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.
Proxima is the closest star to Earth. Faint red Proxima Centauri â at only 3,100 K and 500 times less bright than our sun â is nearly a fifth of a light year from Alpha Centauri A and B. This great distance is what calls into question its status as part of a triple star system.ottom line: The Alpha Centauri system is the closest star system to our sun. On our skyâs dome, we see this multiple system as a single star â the third-brightest star visible from Earth. Charts, photos and info about this fascinating star system.