{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T12:29:03.561Z","years_from_j2000":26.675,"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":"k2-381-b","name":"K2-381 b","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":475.2131038970723,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":288.0267612,"dec_deg":-21.0075789,"epoch_ra_deg":288.425606,"epoch_dec_deg":-20.962991,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-381","semi_major_axis_km":null,"periapsis_km":null,"mass_kg":7.524931513417138e+24,"mass_msun":0.0000037844,"constellation":"Sagittarius","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/k2-381-b","radius_km":6856.4575,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-381","host_v_mag":12.883,"uncertainties":{"radius_km":[663.3224,905.6902],"distance_ly":[3.480088550237652,3.529012006895164],"host_mass_solar":[0.239,0.337],"inclination_deg":[5.43826,0.84968],"host_radius_solar":[0.047,0.052],"host_temperature_k":[138,138],"orbital_period_days":[0.000592,0.000596]},"host_mass_solar":0.754,"inclination_deg":88.8625,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.675,"planets_in_system":3,"discovery_facility":"K2","host_temperature_k":4473,"orbital_period_days":7.9389334,"transit_midpoint_bjd":2457304.844},"designations":[{"catalog":"Exoplanet","designation":"K2-381 b"}],"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."}