{"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":"2026-09-02T13:41:59.336Z","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":"kepler-154-c","name":"Kepler-154 c","class":"neptune_like_planet","category":"exoplanet","object_type":"Neptune-like planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2985.0223076289617,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":289.7805393,"dec_deg":49.8965624,"epoch_ra_deg":289.956558,"epoch_dec_deg":49.945196,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-154","semi_major_axis_km":45328154.8221,"periapsis_km":null,"mass_kg":5.380923248880032e+25,"mass_msun":0.0000270614,"constellation":"Cygnus","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-154-c","radius_km":18815.395,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-154","host_v_mag":14.646,"eccentricity":0,"uncertainties":{"radius_km":[3954.422,3954.422],"distance_ly":[53.2515517898127,55.18565910967299],"host_mass_solar":[0.03,0.032],"host_radius_solar":[0.19,0.19],"host_temperature_k":[108,108],"orbital_period_days":[0.000406,0.000406]},"host_mass_solar":0.933,"inclination_deg":89.13,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.001,"planets_in_system":5,"discovery_facility":"Kepler","host_temperature_k":5690,"orbital_period_days":62.303276,"transit_midpoint_bjd":2455012.09423,"equilibrium_temperature_k":454},"designations":[{"catalog":"Exoplanet","designation":"Kepler-154 c"}],"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":"2026-09-01T22:58:55.274Z","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."}