June's Sky Notes: Circumpolar Constellations, Part III Unveiled miragenews.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from miragenews.com Daily Mail and Mail on Sunday newspapers.
Stopping down a telescope to reduce brightness by 5 magnitudes - Astronomy gsusigmanu.org - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from gsusigmanu.org Daily Mail and Mail on Sunday newspapers.
Out of the hundreds of thousands of stars that vary in brightness only a comparatively few, such as Algol or Mira, exhibit their light variations to the unaided eye. One such star is a modestly bright star called Delta Cephei.