{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.682","julian_year":2026.682,"time":"2026-09-06T22:58:58.638Z","years_from_j2000":26.682,"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-102574","name":"HD 102574","class":"g0v_yellow_main_sequence_star","category":"star","object_type":"G0V yellow main-sequence star","mag":6.24,"mag_band":"V","abs_mag":3.07,"abs_mag_band":"V","distance_ly":140.4031451667483,"distance_method":"parallax","ra_deg":177.09786,"dec_deg":-10.313105,"epoch_ra_deg":177.439565,"epoch_dec_deg":-10.463202,"epoch_moved_arcsec":4.056,"pm_ra_mas_yr":-105.9,"pm_dec_mas_yr":-109.06,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Crater","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-102574","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"11484-1019","age_years":4263281000,"companions":[{"measured":2016,"magnitude":14.49,"components":"AD","discoverer_code":"TOK 144","separation_arcsec":18.3,"position_angle_deg":164},{"measured":2015,"magnitude":9.17,"components":"AB","discoverer_code":"H 6 115","separation_arcsec":91.7,"position_angle_deg":65}],"mass_solar":1.281,"radius_solar":2.166,"spectral_type":"G0V","uncertainties":{"metallicity_fe_h":[0.012,0.012]},"color_index_bv":0.585,"luminosity_solar":5.152286445817564,"metallicity_fe_h":0.16,"radial_velocity_km_s":15,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality C)","surface_gravity_log_g":3.822,"surface_temperature_k":5916,"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":-105.9,"proper_motion_dec_mas_yr":-109.06,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":5.259},"designations":[{"catalog":"HD","designation":"HD 102574"},{"catalog":"HIP","designation":"HIP 57587"},{"catalog":"HR","designation":"HR 4529"}],"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."}