page_title: Delta Geminorum
section_title: Properties
hierarchical_section_title: Delta Geminorum / Properties
caption_attribution_description: English: The star Wasat (magnitude 3.5) as seen next to Jupiter (magnitude −2.6) on 10 December 2013. Jupiter is roughly 280 times brighter than Wasat. Image taken with a Canon T3i mounted on a standard camera tripod using a 50mm f1.8 lens. (Exposure: f2.2, 5sec, 1600 ASA)
context_page_description: Delta Geminorum, formally named Wasat, is a triple star system in the constellation of Gemini.
context_section_description: Delta Geminorum is a subgiant star with the stellar classification F0 IV. It is about 60.5 light-years (18.5 parsecs) distant. This star has 1.57 times the mass of the Sun and is rotating rapidly with a projected rotational velocity of 129.7 km s⁻¹. The estimated age is 1.6 billion years.
  It has an apparent visual magnitude of +3.53, allowing it to be seen with the naked eye. It is 0.18 degree south of the ecliptic so it is occasionally occulted by the Moon and, rarely, by a planet; and is eclipsed by the sun from about 10-12 July. Thus the star can be viewed the whole night, crossing the sky, in mid-January. The last occultation by a planet was by Saturn on June 30, 1857, and the next will be by Venus on August 12, 2420. In 1930, the dwarf planet Pluto was discovered about 0.5° to the east of this star by American astronomer Clyde Tombaugh.
  Delta Geminorum is a triple star system. The inner components form a spectroscopic binary with a period of 6.1 years (2,238.7 days) and an orbital eccentricity of 0.3530. A cooler class K companion is not apparent to the naked eye but clearly visible in a small telescope. It orbits the inner pair with a period of 1,200 years and an eccentricity of 0.11. Although according to  its radial velocity is away from the Sun, it is actually approaching the Solar System. In about 1.1 million years, it will make its closest approach at a separation of roughly 6.7 ly (2.1 pc).
caption: Wasat is the bright star next to Jupiter.[17] Jupiter is ~280x brighter.
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