{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T09:24:13.559Z","years_from_j2000":26.683,"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-197921","name":"HD 197921","class":"k3v_orange_dwarf","category":"star","object_type":"K3V orange dwarf","mag":9.25,"mag_band":"V","abs_mag":6.232,"abs_mag_band":"V","distance_ly":130.93384705249807,"distance_method":"parallax","ra_deg":312.292155,"dec_deg":-54.777739,"epoch_ra_deg":312.79679,"epoch_dec_deg":-54.680365,"epoch_moved_arcsec":8.939,"pm_ra_mas_yr":184.57,"pm_dec_mas_yr":-279.58,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Indus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-197921","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"20492-5447","companions":[{"measured":2016,"magnitude":15.95,"components":null,"discoverer_code":"NSN 451","separation_arcsec":23.4,"position_angle_deg":17}],"radius_solar":0.855,"spectral_type":"K3V","uncertainties":{"metallicity_fe_h":[0.052,0.052]},"color_index_bv":0.979,"luminosity_solar":0.2800270595010633,"metallicity_fe_h":0.22,"radial_velocity_km_s":-40,"spectral_type_source":"SIMBAD (1975MSS...C01....0H, quality C)","surface_gravity_log_g":4.507,"surface_temperature_k":4766,"metallicity_fe_h_source":"Median of 3 spectroscopic determinations in 4 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":184.57,"proper_motion_dec_mas_yr":-279.58,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.3408},"designations":[{"catalog":"HD","designation":"HD 197921"},{"catalog":"HIP","designation":"HIP 102753"}],"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."}