{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-06T03:44:57.884Z","years_from_j2000":26.679,"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":"pgc-2551818","name":"PGC 2551818","class":"barred_spiral_galaxy_sbb","category":"galaxy","object_type":"Barred spiral galaxy SBb","mag":16.863,"mag_band":"B","abs_mag":-17.780668040862523,"abs_mag_band":"B","distance_ly":276795791.9536187,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":180.76503,"dec_deg":56.916794,"epoch_ra_deg":181.10898,"epoch_dec_deg":56.767226,"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":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-2551818","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":16.863,"h_mag":14.137,"j_mag":14.821,"k_mag":13.9,"redshift":0.01924,"hubble_type":"SBb","redshift_cmb":0.0195267416027886,"uncertainties":{"distance_ly":[13961653.919821355,13965387.318430098],"stellar_mass_solar":[840730951.10674,840730951.10674]},"major_axis_arcmin":0.330437,"minor_axis_arcmin":0.265638,"morphology_source":"SIMBAD (2018MNRAS.473.4731K, quality D)","position_angle_deg":7,"stellar_mass_solar":1774876452.336451},"designations":[{"catalog":"2MASX","designation":"2MASX 12030360+5655004"},{"catalog":"PGC","designation":"PGC 2551818"},{"catalog":"WISExSCOS","designation":"WISExSCOS J120303.57+565500.3"}],"source":{"id":"glade_plus","name":"GLADE+ (Galaxy List for the Advanced Detector Era)","url":"https://cdsarc.cds.unistra.fr/viz-bin/cat/VII/291","license":"VizieR terms; cite Dalya+ 2022 (2022MNRAS.514.1403D)"},"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."}