{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.666","julian_year":2026.666,"time":"2026-09-01T03:10:32.069Z","years_from_j2000":26.666,"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-102855","name":"HD 102855","class":"f0_yellow_white_star","category":"star","object_type":"F0 yellow-white star","mag":8.02,"mag_band":"V","abs_mag":1.885,"abs_mag_band":"V","distance_ly":550.0108721552308,"distance_method":"parallax","ra_deg":177.732,"dec_deg":75.356027,"epoch_ra_deg":178.103783,"epoch_dec_deg":75.206546,"epoch_moved_arcsec":1.711,"pm_ra_mas_yr":-57.85,"pm_dec_mas_yr":-27.79,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Draco","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-102855","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":1548965800,"mass_solar":1.642,"radius_solar":2.273,"spectral_type":"F0","color_index_bv":0.371,"luminosity_solar":15.346169827992941,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1993yCat.3135....0C, quality E)","surface_gravity_log_g":3.862,"surface_temperature_k":6841,"proper_motion_ra_mas_yr":-57.85,"proper_motion_dec_mas_yr":-27.79,"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":10.3223},"designations":[{"catalog":"HD","designation":"HD 102855"},{"catalog":"HIP","designation":"HIP 57781"}],"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."}