Delta Ursae Minoris, Latinized from δ Ursae Minoris, formally named Yildun , is a white-hued star in the northern circumpolar constellation of Ursa Minor, forming the second star in the bear's tail. It is visible to the naked eye with an apparent visual magnitude of 4.36. Based upon an annual parallax shift of 18.95 mas as seen from Earth, it is located 172 light years from the Sun. The star is moving closer to the Sun with a radial velocity of about −8 km/s.
Delta Ursae Minoris, Latinized from δ Ursae Minoris, formally named Yildun , is a white-hued star in the northern circumpolar constellation of Ursa Minor, forming the second star in the bear's tail. It is visible to the naked eye with an apparent visual magnitude of 4.36. Based upon an annual parallax shift of 18.95 mas as seen from Earth, it is located 172 light years from the Sun. The star is moving closer to the Sun with a radial velocity of about −8 km/s.
==Description== This is an A-type main-sequence star with a stellar classification of A1 Van, where the 'n' indicates "nebulous" absorption lines in the spectrum due to rapid rotation. It is spinning with a projected rotational velocity of 180 km/s, which is giving the star an oblate shape with an equatorial bulge that is an estimated 7% larger than the polar radius. The star is about 327 million years old with 2.35 times the mass of the Sun. It is radiating about 48 times the Sun's luminosity from its photosphere at an effective temperature of 9,911 K.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).