{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T23:06:06.166Z","years_from_j2000":26.654,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued J2000 position is carried along the great circle the object's own published motion puts it on, at a constant velocity, 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. 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-4673","name":"HD 4673","class":"a5_white_star","category":"star","object_type":"A5 white star","mag":8.11,"mag_band":"V","abs_mag":2.912,"abs_mag_band":"V","distance_ly":357.2358189493719,"distance_method":"parallax","ra_deg":12.42849,"dec_deg":65.082776,"epoch_ra_deg":12.838867,"epoch_dec_deg":65.229032,"epoch_moved_arcsec":1.111,"pm_ra_mas_yr":40.36,"pm_dec_mas_yr":-10.34,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cassiopeia","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-4673","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"A5","color_index_bv":0.312,"luminosity_solar":5.959365192559373,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","proper_motion_ra_mas_yr":40.36,"proper_motion_dec_mas_yr":-10.34},"designations":[{"catalog":"HD","designation":"HD 4673"},{"catalog":"HIP","designation":"HIP 3873"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","attribution":"Data from SpaceCatalog.org. Individual records carry their source and license in `source`; attribution is required for CC-BY and CC-BY-SA rows."}