{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.817","julian_year":2026.817,"time":"2026-10-26T13:44:23.682Z","years_from_j2000":26.817,"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":"pgc-4683721","name":"PGC 4683721","class":"galaxy","category":"galaxy","object_type":"Galaxy","mag":15.742,"mag_band":"B","abs_mag":-19.273723428027697,"abs_mag_band":"B","distance_ly":328526616.4355086,"distance_method":"luminosity distance from a spectroscopic redshift (GLADE+), flat ΛCDM with H0 = 70 km/s/Mpc","ra_deg":164.693008,"dec_deg":-48.46875,"epoch_ra_deg":164.991763,"epoch_dec_deg":-48.613109,"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":"Vela","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/pgc-4683721","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)","attribution":"Dálya et al. 2022, MNRAS 514, 1403 (2022MNRAS.514.1403D) — \"Please cite this paper when using GLADE+ data\" — via VizieR VII/291. This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France (DOI: 10.26093/cds/vizier). The original description of the VizieR service was published in 2000, A&AS 143, 23.","commercial_use":"needs_permission"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"b_mag":15.742,"h_mag":13.269,"j_mag":13.96,"k_mag":13.06,"redshift":0.02105,"redshift_cmb":0.0231147092181193,"uncertainties":{"distance_ly":[17586266.134743035,17590152.20049473],"stellar_mass_solar":[1868248882.6250496,1868248882.6250496]},"stellar_mass_solar":2802373323.9375744},"designations":[{"catalog":"2MASX","designation":"2MASX 10584632-4828075"},{"catalog":"Other","designation":"6dFJ1058464-482808"},{"catalog":"PGC","designation":"PGC 4683721"},{"catalog":"WISExSCOS","designation":"WISExSCOS J105846.44-482805.2"}],"updated_at":"2026-10-01T09:42:28.932Z","citation":{"plain":"SpaceCatalog. PGC 4683721 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/pgc-4683721","bibtex":"@misc{spacecatalog_pgc-4683721,\n  author       = {{SpaceCatalog}},\n  title        = {{PGC 4683721}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/pgc-4683721},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from GLADE+ (Galaxy List for the Advanced Detector Era).}\n}","url":"https://spacecatalog.org/object/pgc-4683721","release":"DR1","doi":null},"references":[],"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."}