{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.688","julian_year":2026.688,"time":"2026-09-09T02:37:59.992Z","years_from_j2000":26.688,"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":"psr-j1801m0857d","name":"PSR J1801-0857D","class":"millisecond_pulsar","category":"neutron_star","object_type":"Millisecond pulsar","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":28361.424149282037,"distance_method":"pulsar parallax (timing or VLBI)","ra_deg":270.4806845833333,"dec_deg":-8.956754444444444,"epoch_ra_deg":270.84858,"epoch_dec_deg":-8.957341,"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":"Ophiuchus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/psr-j1801m0857d","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"associations":"GC:NGC6517","spin_period_s":0.004226532006104215,"uncertainties":{"distance_ly":[2679.8196046565718,3304.243590207614]},"spin_period_derivative":7.52235050550028e-21,"characteristic_age_years":8902185378.114546,"dispersion_measure_pc_cm3":174.537,"spin_down_luminosity_erg_s":3.9333339080799564e+33,"surface_magnetic_field_gauss":180434193.2583021},"designations":[{"catalog":"ATNF","designation":"J1801-0857D"},{"catalog":"ATNF","designation":"PSR J1801-0857D"}],"source":{"id":"atnf","name":"ATNF Pulsar Catalogue (Manchester+ 2005)","url":"https://www.atnf.csiro.au/research/pulsar/psrcat","license":"Free to use with attribution; cite Manchester+ 2005 (2005AJ....129.1993M)"},"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."}