{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T10:35:32.766Z","years_from_j2000":26.669,"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-2490","name":"IC 2490","class":"intermediate_spiral_galaxy_sabb","category":"galaxy","object_type":"Intermediate spiral galaxy SABb","mag":14.6,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":361059425.5769029,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":143.26520833333333,"dec_deg":29.928361111111112,"epoch_ra_deg":143.661387,"epoch_dec_deg":29.809636,"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":"Leo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-2490","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.6,"h_mag":11.08,"j_mag":11.79,"k_mag":10.9,"redshift":0.02445,"hubble_type":"SABb","wikidata_id":"Q3689222","redshift_cmb":0.025361677674584637,"ngc_type_code":"G","uncertainties":{"distance_ly":[20359983.65852821,20359983.65852821]},"major_axis_arcmin":0.97,"minor_axis_arcmin":0.65,"position_angle_deg":177,"surface_brightness":23.09,"radial_velocity_km_s":7240},"designations":[{"catalog":"2MASX","designation":"2MASX J09330359+2955417"},{"catalog":"IC","designation":"IC 2490"},{"catalog":"LEDA","designation":"LEDA 27121"},{"catalog":"MCG","designation":"MCG +05-23-010"},{"catalog":"PGC","designation":"PGC 27121"},{"catalog":"SDSS","designation":"SDSS J093303.64+295542.0"},{"catalog":"SDSS","designation":"SDSS J093303.64+295542.1"},{"catalog":"UGC","designation":"UGC 5087"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}