{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.667","julian_year":2026.667,"time":"2026-09-01T16:32:25.301Z","years_from_j2000":26.667,"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-218868","name":"HD 218868","class":"g8v_yellow_main_sequence_star","category":"star","object_type":"G8V yellow main-sequence star","mag":6.98,"mag_band":"V","abs_mag":5.052,"abs_mag_band":"V","distance_ly":79.26023981807897,"distance_method":"parallax","ra_deg":347.70874499999996,"dec_deg":45.512274,"epoch_ra_deg":348.017435,"epoch_dec_deg":45.655788,"epoch_moved_arcsec":7.981,"pm_ra_mas_yr":-86.84,"pm_dec_mas_yr":-286.41,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Andromeda","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-218868","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"23108+4531","age_years":13393420000,"companions":[{"measured":2014,"magnitude":12.43,"components":"AB","discoverer_code":"HJ 1853","separation_arcsec":42.5,"position_angle_deg":328},{"measured":2016,"magnitude":15.3,"components":"AC","discoverer_code":"HJ 1853","separation_arcsec":50.4,"position_angle_deg":87}],"mass_solar":0.869,"radius_solar":0.997,"spectral_type":"G8V","uncertainties":{"metallicity_fe_h":[0.027,0.027]},"color_index_bv":0.75,"luminosity_solar":0.8302330159249539,"metallicity_fe_h":0.22,"radial_velocity_km_s":-31.5,"spectral_type_source":"SIMBAD (2003AJ....126.2048G, quality C)","surface_gravity_log_g":4.384,"surface_temperature_k":5435,"metallicity_fe_h_source":"Median of 8 spectroscopic determinations in 9 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-86.84,"proper_motion_dec_mas_yr":-286.41,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.7824},"designations":[{"catalog":"HD","designation":"HD 218868"},{"catalog":"HIP","designation":"HIP 114456"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}