{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T09:43:48.486Z","years_from_j2000":26.672,"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-181-c","name":"Kepler-181 c","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1987.215362843906,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":296.1512831,"dec_deg":50.0957806,"epoch_ra_deg":296.333596,"epoch_dec_deg":50.15982,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-181","semi_major_axis_km":7330295.664299999,"periapsis_km":null,"mass_kg":2.7591415549196174e+25,"mass_msun":0.0000138761,"constellation":"Cygnus","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-181-c","radius_km":12692.419,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-181","host_v_mag":14.854,"eccentricity":0,"uncertainties":{"radius_km":[6250.5380000000005,6250.5380000000005],"distance_ly":[25.916385773372433,25.916385773372433],"host_mass_solar":[0.03,0.026],"host_radius_solar":[0.367,0.367],"host_temperature_k":[200,200],"orbital_period_days":[0.000008,0.000008]},"host_mass_solar":0.81,"inclination_deg":87.09,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.749,"planets_in_system":2,"discovery_facility":"Kepler","host_temperature_k":5333,"orbital_period_days":4.302149,"transit_midpoint_bjd":2455006.43717,"equilibrium_temperature_k":937},"designations":[{"catalog":"Exoplanet","designation":"Kepler-181 c"},{"catalog":"Host star","designation":"Kepler-181"}],"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."}