{"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":"2026-09-02T05:43:34.023Z","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-3568","name":"IC 3568","class":"planetary_nebula","category":"nebula","object_type":"Planetary nebula","mag":10.6,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":8930.161621884436,"distance_method":"Statistical distance scale for planetary nebulae (Stanghellini+ 2008)","ra_deg":188.27825,"dec_deg":82.56391666666666,"epoch_ra_deg":188.474411,"epoch_dec_deg":82.415705,"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":"Camelopardalis","discovered":"1900","featured":false,"url":"https://spacecatalog.org/object/ic-3568","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":12.8,"h_mag":11.4,"j_mag":11.37,"k_mag":10.84,"v_mag":10.6,"redshift":-0.000133,"wikidata_id":"Q90616042","also_known_as":["Lemon slice nebula"],"discovered_by":"Robert Grant Aitken","ngc_type_code":"PN","major_axis_arcmin":0.38,"wikipedia_article":"Lemon Slice Nebula","distance_reference":"IC 3568","radial_velocity_km_s":-40},"designations":[{"catalog":"2MASX","designation":"2MASX J12330668+8233506"},{"catalog":"HD","designation":"HD 109540"},{"catalog":"IC","designation":"IC 3568"},{"catalog":"IRAS","designation":"IRAS 12317+8250"},{"catalog":"IRAS","designation":"IRAS F12318+8250"},{"catalog":"LEDA","designation":"LEDA 41662"},{"catalog":"PGC","designation":"PGC 41662"},{"catalog":"PK","designation":"PK 123+34 1"},{"catalog":"PN","designation":"PN G123.6+34.5"},{"catalog":"UGC","designation":"UGC 7731"}],"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."}