{"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":"2026-09-07T14:11:59.588Z","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":"hd-103891-b","name":"HD 103891 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":181.08626094124625,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":179.4382907,"dec_deg":-8.5486195,"epoch_ra_deg":179.782046,"epoch_dec_deg":-8.698182,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 103891","semi_major_axis_km":489185037.18899995,"periapsis_km":null,"mass_kg":5.485580093296923e+27,"mass_msun":0.00275878,"constellation":"Virgo","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/hd-103891-b","radius_km":84190.92,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 103891","host_v_mag":6.59451,"eccentricity":0.31,"uncertainties":{"mass_kg":[1.5944246637956455e+27,1.7842371237713173e+27],"distance_ly":[1.4279126216439026,1.4500912553286411],"eccentricity":[0.03,0.03],"host_mass_solar":[0.01,0.01],"inclination_deg":[7.1,13],"host_radius_solar":[0.05,0.05],"host_temperature_k":[20,20],"semi_major_axis_km":[1495978.707,2991957.414],"orbital_period_days":[15,14],"argument_of_periastron_deg":[8.17,8.05]},"host_mass_solar":1.28,"inclination_deg":27.4,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":2.22,"planets_in_system":1,"discovery_facility":"La Silla Observatory","host_spectral_type":"F9","host_temperature_k":6072,"orbital_period_days":1919,"periastron_epoch_bjd":2455245,"equilibrium_temperature_k":241.25,"argument_of_periastron_deg":181.49},"designations":[{"catalog":"Exoplanet","designation":"HD 103891 b"},{"catalog":"Host star","designation":"HD 103891"}],"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."}