{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.666","julian_year":2026.666,"time":"2026-09-01T04:17:45.643Z","years_from_j2000":26.666,"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":"toi-561-e","name":"TOI-561 e","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":279.8389105171887,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":148.1851516,"dec_deg":6.216103,"epoch_ra_deg":148.537794,"epoch_dec_deg":6.090074,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"TOI-561","semi_major_axis_km":49367297.331,"periapsis_km":null,"mass_kg":7.40548815606131e+25,"mass_msun":0.0000372433,"constellation":"Sextans","discovered":"2020","featured":false,"url":"https://spacecatalog.org/object/toi-561-e","radius_km":16053.6777,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"TOI-561","host_v_mag":10.252,"eccentricity":0.074,"uncertainties":{"mass_kg":[8.361035014907931e+24,8.361035014907931e+24],"radius_km":[287.0145,287.0145],"distance_ly":[1.6086032548989786,1.6268680120511163],"eccentricity":[0.039,0.044],"host_mass_solar":[0.036,0.036],"inclination_deg":[0.094,0.095],"host_radius_solar":[0.005,0.005],"host_temperature_k":[54,57],"semi_major_axis_km":[747989.3535,747989.3535],"orbital_period_days":[0.00027,0.00027],"argument_of_periastron_deg":[39,26]},"host_mass_solar":0.806,"inclination_deg":89.864,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.843,"planets_in_system":4,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_spectral_type":"G9 V","host_temperature_k":5342,"orbital_period_days":77.144,"transit_midpoint_bjd":2458538.1803,"equilibrium_temperature_k":416,"argument_of_periastron_deg":148},"designations":[{"catalog":"Exoplanet","designation":"TOI-561 e"}],"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":"2026-08-30T09:56:50.739Z","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."}