{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T17:32:01.468Z","years_from_j2000":26.678,"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-3690a","name":"NGC 3690A","class":"spiral_galaxy_sm","category":"galaxy","object_type":"Spiral galaxy Sm","mag":12.86,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":172.12925,"dec_deg":58.561305555555556,"epoch_ra_deg":172.509712,"epoch_dec_deg":58.413413,"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":null,"featured":false,"url":"https://spacecatalog.org/object/ngc-3690a","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.32,"v_mag":12.86,"redshift":0.001,"hubble_type":"Sm","wikidata_id":"Q2430080","redshift_cmb":0.0015102557797632699,"discovered_by":"William Herschel","ngc_type_code":"G","major_axis_arcmin":0.21,"minor_axis_arcmin":0.15,"position_angle_deg":164,"surface_brightness":18.36,"radial_velocity_km_s":300},"designations":[{"catalog":"2MASX","designation":"2MASX J11283132+5833417"},{"catalog":"NGC","designation":"NGC 3690A"},{"catalog":"NGC","designation":"NGC 3690W"},{"catalog":"PGC","designation":"PGC 35326"},{"catalog":"SDSS","designation":"SDSS J112830.76+583342.8"},{"catalog":"UGC","designation":"UGC 6471"}],"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."}