{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T17:06:10.118Z","years_from_j2000":26.678,"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-154587","name":"HD 154587","class":"f3v_yellow_white_main_sequence_star","category":"star","object_type":"F3V yellow-white main-sequence star","mag":8.89,"mag_band":"V","abs_mag":2.047,"abs_mag_band":"V","distance_ly":762.0477425599074,"distance_method":"parallax","ra_deg":256.8912,"dec_deg":-30.593854,"epoch_ra_deg":257.321134,"epoch_dec_deg":-30.62968,"epoch_moved_arcsec":0.979,"pm_ra_mas_yr":-20.44,"pm_dec_mas_yr":-30.49,"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-154587","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"17076-3036","age_years":1466518800,"companions":[{"measured":1992,"magnitude":9.98,"components":null,"discoverer_code":"B   329","separation_arcsec":0.2,"position_angle_deg":183}],"mass_solar":1.828,"radius_solar":3.847,"spectral_type":"F3V","color_index_bv":0.551,"luminosity_solar":13.21904253441724,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality C)","surface_gravity_log_g":3.422,"surface_temperature_k":6089,"proper_motion_ra_mas_yr":-20.44,"proper_motion_dec_mas_yr":-30.49,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":15.9221},"designations":[{"catalog":"HD","designation":"HD 154587"},{"catalog":"HIP","designation":"HIP 83798"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T19:50:56.720Z","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."}