{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.674","julian_year":2026.674,"time":"2026-09-04T03:36:45.577Z","years_from_j2000":26.674,"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-16538","name":"ι² For","class":"f6vfe_0_7ch_0_4_yellow_white_main_sequence_star","category":"star","object_type":"F6VFe-0.7CH-0.4 yellow-white main-sequence star","mag":5.84,"mag_band":"V","abs_mag":3.186,"abs_mag_band":"V","distance_ly":110.71149932130453,"distance_method":"parallax","ra_deg":39.577725,"dec_deg":-30.194062,"epoch_ra_deg":39.868208,"epoch_dec_deg":-30.078157,"epoch_moved_arcsec":3.289,"pm_ra_mas_yr":98.67,"pm_dec_mas_yr":-73.97,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Fornax","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-16538","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"02383-3012","age_years":2974392200,"companions":[{"measured":2016,"magnitude":13.74,"components":null,"discoverer_code":"UC  766","separation_arcsec":81.8,"position_angle_deg":6}],"mass_solar":1.368,"radius_solar":1.893,"spectral_type":"F6VFe-0.7CH-0.4","color_index_bv":0.476,"luminosity_solar":4.630202658603084,"radial_velocity_km_s":29,"spectral_type_source":"SIMBAD (2006AJ....132..161G, quality C)","surface_gravity_log_g":3.997,"surface_temperature_k":6237,"proper_motion_ra_mas_yr":98.67,"proper_motion_dec_mas_yr":-73.97,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":4.8961},"designations":[{"catalog":"Bayer/Flamsteed","designation":"Iota2 For"},{"catalog":"HD","designation":"HD 16538"},{"catalog":"HIP","designation":"HIP 12288"},{"catalog":"HR","designation":"HR 777"}],"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."}