{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-08T00:04:15.486Z","years_from_j2000":26.684,"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":"hip-41378-g","name":"HIP 41378 g","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":346.6683523113494,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":126.6158279,"dec_deg":10.0803708,"epoch_ra_deg":126.981548,"epoch_dec_deg":9.992614,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HIP 41378","semi_major_axis_km":null,"periapsis_km":null,"mass_kg":4.067046317965929e+25,"mass_msun":0.0000204538,"constellation":"Cancer","discovered":"2025","featured":false,"url":"https://spacecatalog.org/object/hip-41378-g","radius_km":15945.25,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HIP 41378","host_v_mag":8.93,"eccentricity":0.055,"uncertainties":{"mass_kg":[5.852724510435552e+24,6.808271369282171e+24],"distance_ly":[2.178724603147846,2.2048171133651855],"eccentricity":[0.054,0.024],"host_mass_solar":[0.02,0.03],"inclination_deg":[10,1],"host_radius_solar":[0.009,0.009],"host_temperature_k":[77,77],"orbital_period_days":[0.12,0.12],"argument_of_periastron_deg":[115,5]},"host_mass_solar":1.22,"inclination_deg":95,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.3,"planets_in_system":6,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"F6","host_temperature_k":6290,"orbital_period_days":63.19,"transit_midpoint_bjd":2458777.86,"equilibrium_temperature_k":605,"argument_of_periastron_deg":205},"designations":[{"catalog":"Exoplanet","designation":"HIP 41378 g"}],"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."}