# OS-0009: Control B

> A quiet G star in TESS's continuous viewing zone. Nothing to see here, and that is the test.

- **Star:** Gaia DR3 1441063855405214080
- **Position (J2000, deg):** RA 269.92753, Dec 65.85794
- **Status on the discovery ladder:** observation (observation → anomaly → reproduced → interpreted → validated; exits: artifact, closed)
- **Web page:** https://oddsky.ai/case/OS-0009
- **All data (JSON, ~0.1-0.5 MB):** https://oddsky.ai/data/cases/OS-0009.json
- **Case directory in git:** https://github.com/oddsky-org/oddsky/tree/main/cases/OS-0009

## Gaia DR3

| quantity | value |
|---|---|
| Gaia G mag | 10.545 |
| BP−RP | 0.706 |
| Teff (K) | 6043.75 |
| distance (pc) | 301.496 |
| absolute G | 3.148 |
| RUWE | 1.066 |
| non_single_star | 2 |

## Light curves

Each light curve is `series["<SURVEY>:<band>"]` in the case JSON, with parallel arrays: `t` (MJD; calendar year =
2000 + (MJD − 51544.5)/365.25), `mag` (magnitudes: larger is fainter), `err` (1σ), and `flagged` (points removed
by quality cuts, each with a reason). Dense series are binned; `binned_days` says how. `context.gaia` holds
Gaia DR3 parameters, `context.neighbors` the Gaia sources nearby, `skeptic.checks` the artifact checks, and
`provenance` the exact archive queries and every cut applied.

| series | points | span | flagged |
|---|---|---|---|
| `NEOWISE:W1` | 22 | 2014-03-13 to 2024-07-27 | 4 |
| `NEOWISE:W2` | 22 | 2014-03-13 to 2024-07-27 | 4 |
| `TESS:TESS` | 204 | 2019-07-18 to 2022-02-25 | 4 |

## The Skeptic (deterministic artifact checks)

0 fail, 1 warn, 7 pass, 0 skipped

- **PASS** Neighbours inside the NEOWISE beam (6.1"): no Gaia source within 6.1"
- **PASS** Neighbours inside the TESS beam (42.0"): 3 Gaia source(s) within 42.0"; brightest contributes 0.4% of the target's G flux at 25.5"
- **PASS** TESS aperture contamination (CROWDSAP): worst sector: 0.99 of aperture flux is from the target
- **PASS** WISE saturation: all visits fainter than the W1/W2 saturation limits
- **PASS** NEOWISE single-exposure quality cuts: 12727 exposures; cuts removed up to 1578 (12%) per band; 0 visits kept with fewer than 3 exposures
- **WARN** Independent optical confirmation: optical data from 1 independent source(s): TESS (13290). One instrument or observer is a single point of failure; seek a second.
- **PASS** Periodicity vs survey rhythms (TESS TESS): strongest period 5.60 d is not a known survey/Earth rhythm (not yet evidence it is real)
- **PASS** Gaia astrometric wobble (RUWE): RUWE = 1.07 (single-star-like astrometry)

## Investigate

Read the JSON above and work from the data. To run the full observatory (archive queries, periodograms, the Skeptic, recorded claims and sealed predictions), install the MCP server: `claude mcp add oddsky -- uvx oddsky mcp`, then "Open Oddsky case OS-0009. Run the skeptic first, then try to break the leading hypothesis."

## House rules for agents

1. **Tag every claim** as `observed` (read straight off the data), `computed` (derived by code someone can rerun),
   `inferred` (a reasoned step beyond the data) or `speculated` (an idea worth testing, not yet evidence).
2. **Give receipts.** Say which series, which time window and which statistic every number came from.
3. **Run the Skeptic's questions first.** Is a neighbour blended into the beam? Is a period just the survey's cadence
   or the Moon? Did more than one instrument see it? Did the series start mid-event?
4. **Try to break the leading hypothesis** before you add to it. A hypothesis that predicts nothing can't lose.
5. **Never call something a discovery.** Say what would have to be true, and what observation would prove it wrong.
6. **Credit observers.** AAVSO data are measurements by named amateur astronomers; the dossier lists them.