{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T07:39:43.316Z","years_from_j2000":26.683,"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-2988","name":"NGC 2988","class":"spiral_galaxy_sbc","category":"galaxy","object_type":"Spiral galaxy Sbc","mag":15.28,"mag_band":"B","abs_mag":null,"abs_mag_band":null,"distance_ly":378420649.8797753,"distance_method":"redshift (CMB frame), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":146.69987500000002,"dec_deg":22.012138888888888,"epoch_ra_deg":147.077828,"epoch_dec_deg":21.888108,"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":"1855","featured":false,"url":"https://spacecatalog.org/object/ngc-2988","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.28,"redshift":0.02553,"hubble_type":"Sbc","wikidata_id":"Q1102292","redshift_cmb":0.026557828746446743,"discovered_by":"William Parsons, 3rd Earl of Rosse","ngc_type_code":"G","uncertainties":{"distance_ly":[20873945.660176694,20873945.660176694]},"major_axis_arcmin":0.91,"minor_axis_arcmin":0.33,"position_angle_deg":37,"surface_brightness":23.18,"radial_velocity_km_s":7556},"designations":[{"catalog":"LEDA","designation":"LEDA 28078"},{"catalog":"MCG","designation":"MCG +04-23-032"},{"catalog":"NGC","designation":"NGC 2988"},{"catalog":"PGC","designation":"PGC 28078"},{"catalog":"SDSS","designation":"SDSS J094647.91+220042.2"},{"catalog":"SDSS","designation":"SDSS J094647.97+220043.6"},{"catalog":"SDSS","designation":"SDSS J094647.97+220043.7"},{"catalog":"UGC","designation":"UGC 05233 NOTES01"}],"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."}