{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T10:42:15.892Z","years_from_j2000":26.686,"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":"xo-2-n-b","name":"XO-2 N b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":503.1712285949516,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":117.0267691,"dec_deg":50.2251472,"epoch_ra_deg":117.531869,"epoch_dec_deg":50.158639,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"XO-2 N","semi_major_axis_km":5484257.939861999,"periapsis_km":null,"mass_kg":1.1939263573412642e+27,"mass_msun":0.000600443,"constellation":"Lynx","discovered":"2007","featured":false,"url":"https://spacecatalog.org/object/xo-2-n-b","radius_km":70991.67803970001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"XO-2 N","host_v_mag":11.246,"eccentricity":0,"uncertainties":{"mass_kg":[3.226827992814228e+25,3.226827992814228e+25],"radius_km":[857.9054748,857.9054748],"distance_ly":[4.673820892680934,4.758621550887287],"host_mass_solar":[0.05,0.05],"inclination_deg":[0.28,0.33],"host_radius_solar":[0.033,0.033],"host_temperature_k":[18,18],"semi_major_axis_km":[97238.61595499999,97238.61595499999],"orbital_period_days":[2.52e-7,2.52e-7]},"host_mass_solar":0.96,"inclination_deg":88.01,"stars_in_system":2,"discovery_method":"Transit","host_radius_solar":0.998,"planets_in_system":4,"discovery_facility":"XO","host_spectral_type":"G8 V","host_temperature_k":5290,"orbital_period_days":2.61585906,"periastron_epoch_bjd":2458843.2176,"transit_midpoint_bjd":2455565.54648,"equilibrium_temperature_k":1328,"argument_of_periastron_deg":90},"designations":[{"catalog":"Exoplanet","designation":"XO-2 N b"},{"catalog":"Host star","designation":"XO-2 N"}],"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."}