{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.777","julian_year":2026.777,"time":"2026-10-11T22:30:03.829Z","years_from_j2000":26.777,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued position is carried along the great circle the object's own published motion puts it on, at a constant velocity, from the epoch that position was measured at, 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. The motion runs from position_epoch_jyear where the upstream publishes one — a timed pulsar's position belongs to the year it was timed — and from J2000 where it does not. 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-7293","name":"Helix Nebula","class":"planetary_nebula","category":"nebula","object_type":"Planetary nebula","mag":7.3,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":655,"distance_method":"literature value (curated)","ra_deg":337.4107083333334,"dec_deg":-20.837333333333333,"epoch_ra_deg":337.77829,"epoch_dec_deg":-20.699567,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Aquarius","discovered":"1824","featured":true,"url":"https://spacecatalog.org/object/ngc-7293","source":{"id":"openngc","name":"OpenNGC","url":"https://github.com/mattiaverga/OpenNGC","license":"CC-BY-SA-4.0","attribution":"OpenNGC, Mattia Verga (github.com/mattiaverga/OpenNGC). Fields derived from it stay under CC BY-SA 4.0.","commercial_use":"allowed"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":"The closest bright planetary nebula, a huge eye of glowing gas whose apparent size is half that of the full Moon.","properties":{"b_mag":7.5,"h_mag":14.49,"j_mag":14.33,"k_mag":14.55,"v_mag":7.3,"redshift":-0.00005,"wikidata_id":"Q97017154","also_known_as":["Eye of God","Eye of Sauron","The Helix"],"discovered_by":"Karl Ludwig Harding","ngc_type_code":"PN","major_axis_arcmin":16.33,"wikipedia_article":"Helix Nebula","radial_velocity_km_s":-15},"designations":[{"catalog":"Caldwell","designation":"C 63"},{"catalog":"Common name","designation":"Helix Nebula"},{"catalog":"ESO","designation":"ESO 602-022"},{"catalog":"ESO","designation":"ESO 602-22"},{"catalog":"Gliese","designation":"GJ 9785"},{"catalog":"IRAS","designation":"IRAS 22267-2102"},{"catalog":"IRAS","designation":"IRAS X2226-210"},{"catalog":"NGC","designation":"NGC 7293"},{"catalog":"PN","designation":"PN G036.1-57.1"}],"updated_at":"2026-10-01T09:42:28.932Z","attribution":"Data from SpaceCatalog.org. Each record names its upstream in `source`, with that producer's terms in `source.license`, the acknowledgement it asks for in `source.attribution`, and whether its terms allow commercial use in `source.commercial_use`; those terms govern the record, and citing SpaceCatalog does not discharge them."}