Showing posts with label Astronomy. Show all posts
Showing posts with label Astronomy. Show all posts

Friday, September 6, 2013

Independant Guide for Reflector Telescope Buyer.

Reflector telescopes use a mirror to receive and
focus light emanating from celestial objects including those from our own solar system. Since these objects or stars are very far away from you, the light rays reaching the earth and your telescope are parallel. These fall on the mirror inside your telescope which has a parabolic profile and this facilitates in reflecting the rays to a single point. Hence they have the name reflector telescope.  In addition, as opposed to

Skywatcher refractor telescopes, they do not suffer from chromatic aberration (distortion in color) since all wavelengths get reflected from your mirror equally. Apart from this, reflector telescopes have the benefit of  being made in substantial size, they are cheaper than refractor telescopes of same size and since light is reflected rather than passing through, only one side need to be optically perfect. Regrettably, they also have some negatives. The optics may get misaligned and  they need frequent cleaning. Also, where secondary mirrors, either curved (convex) or plain, are used they may produce glare caused by bright stars.

Friday, August 30, 2013

The Solar Eclipse and Ring of Fire

Welcoming the annual solar eclipse

Americans are preparing to celebrate
the annual solar eclipse on Sunday the 20th of May. This is one of the rarest world events when the sun appears as only a thin ring behind the moon. There will be a visible path from northwestern Texas right through New Mexico. It will pass Southern Utah, California, Nevada and Oregon. The ‘special sun' will be seen on the North Pacific, South China and Japan on the 21st of May.

Jeffrey Newmark from NASA says that this is a rare event which is not to be missed: "I recommend anyone who has the chance to see this; because while they do happen occasionally, it's a fairly rare event…It's a neat thing to see." [1] The last time that it was seen in the USA was in 1994. Small crowds have flocked to Kanarraville in Utah to welcome the solar eclipse.