{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.676","julian_year":2026.676,"time":"2026-09-05T00:47:29.555Z","years_from_j2000":26.676,"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":"kepler-1638-b","name":"Kepler-1638 b","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":4975.580773344464,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":295.4823299,"dec_deg":48.5244695,"epoch_ra_deg":295.672595,"epoch_dec_deg":48.586959,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-1638","semi_major_axis_km":111450413.6715,"periapsis_km":null,"mass_kg":2.4844218330012138e+25,"mass_msun":0.0000124945,"constellation":"Cygnus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/kepler-1638-b","radius_km":11927.047,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-1638","host_v_mag":14.769,"eccentricity":0,"uncertainties":{"radius_km":[1403.182,2104.773],"distance_ly":[155.83751727306,166.04621189559407],"host_mass_solar":[0.059,0.049],"inclination_deg":[0.0844,0.0021],"host_radius_solar":[0.079,0.166],"host_temperature_k":[111.43,96.7],"semi_major_axis_km":[2991957.414,3141555.2846999997],"orbital_period_days":[0.01303,0.01303]},"host_mass_solar":0.97,"inclination_deg":89.9954,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.95,"planets_in_system":1,"discovery_facility":"Kepler","host_temperature_k":5710,"orbital_period_days":259.33683,"transit_midpoint_bjd":2454998.6905,"equilibrium_temperature_k":304},"designations":[{"catalog":"Exoplanet","designation":"Kepler-1638 b"},{"catalog":"Host star","designation":"Kepler-1638"}],"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."}