{"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":"2026-09-05T15:36:08.723Z","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-4441","name":"NGC 4441","class":"lenticular_galaxy_s0_a","category":"galaxy","object_type":"Lenticular galaxy S0-a","mag":12.67,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":129983053.26227428,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":186.83479166666666,"dec_deg":64.80149999999999,"epoch_ra_deg":187.145217,"epoch_dec_deg":64.652795,"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":"Draco","discovered":"1790","featured":false,"url":"https://spacecatalog.org/object/ngc-4441","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":13.34,"h_mag":10.3,"j_mag":10.94,"k_mag":10.01,"v_mag":12.67,"redshift":0.008879,"hubble_type":"S0-a","wikidata_id":"Q1111490","redshift_cmb":0.009240495171390695,"discovered_by":"William Herschel","ngc_type_code":"G","uncertainties":{"distance_ly":[15018853.327736435,15018853.327736435]},"major_axis_arcmin":4.13,"minor_axis_arcmin":2.96,"wikipedia_article":"NGC 4441","position_angle_deg":171,"surface_brightness":25.13,"radial_velocity_km_s":2650},"designations":[{"catalog":"2MASX","designation":"2MASX J12272040+6448056"},{"catalog":"IRAS","designation":"IRAS 12250+6504"},{"catalog":"IRAS","designation":"IRAS F12250+6504"},{"catalog":"LEDA","designation":"LEDA 40836"},{"catalog":"MCG","designation":"MCG +11-15-056"},{"catalog":"NGC","designation":"NGC 4441"},{"catalog":"PGC","designation":"PGC 40836"},{"catalog":"SDSS","designation":"SDSS J122720.34+644805.4"},{"catalog":"SDSS","designation":"SDSS J122720.35+644805.3"},{"catalog":"SDSS","designation":"SDSS J122720.35+644805.4"},{"catalog":"SDSS","designation":"SDSS J122720.36+644805.3"},{"catalog":"UGC","designation":"UGC 7572"}],"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."}