{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T06:17:39.183Z","years_from_j2000":26.671,"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-1798","name":"HD 1798","class":"f2iv_v_yellow_white_subgiant","category":"star","object_type":"F2IV/V yellow-white subgiant","mag":9.25,"mag_band":"V","abs_mag":4.506,"abs_mag_band":"V","distance_ly":289.9168164322584,"distance_method":"parallax","ra_deg":5.551665000000001,"dec_deg":-43.880986,"epoch_ra_deg":5.88349,"epoch_dec_deg":-43.731968,"epoch_moved_arcsec":0.362,"pm_ra_mas_yr":-12.01,"pm_dec_mas_yr":6.35,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Phoenix","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-1798","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"00222-4353","companions":[{"measured":2015,"magnitude":11.02,"components":null,"discoverer_code":"HDS  50","separation_arcsec":14.5,"position_angle_deg":357}],"spectral_type":"F2IV/V","color_index_bv":0.385,"luminosity_solar":1.3727770182085481,"variable_mag_max":9.186,"variable_mag_min":9.336,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality D)","proper_motion_ra_mas_yr":-12.01,"proper_motion_dec_mas_yr":6.35},"designations":[{"catalog":"HD","designation":"HD 1798"},{"catalog":"HIP","designation":"HIP 1753"}],"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."}