{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.667","julian_year":2026.667,"time":"2026-09-01T18:32:32.169Z","years_from_j2000":26.667,"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":"m97","name":"Owl Nebula","class":"planetary_nebula","category":"nebula","object_type":"Planetary nebula","mag":9.9,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":2025.4311056209767,"distance_method":"Statistical distance scale for planetary nebulae (Stanghellini+ 2008)","ra_deg":168.69879166666666,"dec_deg":55.01902777777778,"epoch_ra_deg":169.087055,"epoch_dec_deg":54.872809,"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":"Ursa Major","discovered":"1781","featured":false,"url":"https://spacecatalog.org/object/m97","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":11.6,"j_mag":16.71,"v_mag":9.9,"redshift":0,"wikidata_id":"Q14359","discovered_by":"Pierre Méchain","ngc_type_code":"PN","major_axis_arcmin":3.58,"wikipedia_article":"Owl Nebula","distance_reference":"NGC 3587","radial_velocity_km_s":0},"designations":[{"catalog":"Common name","designation":"Owl Nebula"},{"catalog":"IRAS","designation":"IRAS 11119+5517"},{"catalog":"IRAS","designation":"IRAS F11118+5517"},{"catalog":"Messier","designation":"M 97"},{"catalog":"NGC","designation":"NGC 3587"},{"catalog":"PN","designation":"PN G148.4+57.0"},{"catalog":"SDSS","designation":"SDSS J111447.71+550108.5"}],"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."}