| Astronomical Observations & Research |
How bright would our Sun appear when seen from nearby stars?
Article posted: 30 December, 2003 Copyright © 2004 Abdul Ahad. All rights reserved. When viewed in the context of our current space propulsion technologies, such journeys really are the "stuff of dreams" taking many thousands of years to cross the vast distances to even our nearest stars. But I have always held a strong fascination for imagining such journeys and the alien skies that one could witness as a ship leaves our Solar System and heads out into the blackness of the gigantic interstellar void... No horror story set on Earth could ever portray a darkness deeper than that of the "great enveloping cosmic dark" which we will encounter on such travels. Having gone well beyond the orbit of Pluto, for the first one or two light years on the outbound voyage, I think we would mainly be looking back at our own distant Sun with its family of planets and the one "special" place from which we originate - called Earth. ![Artist's impression of the distant Sun seen from Pluto [Credit: Don Dixon]](pluto_sun.jpg)
An artist's impression of the Sun as viewed from the icy surface of Pluto, a tiny world on the remote edge of our solar system. The Sun's light intensity from this distance is drastically reduced, although still above that of the full moon seen from Earth. [Picture credit: Don Dixon] As the journey progresses we would see our Sun rapidly diminishing in brightness to just a bright star in the ship's rear view mirror. By the time we reach the shores of Alpha Centauri, our nearest star, the Sun will have shrunk to no more than a bright point of light. In the night skies of an imaginary planet around one of the stars of Alpha Centauri, our Sun will not even be the brightest of all the stars. That number one position in the stellar brightness league table will still be occupied by Sirius, much as it holds that top spot in the skies of Earth. I estimate our Sun will rank the 6th or 7th brightest star in the local Centaurian sky, after Alpha Centauri (A and B), Sirius, Canopus, Arcturus, Vega and Capella ! Apparent magnitudes of our Sun seen from various distances:
NOTE: I have based these calculations on the above quoted distance estimates and using an absolute magnitude constant of +4.75 for the Sun. For reference, the full Moon shines at magnitude -12.7 in our skies and Sirius, the brightest star, shines at magnitude -1.4
Astronomy Home page Copyright © 2004 Abdul Ahad. All rights reserved. 
SOME LINKS YOU MAY ENJOY The movie 'Contact' based on the novel by Carl Sagan The Drake equation The Voyager interstellar record The Arecibo radio message SETI projects
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![The night sky of a planet in the Alpha Centauri system. Notice a strange, bright yellowish star to the left of Cassiopeia? That's our Sun! It would shine at a magnitude of +0.4 (similar in brightness to the star Capella in our night sky) - [Credits: Night sky - Abdul Ahad, landscape - Dan Durda]](startwinkle.gif){kind=small}