{"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":"2026-08-31T12:01:40.474Z","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":"m98","name":"M98","class":"intermediate_spiral_galaxy_sabb","category":"galaxy","object_type":"Intermediate spiral galaxy SABb","mag":10.84,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":183.45120833333334,"dec_deg":14.900333333333334,"epoch_ra_deg":183.793291,"epoch_dec_deg":14.75103,"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":"Coma Berenices","discovered":"1781","featured":false,"url":"https://spacecatalog.org/object/m98","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":10.82,"h_mag":7.1,"j_mag":7.82,"k_mag":6.89,"v_mag":10.84,"redshift":-0.0004,"hubble_type":"SABb","wikidata_id":"Q14361","redshift_cmb":0.0007014804217175818,"discovered_by":"Pierre Méchain","ngc_type_code":"G","major_axis_arcmin":11.04,"minor_axis_arcmin":2.66,"wikipedia_article":"Messier 98","position_angle_deg":152,"surface_brightness":23.89,"radial_velocity_km_s":-120},"designations":[{"catalog":"2MASX","designation":"2MASX J12134829+1454016"},{"catalog":"IRAS","designation":"IRAS 12112+1510"},{"catalog":"IRAS","designation":"IRAS F12112+1510"},{"catalog":"LEDA","designation":"LEDA 39028"},{"catalog":"MCG","designation":"MCG +03-31-079"},{"catalog":"Messier","designation":"M 98"},{"catalog":"NGC","designation":"NGC 4192"},{"catalog":"PGC","designation":"PGC 39028"},{"catalog":"SDSS","designation":"SDSS J121348.28+145401.6"},{"catalog":"UGC","designation":"UGC 7231"}],"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."}