{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T12:00:31.737Z","years_from_j2000":26.683,"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-3738","name":"NGC 3738","class":"irregular_galaxy_i","category":"galaxy","object_type":"Irregular galaxy I","mag":11.45,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":173.95329166666667,"dec_deg":54.52388888888889,"epoch_ra_deg":174.322129,"epoch_dec_deg":54.375327,"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":"Ursa Major","discovered":"1789","featured":false,"url":"https://spacecatalog.org/object/ngc-3738","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":11.55,"v_mag":11.45,"redshift":0.00072,"hubble_type":"I","wikidata_id":"Q961484","redshift_cmb":0.0013057326950138837,"discovered_by":"William Herschel","ngc_type_code":"G","major_axis_arcmin":2.26,"minor_axis_arcmin":1.63,"wikipedia_article":"NGC 3738","position_angle_deg":156,"surface_brightness":21.77,"radial_velocity_km_s":217},"designations":[{"catalog":"IRAS","designation":"IRAS 11330+5448"},{"catalog":"IRAS","designation":"IRAS F11330+5448"},{"catalog":"LEDA","designation":"LEDA 35856"},{"catalog":"MCG","designation":"MCG +09-19-130"},{"catalog":"NGC","designation":"NGC 3738"},{"catalog":"PGC","designation":"PGC 35856"},{"catalog":"UGC","designation":"UGC 6565"}],"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."}