{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-02T00:14:20.967Z","years_from_j2000":26.668,"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-23873","name":"HD 23873","class":"b9_5v_blue_white_main_sequence_star","category":"star","object_type":"B9.5V blue-white main-sequence star","mag":6.62,"mag_band":"V","abs_mag":1.184,"abs_mag_band":"V","distance_ly":398.7242148204525,"distance_method":"parallax","ra_deg":57.34062,"dec_deg":24.380956,"epoch_ra_deg":57.741469,"epoch_dec_deg":24.462794,"epoch_moved_arcsec":1.284,"pm_ra_mas_yr":18.34,"pm_dec_mas_yr":-44.53,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Taurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-23873","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"03494+2423","age_years":218513700,"companions":[{"measured":1987,"magnitude":7.4,"components":"Aa,Ab","discoverer_code":"OCC 253","separation_arcsec":1.6,"position_angle_deg":-1},{"measured":2022,"magnitude":7.53,"components":"AB","discoverer_code":"STTA 40","separation_arcsec":86.9,"position_angle_deg":309},{"measured":2018,"magnitude":13.83,"components":"AE","discoverer_code":"HL   31","separation_arcsec":115.5,"position_angle_deg":83},{"measured":2018,"magnitude":15.09,"components":"AG","discoverer_code":"HL   31","separation_arcsec":159.4,"position_angle_deg":212},{"measured":2018,"magnitude":14.57,"components":"AF","discoverer_code":"HL   31","separation_arcsec":181.8,"position_angle_deg":106}],"mass_solar":2.605,"radius_solar":2.204,"spectral_type":"B9.5V","color_index_bv":-0.027,"luminosity_solar":29.268468623787875,"radial_velocity_km_s":5.8,"spectral_type_source":"SIMBAD (2024A&A...690A.176N, quality C)","surface_gravity_log_g":4.027,"surface_temperature_k":10632,"proper_motion_ra_mas_yr":18.34,"proper_motion_dec_mas_yr":-44.53,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate","bolometric_luminosity_solar":55.7474},"designations":[{"catalog":"HD","designation":"HD 23873"},{"catalog":"HIP","designation":"HIP 17862"}],"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."}