{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T04:17:48.599Z","years_from_j2000":26.669,"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":"gj-357-b","name":"GJ 357 b","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":30.795065486897254,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":144.0074644,"dec_deg":-21.6650634,"epoch_ra_deg":144.315849,"epoch_dec_deg":-21.784882,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"GJ 357","semi_major_axis_km":5385523.345199999,"periapsis_km":null,"mass_kg":1.0929067198058225e+25,"mass_msun":0.00000549639,"constellation":"Hydra","discovered":"2019","featured":false,"url":"https://spacecatalog.org/object/gj-357-b","radius_km":7653.72,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"GJ 357","host_v_mag":10.91,"uncertainties":{"mass_kg":[1.7916503603374138e+24,1.7916503603374138e+24],"radius_km":[382.68600000000004,382.68600000000004],"distance_ly":[0.01666659090132559,0.01666659090132559],"host_mass_solar":[0.011,0.011],"inclination_deg":[0.483,0.483],"host_radius_solar":[0.015,0.015],"host_temperature_k":[51,51],"semi_major_axis_km":[59839.14828,59839.14828],"orbital_period_days":[0.000002,0.000002]},"host_mass_solar":0.342,"inclination_deg":89.228,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.337,"planets_in_system":3,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_spectral_type":"M2.5 V","host_temperature_k":3505,"orbital_period_days":3.9306,"transit_midpoint_bjd":2459272.6757,"equilibrium_temperature_k":518},"designations":[{"catalog":"Exoplanet","designation":"GJ 357 b"},{"catalog":"Host star","designation":"GJ 357"}],"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":"2026-09-01T22:58:55.274Z","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."}