{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.674","julian_year":2026.674,"time":"2026-09-04T00:41:57.045Z","years_from_j2000":26.674,"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-3555917","name":"PGC 3555917","class":"galaxy","category":"galaxy","object_type":"Galaxy","mag":16.45,"mag_band":"B","abs_mag":-18.053695082084612,"abs_mag_band":"B","distance_ly":259516449.93610278,"distance_method":"luminosity distance from a photometric redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":202.104,"dec_deg":11.79017,"epoch_ra_deg":202.43676,"epoch_dec_deg":11.650952,"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":"Virgo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-3555917","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":16.45,"h_mag":13.168,"j_mag":13.823,"k_mag":12.905,"redshift":0.020103940052,"redshift_cmb":0.0183241079468961,"uncertainties":{"distance_ly":[58590781.86496849,58922672.098519765],"stellar_mass_solar":[2802457718.3663483,2802457718.3663483]},"stellar_mass_solar":5604915436.732697},"designations":[{"catalog":"2MASX","designation":"2MASX 13282493+1147248"},{"catalog":"Other","designation":"2MASXJ13282493+1147248"},{"catalog":"PGC","designation":"PGC 3555917"},{"catalog":"WISExSCOS","designation":"WISExSCOS J132824.93+114724.4"}],"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."}