{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T14:57:43.162Z","years_from_j2000":26.683,"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-3154-b","name":"LHS 3154 b","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":51.404202066425064,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":241.6367309,"dec_deg":40.9068221,"epoch_ra_deg":241.867913,"epoch_dec_deg":40.833999,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"LHS 3154","semi_major_axis_km":3383903.835234,"periapsis_km":null,"mass_kg":7.853400746145663e+25,"mass_msun":0.0000394959,"constellation":"Hercules","discovered":"2023","featured":false,"url":"https://spacecatalog.org/object/lhs-3154-b","radius_km":23535.189000000002,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"LHS 3154","host_v_mag":17.65,"eccentricity":0.076,"uncertainties":{"mass_kg":[4.897177651588931e+24,5.016621008944759e+24],"distance_ly":[0.05870814798901381,0.05870814798901381],"eccentricity":[0.047,0.057],"host_mass_solar":[0.0027,0.0027],"host_radius_solar":[0.0038,0.0038],"host_temperature_k":[77,77],"semi_major_axis_km":[26927.616726,26927.616726],"orbital_period_days":[0.00081,0.0008],"argument_of_periastron_deg":[47,102]},"host_mass_solar":0.1118,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.1405,"planets_in_system":1,"discovery_facility":"McDonald Observatory","host_spectral_type":"M6.5","host_temperature_k":2861,"orbital_period_days":3.71778,"periastron_epoch_bjd":2458874.02,"transit_midpoint_bjd":2458874,"equilibrium_temperature_k":343.83,"argument_of_periastron_deg":82},"designations":[{"catalog":"Exoplanet","designation":"LHS 3154 b"},{"catalog":"Host star","designation":"LHS 3154"}],"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."}