{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T19:30:04.677Z","years_from_j2000":26.67,"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-81998","name":"HIP 81998","class":"k5v_orange_dwarf","category":"star","object_type":"K5V orange dwarf","mag":10.43,"mag_band":"V","abs_mag":7.506,"abs_mag_band":"V","distance_ly":125.39669022800092,"distance_method":"parallax","ra_deg":251.26245,"dec_deg":21.12156,"epoch_ra_deg":251.550892,"epoch_dec_deg":21.071796,"epoch_moved_arcsec":4.053,"pm_ra_mas_yr":-151.59,"pm_dec_mas_yr":10.81,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Hercules","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hip-81998","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":2699821500,"mass_solar":0.704,"radius_solar":0.654,"spectral_type":"K5V","color_index_bv":1.17,"luminosity_solar":0.08661637419723034,"variable_mag_max":10.382,"variable_mag_min":10.492,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1986AJ.....92..139S, quality C)","surface_gravity_log_g":4.668,"surface_temperature_k":4393,"proper_motion_ra_mas_yr":-151.59,"proper_motion_dec_mas_yr":10.81,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.1443},"designations":[{"catalog":"HIP","designation":"HIP 81998"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T18:38:07.546Z","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."}