{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T21:57:48.673Z","years_from_j2000":26.654,"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-142255","name":"HD 142255","class":"a4iv_v_white_subgiant","category":"star","object_type":"A4IV/V white subgiant","mag":6.92,"mag_band":"V","abs_mag":1.703,"abs_mag_band":"V","distance_ly":360.39366499842544,"distance_method":"parallax","ra_deg":238.83427500000002,"dec_deg":-43.391711,"epoch_ra_deg":239.298503,"epoch_dec_deg":-43.470457,"epoch_moved_arcsec":0.258,"pm_ra_mas_yr":5.31,"pm_dec_mas_yr":8.08,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Norma","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-142255","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":863276000,"mass_solar":1.95,"radius_solar":2.384,"spectral_type":"A4IV/V","color_index_bv":0.2,"luminosity_solar":18.14679779396928,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality D)","surface_gravity_log_g":3.905,"surface_temperature_k":7931,"proper_motion_ra_mas_yr":5.31,"proper_motion_dec_mas_yr":8.08,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate","bolometric_luminosity_solar":20.5196},"designations":[{"catalog":"HD","designation":"HD 142255"},{"catalog":"HIP","designation":"HIP 77964"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","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."}