{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.664","julian_year":2026.664,"time":"2026-08-31T13:06:35.971Z","years_from_j2000":26.664,"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-150331","name":"HD 150331","class":"g0_2ii_yellow_bright_giant","category":"star","object_type":"G0/2II yellow bright giant","mag":5.84,"mag_band":"V","abs_mag":1.145,"abs_mag_band":"V","distance_ly":283.36792252408384,"distance_method":"parallax","ra_deg":250.439415,"dec_deg":-33.145759,"epoch_ra_deg":250.874541,"epoch_dec_deg":-33.197876,"epoch_moved_arcsec":2.181,"pm_ra_mas_yr":-58.83,"pm_dec_mas_yr":-56.81,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Scorpius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-150331","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":888980500,"mass_solar":2.178,"radius_solar":5.05,"spectral_type":"G0/2II","color_index_bv":0.653,"luminosity_solar":30.338911841942704,"radial_velocity_km_s":-8,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality D)","surface_gravity_log_g":3.289,"surface_temperature_k":5986,"proper_motion_ra_mas_yr":-58.83,"proper_motion_dec_mas_yr":-56.81,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":29.4342},"designations":[{"catalog":"HD","designation":"HD 150331"},{"catalog":"HIP","designation":"HIP 81741"},{"catalog":"HR","designation":"HR 6192"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}