{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T15:36:12.256Z","years_from_j2000":26.67,"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":"hd-91880","name":"φ² Hya","class":"m1iii_red_giant","category":"star","object_type":"M1III red giant","mag":6.01,"mag_band":"V","abs_mag":-0.818,"abs_mag_band":"V","distance_ly":756.7434613891,"distance_method":"parallax","ra_deg":159.06942,"dec_deg":-16.344326,"epoch_ra_deg":159.396954,"epoch_dec_deg":-16.483252,"epoch_moved_arcsec":0.815,"pm_ra_mas_yr":-30.43,"pm_dec_mas_yr":2.93,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Hydra","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-91880","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"10363-1621","companions":[{"measured":2016,"magnitude":12.2,"components":null,"discoverer_code":"BU 1075","separation_arcsec":3.5,"position_angle_deg":280}],"spectral_type":"M1III","color_index_bv":1.638,"luminosity_solar":185.01204347718584,"radial_velocity_km_s":16,"spectral_type_source":"SIMBAD (1988MSS...C04....0H, quality C)","proper_motion_ra_mas_yr":-30.43,"proper_motion_dec_mas_yr":2.93},"designations":[{"catalog":"Bayer/Flamsteed","designation":"Phi2 Hya"},{"catalog":"HD","designation":"HD 91880"},{"catalog":"HIP","designation":"HIP 51905"},{"catalog":"HR","designation":"HR 4156"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}