{
  "schema": "org.spacetrc.stellar-repeat-study",
  "schemaVersion": 1,
  "edition": "9.0.0",
  "status": "archived-data-worked-repeat; no independent specialist review or newdiscovery",
  "question": {
    "tr": "Aynı yıldız adayını farklı kataloglarda ararken gözlem dönemi neden önemlidir?",
    "en": "Why does observation epoch matter when comparing candidate records across catalogues?"
  },
  "selection": "20publishedGaiaDR3sources:parallax_over_error>20,ruwe<1.4,Gbetween8and13,properMotion>300mas/year,declinationbetween−60and60; first20byfixedrandom_index. Existingpublished2MASSneighbours arepreselected; this is not an unbiasedcompleteness/precisionbenchmark.",
  "methods": {
    "id": "uniform-rectilinear-barycentric-v1",
    "epochRange": [
      1990,
      2040
    ],
    "epochUnit": "Julian year; Gaia reference2016.0(TCB)",
    "positionFrame": "ICRS barycentric geometric direction",
    "radialVelocityPolicy": "Use reported Gaia radial velocity when available; otherwise conditional zero radial velocity. Missing RV uncertainty is unquantified, never measured zero.",
    "covariance": "Published Gaia5-parameter covariance with finite-difference2x6Jacobian; RV variance independent when reported. Principal-axis1sigma lengths are not a68percent2Dcoverage region.",
    "excluded": [
      "Annual observer parallax",
      "Solar-system aberration",
      "Light-time/relativistic corrections",
      "Galactic gravitational acceleration",
      "Binary orbital motion",
      "Extinction and Gaia parallax zero-point correction"
    ],
    "tmassEpoch": "Approximate Julian year from reported2MASS JD; UTC/TCB seconds and JD±30s uncertainty are neglected at this educational precision.",
    "crossmatch": "Only the packaged published Gaia2MASS good-neighbourhood candidate list, not a complete cone search. Radius selection is not proof of physical identity."
  },
  "summary": {
    "sources": 20,
    "sourcesWithPublishedCandidates": 19,
    "candidateRows": 19,
    "sourcesWithRV": 19,
    "medianUnpropagatedArcsec": 6.633941681749627,
    "medianPropagatedArcsec": 0.08571366583688678,
    "sourcesWithCandidateWithinOneArcsecBefore": 0,
    "sourcesWithCandidateWithinOneArcsecAfter": 19
  },
  "results": [
    {
      "targetId": "gaia-235383247412615936",
      "gaiaSourceId": "235383247412615936",
      "candidates": 1,
      "unpropagatedNearestArcsec": 12.60690275996368,
      "epochPropagatedNearestArcsec": 0.17390747489872374,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-412783469966211456",
      "gaiaSourceId": "412783469966211456",
      "candidates": 1,
      "unpropagatedNearestArcsec": 5.5359161221625754,
      "epochPropagatedNearestArcsec": 0.05508249954743576,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-605060737664539648",
      "gaiaSourceId": "605060737664539648",
      "candidates": 1,
      "unpropagatedNearestArcsec": 7.29796327253177,
      "epochPropagatedNearestArcsec": 0.2200553141291778,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-681064719453783040",
      "gaiaSourceId": "681064719453783040",
      "candidates": 1,
      "unpropagatedNearestArcsec": 5.548720646236677,
      "epochPropagatedNearestArcsec": 0.09499091663234611,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-1247974392203206656",
      "gaiaSourceId": "1247974392203206656",
      "candidates": 1,
      "unpropagatedNearestArcsec": 9.125787004753526,
      "epochPropagatedNearestArcsec": 0.15631081324547205,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-1991778271640247808",
      "gaiaSourceId": "1991778271640247808",
      "candidates": 1,
      "unpropagatedNearestArcsec": 6.83670040379491,
      "epochPropagatedNearestArcsec": 0.12022740806012992,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-2460983348274381696",
      "gaiaSourceId": "2460983348274381696",
      "candidates": 1,
      "unpropagatedNearestArcsec": 13.215171265461068,
      "epochPropagatedNearestArcsec": 0.26078657324345866,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-2517275388678888960",
      "gaiaSourceId": "2517275388678888960",
      "candidates": 1,
      "unpropagatedNearestArcsec": 6.361109248618207,
      "epochPropagatedNearestArcsec": 0.12512253652866445,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-2597253417806816768",
      "gaiaSourceId": "2597253417806816768",
      "candidates": 1,
      "unpropagatedNearestArcsec": 8.033345263965815,
      "epochPropagatedNearestArcsec": 0.08571366583688678,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-2604898798896278784",
      "gaiaSourceId": "2604898798896278784",
      "candidates": 1,
      "unpropagatedNearestArcsec": 6.633941681749627,
      "epochPropagatedNearestArcsec": 0.10451790973553989,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-2882087849218003712",
      "gaiaSourceId": "2882087849218003712",
      "candidates": 1,
      "unpropagatedNearestArcsec": 4.934737539796556,
      "epochPropagatedNearestArcsec": 0.08562381218439874,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-2948291780795832192",
      "gaiaSourceId": "2948291780795832192",
      "candidates": 1,
      "unpropagatedNearestArcsec": 5.613710836339739,
      "epochPropagatedNearestArcsec": 0.08714183023680848,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-2993676867708999296",
      "gaiaSourceId": "2993676867708999296",
      "candidates": 1,
      "unpropagatedNearestArcsec": 5.875809498441909,
      "epochPropagatedNearestArcsec": 0.025175590920554557,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-3235885299189856384",
      "gaiaSourceId": "3235885299189856384",
      "candidates": 1,
      "unpropagatedNearestArcsec": 18.45022840081713,
      "epochPropagatedNearestArcsec": 0.07741168166564844,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-3373342768264623744",
      "gaiaSourceId": "3373342768264623744",
      "candidates": 1,
      "unpropagatedNearestArcsec": 5.732395574853309,
      "epochPropagatedNearestArcsec": 0.07021418238528869,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-4435581505912978688",
      "gaiaSourceId": "4435581505912978688",
      "candidates": 0,
      "unpropagatedNearestArcsec": null,
      "epochPropagatedNearestArcsec": null,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 0
    },
    {
      "targetId": "gaia-4443110789740420480",
      "gaiaSourceId": "4443110789740420480",
      "candidates": 1,
      "unpropagatedNearestArcsec": 4.841635004105999,
      "epochPropagatedNearestArcsec": 0.07966232609959162,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-4606416269652179328",
      "gaiaSourceId": "4606416269652179328",
      "candidates": 1,
      "unpropagatedNearestArcsec": 10.143691346557432,
      "epochPropagatedNearestArcsec": 0.05360861047056966,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-6137588809508151296",
      "gaiaSourceId": "6137588809508151296",
      "candidates": 1,
      "unpropagatedNearestArcsec": 11.243644434167006,
      "epochPropagatedNearestArcsec": 0.006727506189356899,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    },
    {
      "targetId": "gaia-6181044017297795968",
      "gaiaSourceId": "6181044017297795968",
      "candidates": 1,
      "unpropagatedNearestArcsec": 5.720305750214211,
      "epochPropagatedNearestArcsec": 0.05409768247097641,
      "withinOneArcsecBefore": 0,
      "withinOneArcsecAfter": 1
    }
  ],
  "dataSha256": "623ac0d0e3d1a9a545d23a532aee9b8d3ca4e555bcc11899042258b76634db4f"
}