{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T02:53:17.698Z","years_from_j2000":26.677,"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":"k2-30-b","name":"K2-30 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1086.2377234753965,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":52.3420548,"dec_deg":22.2993491,"epoch_ra_deg":52.734402,"epoch_dec_deg":22.392112,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-30","semi_major_axis_km":7239040.963173,"periapsis_km":null,"mass_kg":1.0990196516702577e+27,"mass_msun":0.000552713,"constellation":"Taurus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/k2-30-b","radius_km":74280.3156931,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-30","host_v_mag":13.547,"eccentricity":0,"uncertainties":{"mass_kg":[5.124962106234362e+25,5.3147755175763755e+25],"radius_km":[3646.0982679000003,3574.606145],"distance_ly":[9.680321290632945,9.853184170822818],"host_mass_solar":[0.042,0.043],"inclination_deg":[0.24,0.26],"host_radius_solar":[0.032,0.032],"host_temperature_k":[40,40],"semi_major_axis_km":[113694.381732,113694.381732],"orbital_period_days":[0.000011,0.000011],"argument_of_periastron_deg":[51,100]},"host_mass_solar":0.9,"inclination_deg":86.92,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.844,"planets_in_system":1,"discovery_facility":"K2","host_spectral_type":"G6 V","host_temperature_k":5425,"orbital_period_days":4.098503,"transit_midpoint_bjd":2457063.80714,"equilibrium_temperature_k":1092,"argument_of_periastron_deg":120},"designations":[{"catalog":"Exoplanet","designation":"K2-30 b"},{"catalog":"Host star","designation":"K2-30"}],"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."}