{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T14:19:25.944Z","years_from_j2000":26.678,"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-b","name":"HAT-P-28 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"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":13.367231,"epoch_dec_deg":34.874519,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HAT-P-28","semi_major_axis_km":6492547.58838,"periapsis_km":null,"mass_kg":1.1881807138006983e+27,"mass_msun":0.000597553,"constellation":"Andromeda","discovered":"2011","featured":false,"url":"https://spacecatalog.org/object/hat-p-28-b","radius_km":86646.4885,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HAT-P-28","host_v_mag":13.098,"eccentricity":0.051,"uncertainties":{"mass_kg":[7.022672195735883e+25,7.022672195735883e+25],"radius_km":[5861.473900000001,8081.0527],"distance_ly":[17.596136577818307,18.07558645306192],"eccentricity":[0.033,0.033],"host_mass_solar":[0.047,0.047],"inclination_deg":[0.9,0.9],"host_radius_solar":[0.069,0.091],"host_temperature_k":[90,90],"semi_major_axis_km":[104718.50949,104718.50949],"orbital_period_days":[0.000007,0.000007],"argument_of_periastron_deg":[90,90]},"host_mass_solar":1.025,"inclination_deg":88,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.103,"planets_in_system":1,"discovery_facility":"HATNet","host_spectral_type":"G3","host_temperature_k":5680,"orbital_period_days":3.257215,"transit_midpoint_bjd":2455417.59832,"equilibrium_temperature_k":1384,"argument_of_periastron_deg":233},"designations":[{"catalog":"Exoplanet","designation":"HAT-P-28 b"},{"catalog":"Host star","designation":"HAT-P-28"}],"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":"2026-09-02T19:50:56.720Z","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."}