{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.682","julian_year":2026.682,"time":"2026-09-06T23:39:05.361Z","years_from_j2000":26.682,"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-155358-b","name":"HD 155358 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":142.26843349091033,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":257.3930947,"dec_deg":33.3549277,"epoch_ra_deg":257.641589,"epoch_dec_deg":33.320357,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 155358","semi_major_axis_km":94246658.541,"periapsis_km":null,"mass_kg":1.8791527722859328e+27,"mass_msun":0.000945053,"constellation":"Hercules","discovered":"2007","featured":false,"url":"https://spacecatalog.org/object/hd-155358-b","radius_km":88017.78000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 155358","host_v_mag":7.28,"eccentricity":0.17,"uncertainties":{"mass_kg":[1.5185072907361073e+26,1.5185072907361073e+26],"distance_ly":[0.1539458102823029,0.1539458102823029],"eccentricity":[0.03,0.03],"host_mass_solar":[0.08,0.08],"host_radius_solar":[0.02,0.02],"host_temperature_k":[13,13],"semi_major_axis_km":[2991957.414,2991957.414],"orbital_period_days":[0.3,0.3],"argument_of_periastron_deg":[11,11]},"host_mass_solar":1.15,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.38,"planets_in_system":2,"discovery_facility":"McDonald Observatory","host_spectral_type":"G0","host_temperature_k":5905,"orbital_period_days":194.3,"periastron_epoch_bjd":2451224.8,"equilibrium_temperature_k":421.43,"argument_of_periastron_deg":143},"designations":[{"catalog":"Exoplanet","designation":"HD 155358 b"},{"catalog":"Host star","designation":"HD 155358"}],"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."}