{"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":"2026-09-09T09:50:47.721Z","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-j1756m2251","name":"PSR J1756-2251","class":"millisecond_pulsar","category":"neutron_star","object_type":"Millisecond pulsar","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2965.0579792431217,"distance_method":"pulsar parallax (timing or VLBI)","ra_deg":269.19430755,"dec_deg":-22.86648611111111,"epoch_ra_deg":269.601714,"epoch_dec_deg":-22.870384,"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":"Sagittarius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/psr-j1756m2251","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"binary_model":"DD","spin_period_s":0.02846158902599829,"uncertainties":{"distance_ly":[1046.4910514975725,3558.0695750917466]},"spin_period_derivative":1.0175019295572828e-18,"radio_flux_1400_mhz_mjy":1.087,"characteristic_age_years":443189986.2711082,"dispersion_measure_pc_cm3":121.2312,"spin_down_luminosity_erg_s":1.742278383008321e+33,"surface_magnetic_field_gauss":5445617969.9160795},"designations":[{"catalog":"ATNF","designation":"J1756-2251"},{"catalog":"ATNF","designation":"PSR J1756-2251"}],"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":"2026-09-09T09:14:30.178Z","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."}