{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.673","julian_year":2026.673,"time":"2026-09-03T23:05:04.768Z","years_from_j2000":26.673,"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":"k2-229-c","name":"K2-229 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":334.5190272414007,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":186.8729195,"dec_deg":-6.7218474,"epoch_ra_deg":187.218905,"epoch_dec_deg":-6.870499,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-229","semi_major_axis_km":11504076.25683,"periapsis_km":null,"mass_kg":4.180517507453966e+25,"mass_msun":0.0000210244,"constellation":"Virgo","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/k2-229-c","radius_km":12947.543,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-229","host_v_mag":10.985,"eccentricity":0,"uncertainties":{"mass_kg":[2.3888671471165517e+25,2.3888671471165517e+25],"radius_km":[382.68600000000004,765.3720000000001],"distance_ly":[3.4898732415691547,3.5648892084440056],"host_mass_solar":[0.01,0.01],"inclination_deg":[0.18,0.18],"host_radius_solar":[0.01,0.01],"host_temperature_k":[31,35],"semi_major_axis_km":[44879.361209999995,44879.361209999995],"orbital_period_days":[0.00043,0.00041]},"host_mass_solar":0.87,"inclination_deg":87.94,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.79,"planets_in_system":2,"discovery_facility":"K2","host_spectral_type":"G9","host_temperature_k":5315,"orbital_period_days":8.32727,"transit_midpoint_bjd":2457586.3431,"equilibrium_temperature_k":750},"designations":[{"catalog":"Exoplanet","designation":"K2-229 c"},{"catalog":"Host star","designation":"K2-229"}],"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."}