{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T17:21:05.685Z","years_from_j2000":26.681,"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-120-b","name":"Kepler-120 b","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":1267.5415307205799,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":287.8915707,"dec_deg":39.3390979,"epoch_ra_deg":288.118532,"epoch_dec_deg":39.383146,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-120","semi_major_axis_km":8227882.888499999,"periapsis_km":null,"mass_kg":5.076342687622672e+25,"mass_msun":0.0000255297,"constellation":"Lyra","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-120-b","radius_km":13712.915,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-120","host_v_mag":14.995,"eccentricity":0,"uncertainties":{"mass_kg":[4.479125900843535e+25,5.793002831757638e+25],"radius_km":[1084.277,1084.277],"distance_ly":[10.394603757832613,10.567466638022488],"host_mass_solar":[0.014,0.014],"host_radius_solar":[0.028,0.028],"host_temperature_k":[150,150],"orbital_period_days":[0.000008,0.000008]},"host_mass_solar":0.654,"inclination_deg":89.91,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.534,"planets_in_system":2,"discovery_facility":"Kepler","host_spectral_type":"M0 V","host_temperature_k":4096,"orbital_period_days":6.312501,"transit_midpoint_bjd":2454965.65419,"equilibrium_temperature_k":575},"designations":[{"catalog":"Exoplanet","designation":"Kepler-120 b"},{"catalog":"Host star","designation":"Kepler-120"}],"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."}