{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.777","julian_year":2026.777,"time":"2026-10-11T22:30:03.090Z","years_from_j2000":26.777,"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":"mirach","name":"Mirach","class":"m0_iiia_red_star","category":"star","object_type":"M0+IIIa red star","mag":2.07,"mag_band":"V","abs_mag":-1.84,"abs_mag_band":"V","distance_ly":197.43126165414313,"distance_method":"parallax","ra_deg":17.43291,"dec_deg":35.620558,"epoch_ra_deg":17.810684,"epoch_dec_deg":35.763325,"epoch_moved_arcsec":5.58,"pm_ra_mas_yr":175.59,"pm_dec_mas_yr":-112.23,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Andromeda","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/mirach","source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0","attribution":"HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.","commercial_use":"allowed"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"01097+3537","companions":[{"measured":2016,"magnitude":14.4,"components":"AB","discoverer_code":"BAR   1","separation_arcsec":30.6,"position_angle_deg":234},{"measured":2016,"magnitude":13.6,"components":"AK","discoverer_code":"DAL  39","separation_arcsec":59.1,"position_angle_deg":88},{"measured":2015,"magnitude":11.8,"components":"AD","discoverer_code":"BAR   1","separation_arcsec":65.3,"position_angle_deg":149},{"measured":2015,"magnitude":12.98,"components":"AC","discoverer_code":"BAR   1","separation_arcsec":108.4,"position_angle_deg":276},{"measured":2015,"magnitude":11.59,"components":"AF","discoverer_code":"BAR   1","separation_arcsec":141.8,"position_angle_deg":81},{"measured":2015,"magnitude":11.92,"components":"AE","discoverer_code":"BAR   1","separation_arcsec":155.2,"position_angle_deg":303},{"measured":2016,"magnitude":11.93,"components":"AG","discoverer_code":"BAR   1","separation_arcsec":206.4,"position_angle_deg":215},{"measured":2016,"magnitude":10.7,"components":"AH","discoverer_code":"BAR   1","separation_arcsec":232.5,"position_angle_deg":224},{"measured":2015,"magnitude":11.92,"components":"AI","discoverer_code":"BAR   1","separation_arcsec":335.2,"position_angle_deg":294}],"spectral_type":"M0+IIIa","uncertainties":{"metallicity_fe_h":[0.103,0.103]},"color_index_bv":1.576,"luminosity_solar":474.2419852602448,"metallicity_fe_h":-0.04,"radial_velocity_km_s":-0.8,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality B)","surface_gravity_log_g":1.55,"surface_temperature_k":3794,"metallicity_fe_h_source":"Median of 3 spectroscopic determinations in 6 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":175.59,"proper_motion_dec_mas_yr":-112.23,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"43 Beta And"},{"catalog":"Common name","designation":"Mirach"},{"catalog":"Gliese","designation":"Gl 53.3"},{"catalog":"HD","designation":"HD 6860"},{"catalog":"HIP","designation":"HIP 5447"},{"catalog":"HR","designation":"HR 337"}],"updated_at":"2026-10-01T09:42:28.932Z","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."}