{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T17:10:44.249Z","years_from_j2000":26.681,"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":"hd-20794-d","name":"HD 20794 d","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":19.57844981030513,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":49.9997666,"dec_deg":-43.0666533,"epoch_ra_deg":50.238264,"epoch_dec_deg":-42.968994,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 20794","semi_major_axis_km":54229228.12875,"periapsis_km":null,"mass_kg":2.866640576539862e+25,"mass_msun":0.0000144167,"constellation":"Eridanus","discovered":"2011","featured":false,"url":"https://spacecatalog.org/object/hd-20794-d","radius_km":13011.324,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 20794","host_v_mag":4.26,"eccentricity":0.077,"uncertainties":{"mass_kg":[3.5833007206748275e+24,3.5833007206748275e+24],"distance_ly":[0.027755907743694866,0.02785375465700989],"eccentricity":[0.055,0.084],"host_mass_solar":[0.01,0.01],"host_radius_solar":[0.03,0.03],"host_temperature_k":[64,64],"semi_major_axis_km":[239356.59312,224396.80604999998],"orbital_period_days":[0.1,0.1],"argument_of_periastron_deg":[22,25]},"host_mass_solar":0.79,"inclination_deg":90,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.93,"planets_in_system":4,"discovery_facility":"La Silla Observatory","host_spectral_type":"G6 V","host_temperature_k":5368,"orbital_period_days":89.68,"transit_midpoint_bjd":2460356.2,"equilibrium_temperature_k":388,"argument_of_periastron_deg":54},"designations":[{"catalog":"Exoplanet","designation":"HD 20794 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."}