{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T19:22:30.284Z","years_from_j2000":26.681,"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-52100","name":"HD 52100","class":"a9iv_white_subgiant","category":"star","object_type":"A9IV white subgiant","mag":6.55,"mag_band":"V","abs_mag":0.794,"abs_mag_band":"V","distance_ly":461.9780042457046,"distance_method":"parallax","ra_deg":105.320895,"dec_deg":32.414562,"epoch_ra_deg":105.756828,"epoch_dec_deg":32.37657,"epoch_moved_arcsec":0.592,"pm_ra_mas_yr":-12.63,"pm_dec_mas_yr":-18.24,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Gemini","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-52100","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"07013+3225","companions":[{"measured":2016,"magnitude":13,"components":"AB","discoverer_code":"ES  339","separation_arcsec":16.9,"position_angle_deg":189},{"measured":2015,"magnitude":12.11,"components":"AC","discoverer_code":"ES  339","separation_arcsec":32,"position_angle_deg":296},{"measured":2015,"magnitude":12.71,"components":"AE","discoverer_code":"WAL  49","separation_arcsec":45.1,"position_angle_deg":118},{"measured":2015,"magnitude":11.84,"components":"AD","discoverer_code":"WAL  49","separation_arcsec":74.1,"position_angle_deg":274},{"measured":2016,"magnitude":8.26,"components":"AF","discoverer_code":"ARN  66","separation_arcsec":169.3,"position_angle_deg":301}],"spectral_type":"A9IV","uncertainties":{"metallicity_fe_h":[0.18,0.18]},"color_index_bv":0.27,"luminosity_solar":41.91794659325637,"metallicity_fe_h":0.04,"radial_velocity_km_s":-28,"spectral_type_source":"SIMBAD (2007A&A...463..671R, quality D)","surface_gravity_log_g":4.03,"surface_temperature_k":7253,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":-12.63,"proper_motion_dec_mas_yr":-18.24,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 52100"},{"catalog":"HIP","designation":"HIP 33823"},{"catalog":"HR","designation":"HR 2620"}],"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."}