{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.852","julian_year":2026.852,"time":"2026-11-08T08:11:20.404Z","years_from_j2000":26.852,"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-108847","name":"HD 108847","class":"k4v_orange_dwarf","category":"star","object_type":"K4V orange dwarf","mag":9.08,"mag_band":"V","abs_mag":6.479,"abs_mag_band":"V","distance_ly":108.03049090730805,"distance_method":"parallax (Gaia DR3, zero point corrected)","ra_deg":187.5733806322955,"dec_deg":30.994368,"epoch_ra_deg":187.908244,"epoch_dec_deg":30.845731,"epoch_moved_arcsec":2.482,"pm_ra_mas_yr":-35.49,"pm_dec_mas_yr":85.36,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Coma Berenices","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-108847","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":{"age_years":12440877000,"mass_solar":0.763,"radius_solar":0.792,"spectral_type":"K4V","uncertainties":{"distance_ly":[0.06372467328810302,0.06379994149049611]},"color_index_bv":1.015,"luminosity_solar":0.2229671839395178,"radial_velocity_km_s":12.3,"spectral_type_source":"SIMBAD (1997JApA...18..161Y, quality C)","surface_gravity_log_g":4.547,"surface_temperature_k":4756,"proper_motion_ra_mas_yr":-35.49,"proper_motion_dec_mas_yr":85.36,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.2891},"designations":[{"catalog":"HD","designation":"HD 108847"},{"catalog":"HIP","designation":"HIP 61016"}],"updated_at":"2026-11-04T19:31:31.075Z","citation":{"plain":"SpaceCatalog. HD 108847 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-108847","bibtex":"@misc{spacecatalog_hd-108847,\n  author       = {{SpaceCatalog}},\n  title        = {{HD 108847}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-108847},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-108847","release":"DR1","doi":null},"references":[{"bibcode":"1997JApA...18..161Y","ads_url":"https://ui.adsabs.harvard.edu/abs/1997JApA...18..161Y/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."}