSky);
 
   console.log('\nETL completed successfully:');