{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.820","julian_year":2026.82,"time":"2026-10-27T08:21:40.221Z","years_from_j2000":26.82,"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":"hd-113139","name":"78 UMa","class":"f2v_yellow_white_main_sequence_star","category":"star","object_type":"F2V yellow-white main-sequence star","mag":4.93,"mag_band":"V","abs_mag":2.902,"abs_mag_band":"V","distance_ly":82.99146877915851,"distance_method":"parallax","ra_deg":195.181875,"dec_deg":56.366338,"epoch_ra_deg":195.472552,"epoch_dec_deg":56.220964,"epoch_moved_arcsec":2.907,"pm_ra_mas_yr":108.36,"pm_dec_mas_yr":2.67,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Ursa Major","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-113139","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":"13007+5622","age_years":1932168100,"companions":[{"measured":2025,"magnitude":7.88,"components":null,"discoverer_code":"BU 1082","separation_arcsec":0.5,"position_angle_deg":199}],"mass_solar":1.424,"radius_solar":1.735,"spectral_type":"F2V","color_index_bv":0.368,"luminosity_solar":6.014506519775483,"radial_velocity_km_s":-10,"spectral_type_source":"SIMBAD (2003AJ....126.2048G, quality C)","surface_gravity_log_g":4.063,"surface_temperature_k":6695,"proper_motion_ra_mas_yr":108.36,"proper_motion_dec_mas_yr":2.67,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":5.4118},"designations":[{"catalog":"Bayer/Flamsteed","designation":"78 UMa"},{"catalog":"HD","designation":"HD 113139"},{"catalog":"HIP","designation":"HIP 63503"},{"catalog":"HR","designation":"HR 4931"}],"updated_at":"2026-10-01T09:42:28.932Z","citation":{"plain":"SpaceCatalog. 78 UMa [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-113139","bibtex":"@misc{spacecatalog_hd-113139,\n  author       = {{SpaceCatalog}},\n  title        = {{78 UMa}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-113139},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-113139","release":"DR1","doi":null},"references":[{"bibcode":"2003AJ....126.2048G","ads_url":"https://ui.adsabs.harvard.edu/abs/2003AJ....126.2048G/abstract","quantity":"properties.spectral_type_source"}],"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."}