{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T08:15:49.937Z","years_from_j2000":26.669,"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-21680","name":"HD 21680","class":"f6v_yellow_white_main_sequence_star","category":"star","object_type":"F6V yellow-white main-sequence star","mag":9.11,"mag_band":"V","abs_mag":-0.175,"abs_mag_band":"V","distance_ly":2346.448889606793,"distance_method":"parallax","ra_deg":52.18056,"dec_deg":-33.207504,"epoch_ra_deg":52.447967,"epoch_dec_deg":-33.114552,"epoch_moved_arcsec":1.136,"pm_ra_mas_yr":-25.97,"pm_dec_mas_yr":-33.77,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Fornax","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-21680","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":2246582500,"mass_solar":1.535,"radius_solar":2.427,"spectral_type":"F6V","color_index_bv":0.525,"luminosity_solar":102.32929922807536,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1982MSS...C03....0H, quality C)","surface_gravity_log_g":3.816,"surface_temperature_k":6297,"proper_motion_ra_mas_yr":-25.97,"proper_motion_dec_mas_yr":-33.77,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star","bolometric_luminosity_solar":8.0572},"designations":[{"catalog":"HD","designation":"HD 21680"},{"catalog":"HIP","designation":"HIP 16202"}],"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."}