48319c3fe2a8c266890b51274b233c79acfe2e01
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Commits
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  SenrokaiandClaude Opus 5.5
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48319c3fe2 |
Move the solar system on JPL's mean elements, so it stays right as the clock runs
Every body carried one set of osculating elements from Horizons at 2025-01-01, run forward by
Kepler with a GM from a table of mass ratios. That set is exact at its instant and drifts from
then on, and the clock now runs a month a second: the Moon, with Earth's mass ratio lacking its
own and the osculating axis, went round in 27.70 days instead of 27.32, 66 degrees out after a
year, and its locked face was spun at the same wrong rate.
Planets and Pluto now take Standish's Table 2a/2b ("Keplerian Elements for Approximate
Positions of the Major Planets"): elements against the J2000 ecliptic, their rates per century,
and the b, c, s, f terms of Jupiter to Pluto, fit for 3000 BC to AD 3000. Table 1 is closer near
the present (Saturn 0.23 degrees at worst 1950-2100, against 0.32 here) but is only fit for
1800-2050, and by AD 3000 has Saturn 4.3 degrees out where Table 2 holds every planet within 0.3.
The moons take JPL SSD's satellite mean elements: sidereal mean motion n to ten figures, the
periods of their node and periapsis, and each one's local Laplace plane by its pole. They
propagate with n itself, never a GM: gmForParent and its mass table are gone. Horizons still
gives size, spin and obliquity.
Both tables are read from the Internet Archive's copy of JPL's pages, pinned to one capture: the
live approx_pos page has dropped Pluto, and the live sats/elem page has dropped n and rounds the
period to four or five figures (Phobos 0.3187 d, a revolution out within a decade).
What the tables leave implicit, measured against Horizons before it was accepted:
- The precession periods are magnitudes. A node regresses on a prograde orbit and advances on a
retrograde one; a periapsis advances except where a resonance forces the eccentricity. Io's
and Europa's follow their conjunction line backwards at 2 n(Europa) - n(Io) = 0.74 degrees a
day, which is exactly the 1.625- and 1.394-year periods in the table. Read as advancing, Io
was 0.9 degrees out and Europa 2.1.
- On a retrograde orbit the node's turning is added back to the mean anomaly. Taken off, Triton
drifted a degree a year, 105 degrees by 2100.
- The Laplace frame's x axis is where the plane rises through the ICRF equator, RA of the pole
plus 90. Read against the ecliptic, Io was 2.8 degrees out, Phobos 54 and Titan 127.
Orbit lines are now drawn in their own plane and turned by a quaternion each tick, so a turning
node carries the line with the body: fixed at one date, the Moon's line would be up to 69 000 km
off it nine years on. The Earth row is the Earth-Moon barycentre, 4 700 km from Earth, 0.002
degrees from the Sun. A tidally locked moon's day is now 360 / n, its sidereal period (the Moon
27.321662 d), so it stays locked to the orbit it is drawn on.
Angular error against Horizons VECTORS (ICRF, TDB; heliocentric for planets, planet-centred for
moons), degrees, read from the live renderer's markers in the running app:
body 1950-01-01 1975-01-01 1987-07-23 2000-01-01 2025-01-01 2037-03-06 2050-01-01 2075-01-01 2100-01-01 max
mercury 0.004 0.002 0.003 0.002 0.002 0.001 0.000 0.002 0.000 0.004
venus 0.003 0.007 0.003 0.004 0.004 0.004 0.003 0.004 0.004 0.007
earth 0.003 0.008 0.002 0.005 0.004 0.009 0.003 0.002 0.003 0.009
mars 0.009 0.010 0.008 0.024 0.009 0.012 0.009 0.011 0.028 0.028
jupiter 0.063 0.030 0.171 0.135 0.013 0.020 0.056 0.041 0.075 0.171
saturn 0.080 0.064 0.018 0.320 0.066 0.114 0.044 0.164 0.177 0.320
uranus 0.018 0.169 0.068 0.050 0.101 0.015 0.141 0.017 0.114 0.169
neptune 0.070 0.028 0.004 0.021 0.036 0.037 0.013 0.029 0.072 0.072
pluto 0.045 0.054 0.041 0.033 0.019 0.020 0.023 0.027 0.026 0.054
moon 0.486 1.928 0.127 0.631 1.407 1.086 0.720 0.339 1.180 1.928
phobos 2.068 0.294 0.881 1.113 0.313 0.636 2.089 5.862 11.099 11.099
deimos 0.077 0.043 0.310 0.066 0.164 0.068 0.034 0.468 0.044 0.468
io 0.021 0.015 0.010 0.019 0.009 0.035 0.006 0.011 0.022 0.035
europa 0.036 0.039 0.053 0.064 0.078 0.032 0.006 0.034 0.044 0.078
ganymede 0.132 0.103 0.018 0.007 0.023 0.054 0.091 0.118 0.044 0.132
callisto 0.040 0.019 0.023 0.019 0.038 0.008 0.060 0.119 0.056 0.119
titan 0.003 0.019 0.023 0.023 0.027 0.028 0.048 0.008 0.014 0.048
triton 0.051 0.029 0.009 0.021 0.052 0.048 0.063 0.089 0.137 0.137
Three miss what was hoped for, and why:
- Jupiter 0.17, Saturn 0.32, Uranus 0.17 against the 0.1 hoped for: short-period perturbations
of the giants by one another, which no Keplerian fit carries. Standish states his own Table 2
errors as 600, 1 000 and 2 000 arcseconds (0.17, 0.28, 0.56 degrees). Out to AD 3000, measured
at 1800, 2200, 2400, 2600 and 3000, every planet stays within 0.3.
- The Moon, 1.9: evection (1.27) and variation (0.66), which a mean ellipse leaves out.
- Phobos, 2.1 until 2050, then 5.9 in 2075 and 11.1 in 2100, growing as the square of the time:
its tidal acceleration, which the table has no column for. Its elements are MAR080's, epoch
1950. The map's dates are also UTC where the elements are TDB, 69 s today,
which is 0.9 degrees of Phobos and nothing for anything else.
Held in place by:
- build.ts: each body's mean elements against Horizons' own osculating elements on the ETL's
2025-01-01, at most 0.25 degrees for a planet and 2.5 for a moon (measured: Uranus 0.101, the
Moon 1.407; a regressing Triton node reads 10.24 and fails), and every moon's day equal to its
sidereal period (a 1% error fails).
- Unit tests freezing nine Horizons vectors (Earth 2100, Jupiter 1950, Saturn 2075, Pluto 1975,
the Moon 2050, Io and Europa 1950, Titan and Triton 2100) through SystemOrbitsRenderer, the
Moon kept on its own turning line, the retrograde rule, the Standish terms, the Laplace frame,
and both table parsers. Nine mutants each fail the test named for them, and the two
validators each refuse a mutated build of the real catalogue.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
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SenrokaiandClaude Fable 5
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08534279fb |
Bring Gaia to HYG's epoch before merging, and keep a star's name when it matches
Gaia DR3 gives positions for J2016.0, HYG for 2000.0, and the merge matched them on the sky to one arcsecond without propagating any proper motion. Sixteen years of motion is 62" for Proxima and 166" for Barnard's Star, so every star faster than ~62 mas/yr — most of the nearest ones — was kept twice, some 23 000 in all. The slow ones were matched, and lost: the merge kept Gaia's row whole, so 102 proper names, 1 336 Bayer/Flamsteed names and 32 000 spectral types became "Gaia DR3 <id>" and "Unknown", and 92 named exoplanet hosts handed their planets to their anonymous twin. Gaia is now asked for its proper motions and carried back to J2000 before it leaves the fetcher. HYG is placed from its own x/y/z columns, which are right where its `ra` is not: that column was carried from the Hipparcos epoch without the cos δ its motion needs, 17.9" off for Proxima. A match combines the two entries — Gaia's position, HYG's name, type, magnitude, colour and id — instead of choosing one. The tolerance is 15" with a five-magnitude guard, both set by measurement: 55 457 pairs sit under 1" once the epochs agree, the Gliese-only entries up to 12" (Ross 248), shifting every entry a quarter of a degree finds 16 chance neighbours at 15", and the guard keeps Sirius out of Sirius B's entry. Entries of one source are never merged with each other: the 1 411 Gaia doubles resolved under 1" are two stars, not one. Regenerated: 425 071 stars (was 447 410), 56 082 of them Gaia positions carrying HYG identities; no HYG id or name lost; the sixteen stars nearest the Sun carry no survey designation; 196 residual doubles, all components 17" or more from their counterpart. Five planets of four bright giants (7 CMa, HD 81688, omi UMa, xi Aql) lose their host link: their Gaia distance sits 0.7–1.1 pc from the archive's Hipparcos-based one, past the 0.5 pc the host match allows. Matching hosts on the sky rather than in space, as the merge does, is the follow-up. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QL6F9Bgfh8SgAiAAcPB9Hw |
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Claude
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2293585940 |
Put orbits and stars in the same reference frame
The app's two sources disagree about which frame they are in, and nothing reconciled them. HYG star positions are equatorial J2000 — that is what raDecDistanceToXyz produces and what the galaxy view renders directly. Orbital elements come from JPL Horizons, whose default reference plane for element output is the ecliptic, and the ETL never overrides it. The two are tilted 23.4 degrees apart, so the orbits sat that far off the sky they are drawn against. Confirmed rather than assumed, from both ends: the Horizons request in lib/horizons.ts sets no REF_PLANE, and the resulting solar-system inclinations are 0 to 17 degrees with Earth exactly 0.00 — which is only true of the ecliptic, since Earth's orbit defines it. eclipticToEquatorial now rotates orbit positions into the scene frame, so a direction means the same thing in the galaxy view and the system view. The rotation is about the vernal-equinox axis, which both frames share. That exposed a presentation problem the old code had been hiding. The renderer mapped the propagator's z straight onto the scene's vertical, which silently redefined the frame but did make systems render flat. In a properly equatorial scene, orbital planes lie 23.4 degrees off the scene's own axes, so a system would be presented edge-on. Rather than rotate the world back into a comfortable pose — which would only put the orbits at odds with the sky again — the camera now settles relative to the orbital plane: a three-quarter view about 37 degrees off the ecliptic normal. The arrival still begins along the approach direction and swings round as it settles, so the transition stays continuous, and the framing is now the same every time rather than inherited from wherever the camera happened to be. Tests: 247 passing, up from 237. The frame tests are the discriminating kind — Earth's orbit must lie perpendicular to the ecliptic pole rather than to the scene's vertical, and must reach 23.4 degrees of declination a quarter orbit on, where it used to read zero. Verified in a browser against Sol and Gl 357. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WaySiNst4HhDXBHnMy8p5G |
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Claude
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3a859360ba |
Add the deep-sky backdrop, the last unbuilt piece of the plan
The design doc scopes deep-sky objects as a galaxy-view backdrop and lists fetchDeepSky.ts, deepsky.json and deepsky.model.ts, but none of it existed — it was the only part of the plan with no implementation behind it. ETL: fetchDeepSky.ts pulls the OpenNGC catalog, classifies each object as a galaxy/nebula/cluster, and keeps the ~460 worth drawing (everything Messier, everything with a common name, and anything brighter than magnitude 9) out of ~12,000 mostly-anonymous rows. build.ts runs it and validates the output. Distances are the hard part: OpenNGC has no distance column, and both fallbacks fail for the best-known objects. M31, M33 and M42 are Local Group members whose redshift is negative or absent, and a galaxy's catalog parallax comes from a cross-matched foreground star — 6 mas for M31 would put a 780 kpc galaxy at 167 pc. So records store a unit direction on the celestial sphere rather than a position (the line of sight is always known precisely, and the objects are drawn on a fixed backdrop shell where true distance is unusable anyway), and distance is optional metadata carrying its own provenance. Parallax is trusted only for galactic objects, redshift only above z=0.003 where expansion outweighs peculiar velocity. 330 of 463 get a distance; the rest honestly report none. Rendering: DeepSkyRenderer paints the objects as soft additive billboards on a 2500 pc shell — clear of the 50 pc star field, beyond the camera's 2000 pc orbit limit, and inside its 5000 pc far plane. Size comes from real angular extent, so Andromeda is six times wider than the full Moon, clamped at both ends. Sprites rather than points because the WebGPU backend caps point primitives at one pixel; materials are shared per kind and brightness band, so 460 objects cost nine of them. The brightest dozen get permanent labels, which needed the label overlay to accept string ids alongside numeric star ids. The backdrop is decorative, so a failure to load its dataset is logged and the star field comes up regardless. Also documents the app in the README, which until now covered only the plugin marketplace. Tests: 112 passing, up from 54. Build, both typechecks and the Playwright suite are green. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WaySiNst4HhDXBHnMy8p5G |
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Senrokai
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d7e8ea1d4d |
@
Add star-map Angular app, ETL pipeline, and caveman plugin Angular 3D star map (galaxy/system/body views, Three.js rendering, navigation store) plus the NASA ETL tooling that builds the star, exoplanet and solar-system datasets, Playwright e2e suite, and the cs:caveman Claude Code plugin (command, agent, skill). Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> @ |