{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T18:51:31.916Z","years_from_j2000":26.684,"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":"ugc-1918","name":"UGC 1918","class":"spiral_galaxy_sbb_n","category":"galaxy","object_type":"Spiral galaxy SbB(N)","mag":14.172,"mag_band":"B","abs_mag":-20.331378757677665,"abs_mag_band":"B","distance_ly":259478648.208663,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":36.885326,"dec_deg":25.668707,"epoch_ra_deg":37.272168,"epoch_dec_deg":25.789436,"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":"Aries","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ugc-1918","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":14.172,"h_mag":10.823,"j_mag":11.577,"k_mag":10.516,"redshift":0.01696,"hubble_type":"SbB(N)","redshift_cmb":0.0183214746582607,"uncertainties":{"distance_ly":[14551081.101827478,14553533.883444514],"stellar_mass_solar":[9341525820.366716,9341525820.366716]},"major_axis_arcmin":1.69067,"minor_axis_arcmin":0.696896,"morphology_source":"SIMBAD (2020MNRAS.499.4370M, quality C)","position_angle_deg":117,"stellar_mass_solar":18683051640.733433},"designations":[{"catalog":"2MASX","designation":"2MASX 02273247+2540073"},{"catalog":"PGC","designation":"PGC 9351"},{"catalog":"WISExSCOS","designation":"WISExSCOS J022732.45+254007.3"}],"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."}