{
  "schema": "euclid-registered-bulge/v1",
  "preparedAtUTC": "2026-10-16T20:29:55.024Z",
  "source": {
    "hipsUrl": "https://esdchips.esac.esa.int/EuclidOutreach/Q2-EGBS-PNG-RGB_HIPS/",
    "propertiesUrl": "https://esdchips.esac.esa.int/EuclidOutreach/Q2-EGBS-PNG-RGB_HIPS/properties",
    "propertiesSha256": "7a70fadd82533a462c3c95c35f4581811c5ea508ce4479e2820f2f7b210d8bba",
    "mocUrl": "https://esdchips.esac.esa.int/EuclidOutreach/Q2-EGBS-PNG-RGB_HIPS/Moc.fits",
    "mocSha256": "b351c2a5eab71785ceb3fca3b0cb6a1dc88b324a70f5d59e872147f96331dfcc",
    "exportUrl": "https://alasky.cds.unistra.fr/hips-image-services/hips2fits?hips=https%3A%2F%2Fesdchips.esac.esa.int%2FEuclidOutreach%2FQ2-EGBS-PNG-RGB_HIPS%2F&width=2048&height=2048&wcs=%7B%22NAXIS%22%3A2%2C%22NAXIS1%22%3A2048%2C%22NAXIS2%22%3A2048%2C%22WCSAXES%22%3A2%2C%22CRPIX1%22%3A1024.5%2C%22CRPIX2%22%3A1024.5%2C%22CDELT1%22%3A-0.0015629062832914174%2C%22CDELT2%22%3A0.0015629062832914174%2C%22CUNIT1%22%3A%22deg%22%2C%22CUNIT2%22%3A%22deg%22%2C%22CTYPE1%22%3A%22RA---TAN%22%2C%22CTYPE2%22%3A%22DEC--TAN%22%2C%22CRVAL1%22%3A268.237%2C%22CRVAL2%22%3A-29.369%2C%22RADESYS%22%3A%22ICRS%22%7D&format=fits",
    "exportSha256": "9779d22789ff94ff27e85576b4093c59755cf0b2e40e05d7b7b5972e11d4512d",
    "exportBytes": 16781760,
    "exportFormat": "FITS four8-bit RGBA planes",
    "article": "https://www.esa.int/ESA_Multimedia/Images/2026/06/Euclid_s_view_of_our_galaxy_s_bulge",
    "centerReference": "https://www.euclid-ec.org/science/q2/",
    "centerChoice": "Official pointing5; authored cutout center, not claimed survey centroid",
    "observation": "Euclid VIS March2025; CFHT optical colors summer2025",
    "releaseDate": "2026-06-24"
  },
  "credit": "ESA/Euclid/Euclid Consortium/NASA, CFHT, image processing by J.-C. Cuillandre and E. Bertin (CEA Paris-Saclay)",
  "licence": {
    "name": "CC BY-SA3.0IGO",
    "url": "https://creativecommons.org/licenses/by-sa/3.0/igo/",
    "source": "ESA image article explicitly offers this licence",
    "derivativeLicence": "CC BY-SA3.0IGO",
    "modifications": "CDS HiPS reprojection into north-up TAN; FITS row reversal; mobile downsample; WebP encoding. No generated content, recoloring or filling of no-data."
  },
  "exportService": {
    "name": "CDS HiPS2FITS",
    "documentation": "https://alasky.cds.unistra.fr/hips-image-services/hips2fits",
    "acknowledgement": "This image cutout used HiPS2FITS, a service provided by CDS."
  },
  "projection": {
    "name": "TAN/gnomonic",
    "frame": "ICRS",
    "centerRaDegrees": 268.237,
    "centerDecDegrees": -29.369,
    "fieldOfViewDegrees": 3.2,
    "tangentHalfExtent": 0.027932529196587494,
    "orientation": "North up, east left",
    "sourceWcs": {
      "SIMPLE": true,
      "BITPIX": 8,
      "NAXIS": 3,
      "NAXIS1": 2048,
      "NAXIS2": 2048,
      "NAXIS3": 4,
      "WCSAXES": 2,
      "CRPIX1": 1024.5,
      "CRPIX2": 1024.5,
      "CDELT1": -0.0015629062832914,
      "CDELT2": 0.0015629062832914,
      "CUNIT1": "deg",
      "CUNIT2": "deg",
      "CTYPE1": "RA---TAN",
      "CTYPE2": "DEC--TAN",
      "CRVAL1": 268.237,
      "CRVAL2": -29.369,
      "LONPOLE": 180,
      "LATPOLE": -29.369,
      "MJDREF": 0,
      "RADESYS": "ICRS"
    },
    "basis": {
      "center": [
        -0.026811321218405796,
        -0.8710667612800354,
        -0.4904323097509313
      ],
      "east": [
        0.9995266361397517,
        -0.030765299399686453,
        0
      ],
      "north": [
        -0.015088296844767167,
        -0.49020015681959705,
        0.8714792880799673
      ]
    },
    "uvTopDown": "denom=dot(direction,center); u=.5-dot(direction,east)/(denom*2*tangentHalfExtent); v=.5-dot(direction,north)/(denom*2*tangentHalfExtent)",
    "uvTextureLoaderFlipYTrue": "u=.5-dot(direction,east)/(denom*2*tangentHalfExtent); v=.5+dot(direction,north)/(denom*2*tangentHalfExtent)",
    "sampling": "Require denominator>0 and0<=u,v<=1; alpha carries true source no-data. Never repeat/copy the patch elsewhere in the sky."
  },
  "footprint": {
    "surveyAreaDegrees2": 4.8,
    "sourceMocOuterAreaDegrees2": 5.176327164385834,
    "sourceMocCells": 890,
    "sourceMocMaximumOrder": 12,
    "sourceAlphaCoveredPixels": 2081553,
    "sourceAlphaCoveredFraction": 0.4962809085845947,
    "sourceAlphaBoundsTopDownPixels": {
      "left": 324,
      "top": 172,
      "right": 1725,
      "bottom": 1878
    },
    "sourceAlphaRange": [
      0,
      255
    ],
    "outerBorderCoveredPixels": 0,
    "note": "Rectangular TAN extent is not filled survey coverage. Preserve RGBA no-data; dark RGB is not a mask."
  },
  "processing": {
    "software": "sharp 0.35.3",
    "sourcePlanes": "RGBA",
    "northFirstRows": "Reversed FITS south-first rows exactly once",
    "encoding": "WebP quality94, alphaQuality100, effort5",
    "mobileResampling": "Lanczos3,2048 to1024, preserves angular extent",
    "upscaling": false,
    "generatedImagery": false,
    "recoloring": false
  },
  "limitations": [
    "Finite4.8deg² survey, not all-sky wallpaper.",
    "Actual optical multi-instrument color composite, not continuous-spectrum measurement or a live sky feed.",
    "Image display colors are not calibrated flux values.",
    "HiPS initialFOV13500 is ambiguous and unused; returned FITSWCS is the registration contract.",
    "Source MOC is an outer coverage approximation; source alpha provides pixel no-data."
  ],
  "verification": {
    "returnedWcsMatchesRequest": true,
    "sourceRgbaAlphaPreserved": true,
    "transparentOuterMargins": true,
    "gnomonicRoundTripMaximumTolerance": 1e-12
  },
  "assets": [
    {
      "url": "/celestial/fusion-v1/euclid-bulge-2048.webp",
      "width": 2048,
      "height": 2048,
      "bytes": 1470248,
      "sha256": "69e56fd50ca6418e009e587a306f9eea600cb75bed55ab3fa2ef9c423fdabbe1",
      "hasAlpha": true,
      "wcs": {
        "SIMPLE": true,
        "BITPIX": 8,
        "NAXIS": 3,
        "NAXIS1": 2048,
        "NAXIS2": 2048,
        "NAXIS3": 4,
        "WCSAXES": 2,
        "CRPIX1": 1024.5,
        "CRPIX2": 1024.5,
        "CDELT1": -0.0015629062832914,
        "CDELT2": 0.0015629062832914,
        "CUNIT1": "deg",
        "CUNIT2": "deg",
        "CTYPE1": "RA---TAN",
        "CTYPE2": "DEC--TAN",
        "CRVAL1": 268.237,
        "CRVAL2": -29.369,
        "LONPOLE": 180,
        "LATPOLE": -29.369,
        "MJDREF": 0,
        "RADESYS": "ICRS"
      },
      "estimatedRGBA8WithMipsMiB": 21.333333333333332
    },
    {
      "url": "/celestial/fusion-v1/euclid-bulge-1024.webp",
      "width": 1024,
      "height": 1024,
      "bytes": 317614,
      "sha256": "cbcb5f85ae33cbeb96056eb903ac7e40bd4c2f75a08b4c6ef28cd2ecf6858f16",
      "hasAlpha": true,
      "wcs": {
        "SIMPLE": true,
        "BITPIX": 8,
        "NAXIS": 3,
        "NAXIS1": 1024,
        "NAXIS2": 1024,
        "NAXIS3": 4,
        "WCSAXES": 2,
        "CRPIX1": 512.5,
        "CRPIX2": 512.5,
        "CDELT1": -0.0031258125665828,
        "CDELT2": 0.0031258125665828,
        "CUNIT1": "deg",
        "CUNIT2": "deg",
        "CTYPE1": "RA---TAN",
        "CTYPE2": "DEC--TAN",
        "CRVAL1": 268.237,
        "CRVAL2": -29.369,
        "LONPOLE": 180,
        "LATPOLE": -29.369,
        "MJDREF": 0,
        "RADESYS": "ICRS"
      },
      "estimatedRGBA8WithMipsMiB": 5.333333333333333
    }
  ]
}