Source: https://guthlabs.ai/docs/instruments/stellar-parallax-distance/implementation/

instrument implementation / implementation-contract

# Stellar Parallax Distance implementation

A source-bound implementation contract for Stellar Parallax Distance; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t2-029

**Effect**: Computation or source lookup only

## Input and validation requirements

The instrument breaks or becomes hazardous at zero parallax because division is undefined, at very large parallax because the small-angle formula diverges from the finite-angle geometric result, and for negative parallax because signed arithmetic produces an unphysical negative distance unless the input is rejected or specially interpreted.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "parallax": 0.1,
    "parallax_unit": "arcsec"
  },
  "expected_outputs": {
    "distance_pc": 10,
    "distance_ly": 32.6156,
    "distance_AU": 2062648.06247
  },
  "working": "1) d(pc)=1/0.1=10 pc. 2) d(ly)=10×3.26156=32.6156 ly. 3) d(AU)=10×206264.806247=2062648.06247 AU."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/stellar-parallax-distance/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/stellar-parallax-distance/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/stellar-parallax-distance/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche2/tranche2-results.json`