{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T21:07:22.684Z","years_from_j2000":26.654,"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":"hat-p-28","name":"HAT-P-28","class":"g3_yellow_star","category":"star","object_type":"G3 yellow star","mag":13.098,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":1308.9275134890577,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":13.0009159,"dec_deg":34.728402,"epoch_ra_deg":13.366987,"epoch_dec_deg":34.874436,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Andromeda","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hat-p-28","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"00520+3444","companions":[{"measured":2015,"magnitude":19,"components":null,"discoverer_code":"HTP  28","separation_arcsec":1,"position_angle_deg":211}],"mass_solar":1.025,"radius_solar":1.103,"spectral_type":"G3","stars_in_system":1,"planets_in_system":1,"surface_temperature_k":5680,"stellar_parameters_method":"NASA Exoplanet Archive composite parameters"},"designations":[],"source":{"id":"exoplanet_archive","name":"NASA Exoplanet Archive (Planetary Systems Composite Parameters)","url":"https://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=PSCompPars","license":"Public domain (NASA)"},"updated_at":"2026-08-27T19:16:43.430Z","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."}