{"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":"2026-09-07T18:03:50.740Z","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":"lhs-1678-d","name":"LHS 1678 d","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":64.8340170752897,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":68.1789866,"dec_deg":-39.7908744,"epoch_ra_deg":68.408326,"epoch_dec_deg":-39.73341,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"LHS 1678","semi_major_axis_km":5983914.828,"periapsis_km":null,"mass_kg":5.416756256086781e+24,"mass_msun":0.00000272416,"constellation":"Caelum","discovered":"2024","featured":false,"url":"https://spacecatalog.org/object/lhs-1678-d","radius_km":6256.9161,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"LHS 1678","host_v_mag":12.6,"eccentricity":0.036,"uncertainties":{"radius_km":[459.2232,446.46700000000004],"distance_ly":[0.030658699505373883,0.030658699505373883],"eccentricity":[0.027,0.06],"host_mass_solar":[0.014,0.014],"inclination_deg":[0.13,0.14],"host_radius_solar":[0.01,0.01],"host_temperature_k":[50,50],"semi_major_axis_km":[254316.38018999997,269276.16725999996],"orbital_period_days":[0.0000075,0.0000096],"argument_of_periastron_deg":[132,109]},"host_mass_solar":0.345,"inclination_deg":88.31,"stars_in_system":2,"discovery_method":"Transit","host_radius_solar":0.329,"planets_in_system":3,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_spectral_type":"M2.0 V","host_temperature_k":3490,"orbital_period_days":4.9652229,"transit_midpoint_bjd":2459000.45806,"equilibrium_temperature_k":462.95,"argument_of_periastron_deg":23},"designations":[{"catalog":"Exoplanet","designation":"LHS 1678 d"}],"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."}