Fill in the Sun's faint neighbours from Gaia, and fold the Gliese entries they repeat

Gaia's G < 12 cut took a quarter of what lies within 10 pc: the red,
brown and white dwarfs most of the neighbourhood is made of, which the
map only had where Gliese happened to list them. Teegarden's Star was
missing, and with it its three planets' host.

A second query fetches the complement out to 50 pc: G >= 12 or no G,
parallax > 20 mas, with pmra/pmdec so the J2016 -> J2000 propagation
applies. The quality filter was chosen by counting. Parallax over error
> 5 keeps 39 751 of the 39 764 sources that pass the floor, but the Gaia
Catalogue of Nearby Stars (GCNS; Gaia Collaboration, Smart et al. 2021)
rejects 11 752 of them as spurious: median G 20.2, astrometric excess
noise 5.4 mas against 0.15 for the ones it keeps, 6 933 toward the
Galactic centre. So the query joins the GCNS main table (EDR3 astrometry
and source ids, which DR3 carries unchanged) and keeps 28 012 rows; the
error cut stays and costs no GCNS source, brown dwarfs included. The
query has its own row-count floor (28 012) and the row-limit cap, and is
ordered by (phot_g_mean_mag, source_id); a second ETL run reproduced
stars.bin, stars-meta.bin and stars-index.json byte for byte. Its ids
start at 1 050 000 000, clear of the main query's and under 2^30, which
V8 keeps unboxed: numbered from 2 000 000 000 they made the app's boot
task 230 ms longer (medians of five interleaved runs, 1.41 s against
1.18). validateStars now refuses an id outside 0 to 2^30.

The Gliese entries these stars duplicate were not folded: HYG carries
them with positions off by up to a minute of arc and photometric
distances, so they missed the 15" tolerance or failed the distance test.
Their proper motions, which Gliese measured well, give them away:
isSameStar now takes two entries moving within 20 % of each other as one
star up to 60" apart, whatever their distances, brightness still
permitting. Of the 602 Gliese-only rows left without a counterpart, 253
have such a Gaia entry; with every entry shifted a quarter degree, none
does. fetchStars passes HYG's motions only for rows without Hipparcos
astrometry: given them too, 15 Hipparcos stars took a co-moving
companion's Gaia entry and the cross-catalogue pairs under an arcsecond
went from 23 to 35. Of HYG's 1 200 stars fainter than V 12 within 25 pc,
1 024 now sit on a Gaia position (325 before); of the 176 left alone, 43
still have a Gaia entry 3-60" away (218 without the motion rule), some of
them real companions.

Measured on the rebuilt catalogue, against the GCNS (sources with
parallax > 100, 40 and 20 mas):
  within 10 pc  336 -> 372  (GCNS 312; the map adds 60 HYG-only stars)
  within 25 pc  3 652 -> 5 560  (GCNS 5 111)
  within 50 pc  13 702 -> 40 916  (GCNS 40 231)
452 331 stars (+27 214). Proxima, Barnard's Star, Wolf 359, Rigel, Deneb
and Alnilam are all present by name; Teegarden's Star is Gaia DR3
35227046884571776 at 3.83 pc and hosts its three planets. Luhman 16 is
not in Gaia DR3 with a parallax (5353626573555863424 has a two-parameter
solution) and stays absent. 94 more exoplanets find a host (2 071), none
changes host. TRAPPIST-1 is now drawn (Gaia DR3 2635476908753563008,
12.47 pc) but its planets are not yet matched to it.

Merge gate, ceilings unchanged: HYG rows without a Gaia counterpart
12 352 -> 11 554 (ceiling 15 000; 10 886 before the naked-eye stars),
cross-catalogue pairs under an arcsecond 23 -> 23 (ceiling 100). The
gate's comment now accounts for the survivors by magnitude.

gzip -9 sizes against the catalogue before both changes: stars.bin
4 711 922 -> 5 030 741 B, stars-meta.bin 2 576 213 -> 2 784 614 B,
stars-index.json 3 724 855 -> 4 003 584 B (+806 KB, 7.3 %). Boot on the
dev server, five interleaved cold runs: the task that indexes the
catalogue after the data lands, median 1 072 -> 1 182 ms; HUD shown,
median 2 622 -> 2 716 ms. This machine measured 0.82-1.30 s for the
same baseline task today, above audit #25's 627-843 ms. The drawn-star
budget is unchanged.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-09-24 20:35:21 +02:00
co-authored by Claude Opus 5.5
parent c64eea0803
commit 74b93a0428
10 changed files with 163 additions and 33 deletions
+77 -15
View File
@@ -70,6 +70,37 @@ function buildQuery(): string {
].join(' ');
}
/**
* The nearby complement of the query above: every source it leaves out for being fainter than its
* magnitude limit, or for having no G at all, out to 50 pc.
*
* The limit took a quarter of what lies within 10 pc — 84 of the 312 sources the Gaia Catalogue of
* Nearby Stars (GCNS; Gaia Collaboration, Smart et al. 2021, A&A 649, A6) has there, Teegarden's
* Star among them — and 28 012 within 50 pc: the red, brown and white dwarfs most of the Sun's
* neighbourhood is made of, which the map only had where Gliese happened to list them. Further out
* the same band is far too many rows to ship (G 12–13 alone is 188 408 within 250 pc).
*
* Only sources the GCNS keeps. Its classifier rejects 11 752 of the 39 764 that pass this parallax
* floor, and the parallax error the main query filters on would keep all but 13 of them: they are
* spurious parallaxes — median G 20.2 and 5.4 mas of astrometric excess noise, against 0.15 mas for
* the ones it keeps; 6 933 of them toward the crowded Galactic centre. GCNS was built on EDR3,
* whose astrometry and source ids DR3 carries unchanged. The error cut is kept for consistency; it
* costs no GCNS source here, brown dwarfs included.
*/
const NEARBY_DISTANCE_PC = 50;
function buildNearbyQuery(): string {
return [
`select top ${ROW_LIMIT}`,
'g.source_id, g.ra, g.dec, g.pmra, g.pmdec, g.parallax, g.parallax_error, g.phot_g_mean_mag, g.bp_rp',
'from gaiadr3.gaia_source g join external.gaiaedr3_gcns_main_1 n on n.source_id = g.source_id',
`where g.parallax > ${parallaxFloorMas(NEARBY_DISTANCE_PC).toFixed(6)}`,
`and g.parallax_over_error > ${(1 / MAX_PARALLAX_ERROR_RATIO).toFixed(1)}`,
`and (g.phot_g_mean_mag >= ${MAGNITUDE_LIMIT} or g.phot_g_mean_mag is null)`,
'order by g.phot_g_mean_mag asc, g.source_id asc'
].join(' ');
}
/**
* How many rows the query above holds when nothing is overridden: 412 765, and DR3 is a finished
* data release, so that number only moves when the query does. It lives here, under the query, so
@@ -87,6 +118,8 @@ function buildQuery(): string {
* slice on purpose.
*/
const DEFAULT_QUERY_ROWS = 412_765;
/** The same count for the nearby query, which the same truncation would cut from its faint end. */
const DEFAULT_NEARBY_QUERY_ROWS = 28_012;
const MIN_ROW_SHARE = 0.95;
/**
@@ -113,31 +146,54 @@ const UNKNOWN_SPECTRAL_TYPE = 'Unknown';
* the real identifier in the name.
*/
const GAIA_ID_BASE = 1_000_000_000;
/**
* Where the nearby query's ids start: fifty million past the main query's, and under 2^30, the
* largest integer V8 keeps unboxed. The Int32 id column would take up to 2^31, but every id past
* 2^30 is a heap number in the app: starting these at 2 000 000 000 made the boot task that
* indexes the catalogue 230 ms longer (1.41 s against 1.18, medians of five interleaved runs).
*/
const NEARBY_ID_BASE = 1_050_000_000;
export async function fetchGaiaStars(): Promise<StarRecord[]> {
const query = buildQuery();
const url = `${GAIA_TAP_URL}?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=${encodeURIComponent(query)}`;
const unchanged = MAGNITUDE_LIMIT === DEFAULT_MAGNITUDE_LIMIT && ROW_LIMIT === DEFAULT_ROW_LIMIT;
console.log(`Fetching Gaia DR3 (within ${DISTANCE_CUTOFF_PC} pc, G < ${MAGNITUDE_LIMIT}, at most ${ROW_LIMIT} rows)...`);
const rows = await fetchQueryRows(buildQuery(), unchanged && DISTANCE_CUTOFF_PC === DEFAULT_DISTANCE_CUTOFF_PC ? DEFAULT_QUERY_ROWS : undefined);
console.log(`Fetching Gaia DR3's nearby complement (within ${NEARBY_DISTANCE_PC} pc, G >= ${MAGNITUDE_LIMIT} or none, kept by the GCNS)...`);
const nearbyRows = await fetchQueryRows(buildNearbyQuery(), unchanged ? DEFAULT_NEARBY_QUERY_ROWS : undefined);
const stars = [...rowsToStars(rows, GAIA_ID_BASE), ...rowsToStars(nearbyRows, NEARBY_ID_BASE)];
console.log(` kept ${stars.length} Gaia stars (of ${rows.length} + ${nearbyRows.length} rows).`);
return stars;
}
/**
* One query's rows, refused when there are fewer than `expectedRows` — see
* {@link DEFAULT_QUERY_ROWS} — or as many as the row limit.
*/
async function fetchQueryRows(query: string, expectedRows: number | undefined): Promise<Record<string, string>[]> {
const url = `${GAIA_TAP_URL}?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=${encodeURIComponent(query)}`;
// Keyed by the whole request, so a response cached for other columns, another order, or
// another endpoint can never be mistaken for this one — the cache records only that some
// response arrived, not what it answered.
const cacheKey = `gaia-dr3-${createHash('sha1').update(url).digest('hex').slice(0, 8)}.csv`;
const csv = await fetchTextCached(url, cacheKey);
const rows = parseCsvObjects(csv);
const jobsQuery = DISTANCE_CUTOFF_PC === DEFAULT_DISTANCE_CUTOFF_PC && MAGNITUDE_LIMIT === DEFAULT_MAGNITUDE_LIMIT && ROW_LIMIT === DEFAULT_ROW_LIMIT;
if (jobsQuery && rows.length < DEFAULT_QUERY_ROWS * MIN_ROW_SHARE) {
const rows = parseCsvObjects(await fetchTextCached(url, cacheKey));
if (expectedRows !== undefined && rows.length < expectedRows * MIN_ROW_SHARE) {
throw new GaiaAnswerError(
`Gaia returned ${rows.length} rows, not the ~${DEFAULT_QUERY_ROWS} this query holds — the answer was cut short, it was an error page ` +
`served with a 200, or the query was edited without updating DEFAULT_QUERY_ROWS; delete tools/etl/.cache/${cacheKey} once the archive answers properly`
`Gaia returned ${rows.length} rows, not the ~${expectedRows} this query holds — the answer was cut short, it was an error page ` +
`served with a 200, or the query was edited without updating its row count; delete tools/etl/.cache/${cacheKey} once the archive answers properly`
);
}
// Not gated on `jobsQuery` like the floor above it: the only ways to reach this cap are the
// overrides that *widen* the query, and they are exactly when it is worth saying. What it must
// not fire on is a deliberately smaller slice, where filling the limit is the whole point.
// Not gated like the floor above it: the only ways to reach this cap are the overrides that
// *widen* the query, and they are exactly when it is worth saying. What it must not fire on is
// a deliberately smaller slice, where filling the limit is the whole point.
if (ROW_LIMIT >= DEFAULT_ROW_LIMIT && rows.length >= ROW_LIMIT) {
throw new GaiaAnswerError(`Gaia returned the query's own ${ROW_LIMIT}-row limit, so it is the limit deciding what the map holds; raise ETL_GAIA_ROW_LIMIT.`);
}
return rows;
}
/** Places each row at J2000.0, numbering them from `idBase` in the query's own order. */
function rowsToStars(rows: readonly Record<string, string>[], idBase: number): StarRecord[] {
const stars: StarRecord[] = [];
rows.forEach((row, index) => {
@@ -153,22 +209,28 @@ export async function fetchGaiaStars(): Promise<StarRecord[]> {
return;
}
const j2000 = propagateProperMotion(raDeg, decDeg, parseOptionalNumber(row['pmra']) ?? 0, parseOptionalNumber(row['pmdec']) ?? 0, CATALOGUE_EPOCH - GAIA_DR3_EPOCH);
const pmRaMasYr = parseOptionalNumber(row['pmra']);
const pmDecMasYr = parseOptionalNumber(row['pmdec']);
const j2000 = propagateProperMotion(raDeg, decDeg, pmRaMasYr ?? 0, pmDecMasYr ?? 0, CATALOGUE_EPOCH - GAIA_DR3_EPOCH);
const { x, y, z } = raDegDecDistanceToXyz(j2000.raDeg, j2000.decDeg, distancePc);
stars.push({
id: GAIA_ID_BASE + index,
id: idBase + index,
name: `Gaia DR3 ${row['source_id']}`,
x,
y,
z,
// Only the nearby query has sources without a G, 45 of them, and they are given its limit.
// That errs bright: 26 of the 31 that 2MASS measured are at J 12.6–15.7, fainter still in G
// for stars this red, and 5 at J 7–8.
magnitude: parseOptionalNumber(row['phot_g_mean_mag']) ?? MAGNITUDE_LIMIT,
spectralType: UNKNOWN_SPECTRAL_TYPE,
colorIndex: parseOptionalNumber(row['bp_rp']) ?? null,
source: 'gaia'
source: 'gaia',
pmRaMasYr,
pmDecMasYr
});
});
console.log(` kept ${stars.length} Gaia stars (of ${rows.length} rows).`);
return stars;
}