{"id":20210174,"url":"https://github.com/lancelet/star-stream","last_synced_at":"2026-02-26T15:41:12.429Z","repository":{"id":140794619,"uuid":"187356317","full_name":"lancelet/star-stream","owner":"lancelet","description":"Starfield renderer","archived":false,"fork":false,"pushed_at":"2019-06-26T11:31:54.000Z","size":14326,"stargazers_count":11,"open_issues_count":0,"forks_count":1,"subscribers_count":1,"default_branch":"master","last_synced_at":"2025-04-10T13:41:41.482Z","etag":null,"topics":["astronomy","gaia","gaiadr2","rendering","star"],"latest_commit_sha":null,"homepage":null,"language":"Haskell","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/lancelet.png","metadata":{"files":{"readme":"README.rst","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2019-05-18T12:38:57.000Z","updated_at":"2019-07-28T05:58:35.000Z","dependencies_parsed_at":null,"dependency_job_id":"650816ef-7944-401a-91d7-bd11842a59df","html_url":"https://github.com/lancelet/star-stream","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/lancelet/star-stream","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lancelet%2Fstar-stream","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lancelet%2Fstar-stream/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lancelet%2Fstar-stream/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lancelet%2Fstar-stream/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/lancelet","download_url":"https://codeload.github.com/lancelet/star-stream/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/lancelet%2Fstar-stream/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":261244016,"owners_count":23129640,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["astronomy","gaia","gaiadr2","rendering","star"],"created_at":"2024-11-14T05:46:39.239Z","updated_at":"2026-02-26T15:41:12.418Z","avatar_url":"https://github.com/lancelet.png","language":"Haskell","funding_links":[],"categories":[],"sub_categories":[],"readme":"===========\nstar-stream\n===========\n\n.. image:: https://circleci.com/gh/lancelet/star-stream.svg?style=svg\n    :target: https://circleci.com/gh/lancelet/star-stream\n\nA starfield renderer for the Gaia_ DR2 catalog.\n\n.. code-block:: bash\n\n  git clone --recurse-submodules git@github.com:lancelet/star-stream.git\n  cd star-stream\n  cabal new-build\n  ghcid --command='cabal new-repl'\n\nResults from the Gaia DR2 Star Catalog\n--------------------------------------\n\nThe image below shows an equirectangular, galactic-coordinate\nprojection of all 1.69 billon sources in the Gaia_ DR2 catalog. This\n\"integrated flux\" image was created by reading each of the Gaia source\ncatalog files (compressed CSVs) and adding the contribution of flux\nfrom each source to each pixel it influences. The pixel influences are\ncalculated by multiplying the measured flux in each of the three Gaia\nchannels by a convolution filter (Mitchell-Netravali) centred on each\npixel.\n\nThe amount of data to be processed (~588 GB compressed) is too big to\nfit in memory on the machines running this job (typically a MacBook\nPro or an iMac), so it is streamed in smaller batches, currently\ncorresponding to the original source CSV files. The project name\n(`star-stream`) comes from this necessity to stream the data and\naccumulate the image.\n\nThe output from the flux integration process is a floating-point HDR\nimage, which is tweaked (manually, for now) with a non-linear exposure\nin an image editor.\n\n.. image:: gaia-equirectangular-galactic.jpg\n   :scale: 15 %\n\nThis is only an initial exploration. Improvements planned for\nthe future include:\n\n- Add a galactic coordinate Mollweide projection\n- Adjust filtering ellipse according to the local anisotropy\n  of the projection\n- Bucket the source observations into an acceleration structure\n  for faster rendering of subsets\n- Render temporal offsets for sources with proper motion\n- Correlation of sources with a catalog that contains popular\n  names of stars\n- Etc.\n\nDownloading the Gaia GDR2 Star Catalog\n--------------------------------------\n\nThis project uses the Gaia star catalog as a data source. Gaia_ is a\nspace observatory launched by the European Space Agency (ESA) in 2013.\n\nThe second data release from Gaia, called GDR2, was made public on 25\nApril 2018. It consists of GZipped CSV files, stored on an ESA server,\ncomprising a total of ~588 GB of compressed data.\n\nThe gaia-fetch_ package contains a utility to download these\nfiles. Please note that the download may be a long process. (It took 3\nweeks in Sydney, Australia!)\n\n.. _Gaia: https://en.wikipedia.org/wiki/Gaia_(spacecraft)\n.. _gaia-fetch: gaia-fetch\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flancelet%2Fstar-stream","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Flancelet%2Fstar-stream","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flancelet%2Fstar-stream/lists"}