{"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":"2026-08-31T23:07:53.774Z","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":"hip-18","name":"HIP 18","class":"k5v_orange_dwarf","category":"star","object_type":"K5V orange dwarf","mag":11.03,"mag_band":"V","abs_mag":7.773,"abs_mag_band":"V","distance_ly":146.1927470275982,"distance_method":"parallax","ra_deg":0.05283,"dec_deg":-4.05368,"epoch_ra_deg":0.39598,"epoch_dec_deg":-3.904039,"epoch_moved_arcsec":3.451,"pm_ra_mas_yr":-127.22,"pm_dec_mas_yr":23.78,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Pisces","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hip-18","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"radius_solar":0.713,"spectral_type":"K5V","color_index_bv":1.567,"luminosity_solar":0.06773295140086069,"variable_mag_max":10.948,"variable_mag_min":11.088,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1986AJ.....92..139S, quality C)","surface_gravity_log_g":4.56,"surface_temperature_k":4169,"proper_motion_ra_mas_yr":-127.22,"proper_motion_dec_mas_yr":23.78,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.1391},"designations":[{"catalog":"HIP","designation":"HIP 18"}],"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."}