{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T21:00:23.803Z","years_from_j2000":26.684,"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-156098-b","name":"HD 156098 b","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":157.36719068455153,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":259.264687,"dec_deg":-32.6630768,"epoch_ra_deg":259.703028,"epoch_dec_deg":-32.692645,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 156098","semi_major_axis_km":24982844.4069,"periapsis_km":null,"mass_kg":9.490622998783604e+25,"mass_msun":0.0000477297,"constellation":"Scorpius","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/hd-156098-b","radius_km":26277.772,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 156098","host_v_mag":5.53,"eccentricity":0.109,"uncertainties":{"mass_kg":[7.592498410971219e+24,2.087937061524043e+25],"distance_ly":[1.2162371325057362,1.2348280460355905],"eccentricity":[0.048,0.101],"host_mass_solar":[0.2,0.2],"host_radius_solar":[0.14133,0.119836],"host_temperature_k":[144.01,139.97],"semi_major_axis_km":[1346380.8362999998,1196782.9656],"orbital_period_days":[0.00601,0.01232],"argument_of_periastron_deg":[339.65,0]},"host_mass_solar":1.29,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":2.75716,"planets_in_system":2,"discovery_facility":"Multiple Observatories","host_temperature_k":6419.19,"orbital_period_days":21.85849,"periastron_epoch_bjd":2453478.163,"equilibrium_temperature_k":1257.73,"argument_of_periastron_deg":305.399},"designations":[{"catalog":"Exoplanet","designation":"HD 156098 b"}],"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."}