{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.808","julian_year":2026.808,"time":"2026-10-23T03:20:54.338Z","years_from_j2000":26.808,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued position is carried along the great circle the object's own published motion puts it on, at a constant velocity, from the epoch that position was measured at, and the result is referred to the true equator and equinox of this instant. Those are separate things: the motion moves the object, and the rotation turns the grid under it by about fifty arcseconds a year, with nutation adding up to another seventeen.","excluded":"Parallax, the radial-velocity perspective term, aberration and refraction; each is below the accuracy of the catalogued positions themselves. An object with no published proper motion comes back where the catalogue has it rather than at a fabricated zero, and says so with a null pm_ra_mas_yr. The motion runs from position_epoch_jyear where the upstream publishes one — a timed pulsar's position belongs to the year it was timed — and from J2000 where it does not. A body with no fixed position is not propagated at all — its place comes from an ephemeris, which is what /api/v1/visible answers with."},"slug":"ngc-4852","name":"NGC 4852","class":"open_cluster","category":"cluster","object_type":"Open cluster","mag":8.9,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":4038.8993931519435,"distance_method":"Gaia DR3 cluster membership (Hunt & Reffert 2024)","ra_deg":195.01829166666667,"dec_deg":-59.60944444444445,"epoch_ra_deg":195.427558,"epoch_dec_deg":-59.754889,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Centaurus","discovered":"1826","featured":false,"url":"https://spacecatalog.org/object/ngc-4852","source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0","attribution":"OpenNGC, Mattia Verga (github.com/mattiaverga/OpenNGC). Fields derived from it stay under CC BY-SA 4.0.","commercial_use":"allowed"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"v_mag":8.9,"redshift":-0.000017,"wikidata_id":"Q1114934","discovered_by":"James Dunlop","ngc_type_code":"OCl","uncertainties":{"distance_ly":[7.534806353867281,7.5630248818174035]},"major_axis_arcmin":5.4,"distance_reference":"NGC 4852","radial_velocity_km_s":-5},"designations":[{"catalog":"IAU cluster","designation":"C 1257-593"},{"catalog":"MWSC","designation":"MWSC 2078"},{"catalog":"NGC","designation":"NGC 4852"}],"updated_at":"2026-10-01T09:42:28.932Z","citation":{"plain":"SpaceCatalog. NGC 4852 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/ngc-4852","bibtex":"@misc{spacecatalog_ngc-4852,\n  author       = {{SpaceCatalog}},\n  title        = {{NGC 4852}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/ngc-4852},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from OpenNGC.}\n}","url":"https://spacecatalog.org/object/ngc-4852","release":"DR1","doi":null},"references":[{"bibcode":"2024A&A...686A..42H","ads_url":"https://ui.adsabs.harvard.edu/abs/2024A%26A...686A..42H/abstract","quantity":"distance_method"}],"attribution":"Data from SpaceCatalog.org. Each record names its upstream in `source`, with that producer's terms in `source.license`, the acknowledgement it asks for in `source.attribution`, and whether its terms allow commercial use in `source.commercial_use`; those terms govern the record, and citing SpaceCatalog does not discharge them."}