{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-09-01T00:55:44.077Z","years_from_j2000":26.665,"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-156331","name":"HD 156331","class":"f3iv_v_yellow_white_subgiant","category":"star","object_type":"F3IV/V yellow-white subgiant","mag":6.27,"mag_band":"V","abs_mag":2.415,"abs_mag_band":"V","distance_ly":192.53630673737027,"distance_method":"parallax","ra_deg":259.877145,"dec_deg":-50.063762,"epoch_ra_deg":260.396698,"epoch_dec_deg":-50.091888,"epoch_moved_arcsec":0.883,"pm_ra_mas_yr":7.16,"pm_dec_mas_yr":-32.33,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Ara","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-156331","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"17195-5004","companions":[{"measured":2025,"magnitude":7,"components":null,"discoverer_code":"FIN 356","separation_arcsec":0.1,"position_angle_deg":249}],"spectral_type":"F3IV/V","color_index_bv":0.413,"luminosity_solar":9.41889596522841,"radial_velocity_km_s":11,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality D)","surface_temperature_k":6713,"proper_motion_ra_mas_yr":7.16,"proper_motion_dec_mas_yr":-32.33,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 156331"},{"catalog":"HIP","designation":"HIP 84759"},{"catalog":"HR","designation":"HR 6423"}],"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."}