{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.664","julian_year":2026.664,"time":"2026-08-31T16:35:40.025Z","years_from_j2000":26.664,"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-39748","name":"PGC 39748","class":"irregular_galaxy","category":"galaxy","object_type":"Irregular galaxy","mag":14.502,"mag_band":"B","abs_mag":-16.735625312550823,"abs_mag_band":"B","distance_ly":57670130.97210258,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":184.998032,"dec_deg":-17.391941,"epoch_ra_deg":185.345513,"epoch_dec_deg":-17.540998,"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":"Corvus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-39748","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.502,"h_mag":11.253,"j_mag":11.978,"k_mag":10.976,"redshift":0.00465,"hubble_type":"10","redshift_cmb":0.0041156825599252,"uncertainties":{"distance_ly":[4786505.033674783,4786657.933301132],"stellar_mass_solar":[560541676.878778,560541676.878778]},"major_axis_arcmin":0.463,"minor_axis_arcmin":0.361,"morphology_source":"SIMBAD (2011ApJ...733L..47F, quality D)","position_angle_deg":125,"stellar_mass_solar":1214506966.5706856},"designations":[{"catalog":"2MASX","designation":"2MASX 12195952-1723309"},{"catalog":"PGC","designation":"PGC 39748"},{"catalog":"WISExSCOS","designation":"WISExSCOS J121959.50-172331"}],"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":"2026-08-30T09:56:50.739Z","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."}