{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.673","julian_year":2026.673,"time":"2026-09-03T17:29:41.099Z","years_from_j2000":26.673,"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-3846","name":"NGC 3846","class":"barred_spiral_galaxy_sbbc","category":"galaxy","object_type":"Barred spiral galaxy SBbc","mag":13.63,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":473149761.23179626,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":176.12116666666665,"dec_deg":55.652249999999995,"epoch_ra_deg":176.482638,"epoch_dec_deg":55.503215,"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":"1831","featured":false,"url":"https://spacecatalog.org/object/ngc-3846","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.63,"h_mag":11.3,"j_mag":11.86,"k_mag":10.92,"redshift":0.03247,"hubble_type":"SBbc","wikidata_id":"Q1106822","redshift_cmb":0.03304894205696618,"discovered_by":"John Frederick William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[23844883.41032117,23844883.41032117]},"major_axis_arcmin":0.97,"minor_axis_arcmin":0.63,"position_angle_deg":134,"surface_brightness":21.95,"radial_velocity_km_s":9576},"designations":[{"catalog":"2MASX","designation":"2MASX J11442911+5539073"},{"catalog":"IRAS","designation":"IRAS 11417+5556"},{"catalog":"IRAS","designation":"IRAS F11417+5555"},{"catalog":"LEDA","designation":"LEDA 36539"},{"catalog":"MCG","designation":"MCG +09-19-171"},{"catalog":"NGC","designation":"NGC 3846"},{"catalog":"PGC","designation":"PGC 36539"},{"catalog":"SDSS","designation":"SDSS J114429.05+553908.3"},{"catalog":"SDSS","designation":"SDSS J114429.06+553908.0"},{"catalog":"SDSS","designation":"SDSS J114429.07+553908.1"},{"catalog":"SDSS","designation":"SDSS J114429.07+553908.2"},{"catalog":"SDSS","designation":"SDSS J114429.08+553908.2"},{"catalog":"UGC","designation":"UGC 6710"}],"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."}