{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.847","julian_year":2026.847,"time":"2026-11-06T09:08:37.234Z","years_from_j2000":26.847,"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":"hd-200927","name":"HD 200927","class":"b6v_blue_white_main_sequence_star","category":"star","object_type":"B6V blue-white main-sequence star","mag":8.05,"mag_band":"V","abs_mag":-1.128,"abs_mag_band":"V","distance_ly":2233.9477702409567,"distance_method":"parallax","ra_deg":316.18090099217306,"dec_deg":49.028888,"epoch_ra_deg":316.405257,"epoch_dec_deg":49.136049,"epoch_moved_arcsec":0.202,"pm_ra_mas_yr":-3.14,"pm_dec_mas_yr":-6.85,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cygnus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-200927","source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0","attribution":"HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). 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":{"wds_id":"21047+4902","companions":[{"measured":2014,"magnitude":9.1,"components":null,"discoverer_code":"HU  590","separation_arcsec":0.1,"position_angle_deg":91}],"spectral_type":"B6V","uncertainties":{"distance_ly":[688.1829692783327,1792.6741545398547]},"color_index_bv":0.13,"luminosity_solar":246.15009062337666,"radial_velocity_km_s":2,"spectral_type_source":"SIMBAD (quality C)","proper_motion_ra_mas_yr":-3.14,"proper_motion_dec_mas_yr":-6.85},"designations":[{"catalog":"HD","designation":"HD 200927"},{"catalog":"HIP","designation":"HIP 104044"}],"updated_at":"2026-11-04T19:31:31.075Z","citation":{"plain":"SpaceCatalog. HD 200927 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-200927","bibtex":"@misc{spacecatalog_hd-200927,\n  author       = {{SpaceCatalog}},\n  title        = {{HD 200927}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-200927},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-200927","release":"DR1","doi":null},"references":[],"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."}