{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-28T00:06:45.857Z","years_from_j2000":26.654,"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":"ic-4901","name":"IC 4901","class":"intermediate_spiral_galaxy_sabc","category":"galaxy","object_type":"Intermediate spiral galaxy SABc","mag":11.65,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":96819421.24509653,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":298.59804166666663,"dec_deg":-58.71355555555556,"epoch_ra_deg":299.158873,"epoch_dec_deg":-58.643407,"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":"Pavo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-4901","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":11.97,"h_mag":9.2,"j_mag":9.69,"k_mag":8.85,"v_mag":11.65,"redshift":0.007184,"hubble_type":"SABc","wikidata_id":"Q3681190","redshift_cmb":0.0068950808783740936,"ngc_type_code":"G","uncertainties":{"distance_ly":[14582831.458964108,14582831.458964108]},"major_axis_arcmin":3.68,"minor_axis_arcmin":2.54,"position_angle_deg":130,"surface_brightness":23.22,"radial_velocity_km_s":2146},"designations":[{"catalog":"2MASX","designation":"2MASX J19542352-5842488"},{"catalog":"ESO","designation":"ESO 142-050"},{"catalog":"ESO","designation":"ESO 142-50"},{"catalog":"ESO-LV","designation":"ESO-LV 142-0500"},{"catalog":"IC","designation":"IC 4901"},{"catalog":"IRAS","designation":"IRAS 19501-5850"},{"catalog":"LEDA","designation":"LEDA 63797"},{"catalog":"PGC","designation":"PGC 63797"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","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."}