{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T06:20:29.478Z","years_from_j2000":26.677,"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-9618-b","name":"HIP 9618 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":220.3114577073504,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":30.9050061,"dec_deg":21.2813274,"epoch_ra_deg":31.278557,"epoch_dec_deg":21.410557,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HIP 9618","semi_major_axis_km":21691691.251499996,"periapsis_km":null,"mass_kg":4.956899330266845e+25,"mass_msun":0.000024929,"constellation":"Aries","discovered":"2023","featured":false,"url":"https://spacecatalog.org/object/hip-9618-b","radius_km":24417.798578187,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HIP 9618","host_v_mag":9.2,"eccentricity":0,"uncertainties":{"mass_kg":[1.0152685375245345e+25,1.0152685375245345e+25],"radius_km":[562.330161418,665.888182068],"distance_ly":[0.5084777928604031,0.5107608875044202],"host_mass_solar":[0.0325,0.0335],"host_radius_solar":[0.0163,0.0173],"host_temperature_k":[71,75],"semi_major_axis_km":[448793.61209999997,448793.61209999997],"orbital_period_days":[0.000047,0.000047]},"host_mass_solar":0.942,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.9593,"planets_in_system":2,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_temperature_k":5649,"orbital_period_days":20.772858,"transit_midpoint_bjd":2458767.4228,"equilibrium_temperature_k":640.88,"argument_of_periastron_deg":90},"designations":[{"catalog":"Exoplanet","designation":"HIP 9618 b"},{"catalog":"Host star","designation":"HIP 9618"}],"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."}