सूर्य — Solar Ephemeris & Astronomical Observatory
Live apparent Sun · Earth–Sun geometry · seasons · saṅkrānti · equation of time · declination · ayanāṃśa · eclipses — from precise apparent positions (Engine A).
Solar instrument panel
Level 1 · Today's Sun
1 · Live solar observatory data
2 · आज का सूर्य (local)
Level 2 · Astronomical Sun
3 · सूर्य की दैनिक गति (altitude)
4 · Earth–Sun geometry
5 · ऋतु प्रयोगशाला (seasons)
Sāyana (tropical) crossings of λ☉ = 0° / 90° / 180° / 270°. Sidereal (nirayana) marking shown via saṅkrānti in section 7.
6 · Sūryasiddhānta vs modern ayanāṃśa
Sūryasiddhānta (Mool) ayanāṃśa live (ayana-calana/spanda). SS graha sphuṭa अलग SS engine से आता है; यहाँ ayanāṃśa-आधारित तुलना।
Level 3 · Pañcāṅga Sun
7 · Saṅkrānti laboratory
Solar ingress: nirayana λ = 0°,30°,…,330° (Lahiri). Sidereal rāśi boundaries.
8 · Makar Saṅkrānti research
Traditional Uttarāyaṇa begins at Makara saṅkrānti (nirayana λ☉=270°); the astronomical northward motion begins at the December solstice (tropical λ☉=270°). The two differ by the ayanāṃśa.
9 · Equation of time
10 · Solar declination
Level 4 · Scientific Sun
11 · सूर्य का उदय-अस्त observatory
Sunrise/set = upper limb at the visible horizon: geometric centre altitude h₀ = −R − SD − dip (all negative) — R = refraction (≈34′ at P/T), SD = solar semidiameter (≈16′), dip = 1.76′·√h. Sea level ⇒ h₀ ≈ −0.833°. Twilight = geometric centre −6°/−12°/−18°. Alt/P/T editable above.
12 · Solar eclipse laboratory auto-computed
Status
Press “Compute eclipses”.
Local circumstances deepen in the Eclipse page.
13 · Solar motion (reference chain)
14 · Precession / ayanāṃśa laboratory
Level 5 · Deep-time & research Sun
15 · Sun & Pañcāṅga
16 · Engine-B Sun laboratory data
Engine B = independent N-body (DOPRI5; Newtonian+1PN+J2..). Δ relative to DE441/DE440. Sun barycentric.
17 · IC Monte-Carlo offline
18 · Deep-time Sun data · reference region
REFERENCE = DE441 validated (±~15 kyr) · RECONSTRUCTION = propagated (offline for >15 kyr). “Dynamical reconstruction — not modern ephemeris accuracy.”