{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T15:37:55.913Z","years_from_j2000":26.67,"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-197484","name":"HD 197484","class":"g3v_yellow_main_sequence_star","category":"star","object_type":"G3V yellow main-sequence star","mag":8.88,"mag_band":"V","abs_mag":4.897,"abs_mag_band":"V","distance_ly":204.2306436604041,"distance_method":"parallax","ra_deg":311.38527,"dec_deg":-42.950145,"epoch_ra_deg":311.833958,"epoch_dec_deg":-42.854108,"epoch_moved_arcsec":5.638,"pm_ra_mas_yr":-60.86,"pm_dec_mas_yr":-202.44,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Microscopium","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-197484","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"20455-4257","age_years":10699592000,"companions":[{"measured":2021,"magnitude":13.6,"components":"AB","discoverer_code":"GKM9462","separation_arcsec":1.3,"position_angle_deg":200}],"mass_solar":0.926,"radius_solar":1.061,"spectral_type":"G3V","color_index_bv":0.636,"luminosity_solar":0.9576349769692682,"radial_velocity_km_s":21.1,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality C)","surface_gravity_log_g":4.356,"surface_temperature_k":5628,"proper_motion_ra_mas_yr":-60.86,"proper_motion_dec_mas_yr":-202.44,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":1.0082},"designations":[{"catalog":"HD","designation":"HD 197484"},{"catalog":"HIP","designation":"HIP 102446"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}