{"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":"2026-09-02T04:15:36.227Z","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-91355","name":"HD 91355","class":"b8_a0_blue_white_star","category":"star","object_type":"B8/A0 blue-white star","mag":5.76,"mag_band":"V","abs_mag":-0.353,"abs_mag_band":"V","distance_ly":544.5014386228396,"distance_method":"parallax","ra_deg":157.98933,"dec_deg":-45.06671,"epoch_ra_deg":158.27508,"epoch_dec_deg":-45.204554,"epoch_moved_arcsec":0.412,"pm_ra_mas_yr":-15.4,"pm_dec_mas_yr":1.41,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Vela","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-91355","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"10320-4504","companions":[{"measured":2015,"magnitude":5.97,"components":null,"discoverer_code":"PZ    3","separation_arcsec":13.7,"position_angle_deg":218}],"spectral_type":"B8/A0","color_index_bv":-0.194,"luminosity_solar":120.55910077295344,"variable_mag_max":5.704,"variable_mag_min":5.964,"radial_velocity_km_s":-0.4,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality E)","proper_motion_ra_mas_yr":-15.4,"proper_motion_dec_mas_yr":1.41},"designations":[{"catalog":"HD","designation":"HD 91355"},{"catalog":"HIP","designation":"HIP 51561"},{"catalog":"HR","designation":"HR 4135"}],"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."}