{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T07:06:58.268Z","years_from_j2000":26.669,"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-37468","name":"48 σ Ori","class":"o9_5v_b0_2v_n_blue_main_sequence_star","category":"star","object_type":"O9.5V+B0.2V(n) blue main-sequence star","mag":3.77,"mag_band":"V","abs_mag":-3.816,"abs_mag_band":"V","distance_ly":1072.882924433407,"distance_method":"parallax","ra_deg":84.68653499999999,"dec_deg":-2.600069,"epoch_ra_deg":85.023843,"epoch_dec_deg":-2.58437,"epoch_moved_arcsec":0.123,"pm_ra_mas_yr":4.61,"pm_dec_mas_yr":-0.4,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Orion","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-37468","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"05387-0236","companions":[{"measured":2023,"magnitude":5.27,"components":"AB","discoverer_code":"BU 1032","separation_arcsec":0.3,"position_angle_deg":239},{"measured":2008,"magnitude":12,"components":"AB,G","discoverer_code":"TRN  19","separation_arcsec":3.2,"position_angle_deg":20},{"measured":2019,"magnitude":8.79,"components":"AB,C","discoverer_code":"STF 762","separation_arcsec":11.4,"position_angle_deg":239},{"measured":2021,"magnitude":6.56,"components":"AB,D","discoverer_code":"STF 762","separation_arcsec":13.5,"position_angle_deg":84},{"measured":2021,"magnitude":6.34,"components":"AB,E","discoverer_code":"STF 762","separation_arcsec":42,"position_angle_deg":62},{"measured":2016,"magnitude":7.86,"components":"AB,F","discoverer_code":"STF3135","separation_arcsec":208,"position_angle_deg":324},{"measured":2016,"magnitude":8.06,"components":"AB,H","discoverer_code":"SHJ  65","separation_arcsec":306.9,"position_angle_deg":125},{"measured":2016,"magnitude":8.44,"components":"AB,I","discoverer_code":"SHJ  65","separation_arcsec":524.7,"position_angle_deg":60}],"spectral_type":"O9.5V+B0.2V(n)","color_index_bv":-0.19,"luminosity_solar":2926.846862378789,"radial_velocity_km_s":29,"spectral_type_source":"SIMBAD (2021A&A...646A..11M, quality C)","surface_temperature_k":32135,"proper_motion_ra_mas_yr":4.61,"proper_motion_dec_mas_yr":-0.4,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"48 Sigma Ori"},{"catalog":"HD","designation":"HD 37468"},{"catalog":"HIP","designation":"HIP 26549"},{"catalog":"HR","designation":"HR 1931"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}