Posted by Larry Sessions in Astronomy Essentials | Brightest Stars|2 months ago
Achernar is the 9th brightest star and flattest star known. It’s famous as the southernmost bright star in the constellation Eridanus the River. Here’s why much of Earth never sees it … and how you can.
Delta Cephei doubles in brightness on a precise schedule, every 5.36 days. Its brightness changes are tied to its absolute brightness. Learn how this star helped establish the known distance scale of our galaxy and universe.
Posted by Larry Sessions in Astronomy Essentials | Brightest Stars|5 months ago
Altair is only 16.8 light-years from Earth, making it one of our closest stellar neighbors. At least 2 features of the star make it distinctive. For one thing, Altair needs only 10 hours to spin once on its axis, in contrast to roughly a month for our sun.