{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.664","julian_year":2026.664,"time":"2026-08-31T09:07:01.926Z","years_from_j2000":26.664,"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-4002","name":"IC 4002","class":"spiral_galaxy_sm","category":"galaxy","object_type":"Spiral galaxy Sm","mag":17.14,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":194.91920833333333,"dec_deg":36.76347222222222,"epoch_ra_deg":195.235879,"epoch_dec_deg":36.618558,"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":"Canes Venatici","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ic-4002","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":17.14,"hubble_type":"Sm","ngc_type_code":"G","major_axis_arcmin":0.43,"minor_axis_arcmin":0.23,"position_angle_deg":68,"surface_brightness":23.46},"designations":[{"catalog":"IC","designation":"IC 4002"},{"catalog":"PGC","designation":"PGC 44648"},{"catalog":"SDSS","designation":"SDSS J125940.61+364548.5"}],"source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}