help

Why Do Pictures of Stars From Space Telescopes Appear Point-Like Rather Than Round?

-- | May 6, 2018

Question: Can you get a video image of a twinkling star in space? Also if stars do not twinkle in Space why are the pictures of them from space telescopes always pointy instead of round circles? — John

Answer: As you surmised, stars twinkle when viewed from the Earth’s surface because the motions of the Earth’s atmosphere cause the light from the star to shift as it passes through the Earth’s atmosphere. Pictures from space telescopes are not affected by the Earth’s atmosphere, so the stars appear point-like. Since stars are far away, they are in general not resolved in space telescope measurements. This is why pictures of stars appear point-like.

Jeff Mangum

Facebook
Pinterest
Twitter
Linkedin

The National Radio Astronomy Observatory is a facility of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
	Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.
	The U.S. National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."
	AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.