{"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":"2026-09-04T17:59:47.048Z","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-278-c","name":"Kepler-278 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":1444.9706001984882,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":290.1072124,"dec_deg":38.7022694,"epoch_ra_deg":290.338179,"epoch_dec_deg":38.751805,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-278","semi_major_axis_km":42934588.89089999,"periapsis_km":null,"mass_kg":2.0842865858591913e+26,"mass_msun":0.000104822,"constellation":"Lyra","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-278-c","radius_km":20843.6308,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-278","host_v_mag":11.811,"eccentricity":0.616,"uncertainties":{"mass_kg":[1.2541552522361896e+26,5.912446189113466e+25],"radius_km":[427.33270000000005,427.33270000000005],"distance_ly":[20.441850973396892,20.441850973396892],"eccentricity":[0.023,0.015],"host_mass_solar":[0.061,0.061],"inclination_deg":[0.51,1.2],"host_radius_solar":[0.06,0.06],"host_temperature_k":[54,54],"semi_major_axis_km":[1047185.0948999999,1047185.0948999999],"orbital_period_days":[0.011,0.023],"argument_of_periastron_deg":[7.9,7.9]},"host_mass_solar":1.227,"inclination_deg":88.58,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":2.861,"planets_in_system":2,"discovery_facility":"Kepler","host_spectral_type":"K2 III-IV","host_temperature_k":4965,"orbital_period_days":51.111,"transit_midpoint_bjd":2455700.4118,"equilibrium_temperature_k":492,"argument_of_periastron_deg":20.8},"designations":[{"catalog":"Exoplanet","designation":"Kepler-278 c"},{"catalog":"Host star","designation":"Kepler-278"}],"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."}