The characteristics measured by semen analysis are only some of the factors in semen quality. One source states that 30% of men with a normal semen analysis actually have abnormal sperm function.
Wisps of dust and gas from the nebula which formed the star can also be seen. Credit: Atlas Image courtesy of 2MASS/UMass/IPAC-Caltech/NASA/NSF. Named for the first of their type observed, T Tauri stars are variable stars which show both periodic and random fluctuations in their brightnesses. They are newly-formed (< 10 million years old) low to intermediate mass stars (< 3 solar masses) with central temperatures too low for nuclear fusion to have started.
Zeta Reticuli (Zeta Ret, Î¶ Reticuli, Î¶ Ret) is a wide binary star system in the southern constellation of Reticulum. From the southern hemisphere the pair can be seen as a naked eye double star in very dark skies. Based upon parallax measurements, this system is located at a distance of about 39 light-years (12 parsecs) from the Earth. Zeta2 Reticuli is orbited by a circumstellar debris disk. Both stars are solar analogs that share similar characteristics with the Sun.