{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.663","julian_year":2026.663,"time":"2026-08-31T03:53:15.025Z","years_from_j2000":26.663,"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-106946","name":"HD 106946","class":"f2vs_yellow_white_main_sequence_star","category":"star","object_type":"F2Vs yellow-white main-sequence star","mag":7.85,"mag_band":"V","abs_mag":3.009,"abs_mag_band":"V","distance_ly":303.11930044585444,"distance_method":"parallax","ra_deg":184.46211,"dec_deg":25.571344,"epoch_ra_deg":184.801339,"epoch_dec_deg":25.422121,"epoch_moved_arcsec":0.377,"pm_ra_mas_yr":-10.5,"pm_dec_mas_yr":-9.49,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Coma Berenices","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-106946","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":1699510900,"mass_solar":1.388,"radius_solar":1.563,"spectral_type":"F2Vs","uncertainties":{"metallicity_fe_h":[0.105,0.105]},"color_index_bv":0.365,"luminosity_solar":5.4500438934176145,"metallicity_fe_h":0.074,"radial_velocity_km_s":4.2,"spectral_type_source":"SIMBAD (2001AJ....121.2148G, quality C)","surface_gravity_log_g":4.12,"surface_temperature_k":6747,"metallicity_fe_h_source":"Median of 2 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":-10.5,"proper_motion_dec_mas_yr":-9.49,"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":4.6133},"designations":[{"catalog":"HD","designation":"HD 106946"},{"catalog":"HIP","designation":"HIP 59957"}],"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."}