{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.676","julian_year":2026.676,"time":"2026-09-04T20:39:54.013Z","years_from_j2000":26.676,"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-55856","name":"HD 55856","class":"b2iv_blue_white_subgiant","category":"star","object_type":"B2IV blue-white subgiant","mag":6.34,"mag_band":"V","abs_mag":-1.861,"abs_mag_band":"V","distance_ly":1424.2635840900077,"distance_method":"parallax","ra_deg":108.451605,"dec_deg":-22.905778,"epoch_ra_deg":108.735439,"epoch_dec_deg":-22.95126,"epoch_moved_arcsec":0.128,"pm_ra_mas_yr":-3.57,"pm_dec_mas_yr":3.19,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Canis Major","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-55856","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"07138-2254","companions":[{"measured":2016,"magnitude":9.1,"components":null,"discoverer_code":"HJ 3938","separation_arcsec":19.3,"position_angle_deg":251}],"radius_solar":8.555,"spectral_type":"B2IV","color_index_bv":-0.184,"luminosity_solar":483.50392059162147,"radial_velocity_km_s":17,"spectral_type_source":"SIMBAD (1988MSS...C04....0H, quality C)","surface_gravity_log_g":3.52,"surface_temperature_k":19301,"proper_motion_ra_mas_yr":-3.57,"proper_motion_dec_mas_yr":3.19,"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"},"designations":[{"catalog":"HD","designation":"HD 55856"},{"catalog":"HIP","designation":"HIP 34940"},{"catalog":"HR","designation":"HR 2733"}],"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."}