{"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":"2026-09-07T09:21:51.749Z","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":"hip-8541-b","name":"HIP 8541 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":505.9370346779896,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":27.5271962,"dec_deg":-54.4651633,"epoch_ra_deg":27.777334,"epoch_dec_deg":-54.331603,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HIP 8541","semi_major_axis_km":557850459.8403,"periapsis_km":null,"mass_kg":1.4642133162535285e+28,"mass_msun":0.00736374,"constellation":"Eridanus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/hip-8541-b","radius_km":80364.06,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HIP 8541","host_v_mag":7.88,"eccentricity":0.36,"uncertainties":{"mass_kg":[1.9550683376897005e+26,3.596946116509125e+27],"distance_ly":[2.067831434724153,2.080877689832823],"eccentricity":[0.047,0.06],"host_mass_solar":[0.115,0.115],"inclination_deg":[26.166,26.714],"host_radius_solar":[0.09,0.08],"host_temperature_k":[61,61],"semi_major_axis_km":[25132442.277599998,44879361.20999999],"orbital_period_days":[117.31046,215.24662],"argument_of_periastron_deg":[7.75,6.671]},"host_mass_solar":2.009,"inclination_deg":90.904,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":6.84,"planets_in_system":2,"discovery_facility":"Multiple Observatories","host_spectral_type":"K2 III/IV","host_temperature_k":4672,"orbital_period_days":1852.14387,"periastron_epoch_bjd":2454155.529,"equilibrium_temperature_k":305.12,"argument_of_periastron_deg":328.115},"designations":[{"catalog":"Exoplanet","designation":"HIP 8541 b"},{"catalog":"Host star","designation":"HIP 8541"}],"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."}