{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T17:08:34.383Z","years_from_j2000":26.675,"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":"ngc-198","name":"NGC 198","class":"spiral_galaxy_sc","category":"galaxy","object_type":"Spiral galaxy Sc","mag":13.1,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":232075140.0257108,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":9.845749999999999,"dec_deg":2.7979166666666666,"epoch_ra_deg":10.191051,"epoch_dec_deg":2.945551,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Pisces","discovered":"1790","featured":false,"url":"https://spacecatalog.org/object/ngc-198","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.1,"h_mag":10.05,"j_mag":10.69,"k_mag":9.72,"redshift":0.017572,"hubble_type":"Sc","wikidata_id":"Q784893","redshift_cmb":0.016409866109732718,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[16961561.79362638,16961561.79362638]},"major_axis_arcmin":1.28,"minor_axis_arcmin":1.17,"wikipedia_article":"NGC 198","position_angle_deg":35,"surface_brightness":22.31,"radial_velocity_km_s":5222},"designations":[{"catalog":"2MASX","designation":"2MASX J00392298+0247525"},{"catalog":"IRAS","designation":"IRAS 00367+0231"},{"catalog":"IRAS","designation":"IRAS F00368+0231"},{"catalog":"LEDA","designation":"LEDA 2371"},{"catalog":"MCG","designation":"MCG +00-02-109"},{"catalog":"NGC","designation":"NGC 198"},{"catalog":"PGC","designation":"PGC 2371"},{"catalog":"UGC","designation":"UGC 414"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"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."}