What would sirius, the brightest star in the sky being twice as large and twenty times brighter than our sun, look like in our sky at one light year away? it is now 8.7 light years away. Would it provide us with any solar light? would it look more like a sun or would it still just look like a realy realy bright star?
2007-03-20 06:24:20 · 5 answers · asked by michaeln_2006 2 in Science & Mathematics ➔ Astronomy & Space
It would just look like a very bright star
2007-03-20 06:44:20 · answer #1 · answered by xooxcable 5 · 1⤊ 0⤋
We are 8 light minutes away from the sun. If Sirius were one eighth of it current distance it would be 64 times brighter but still no where near sun-bright or even moon bright.
2007-03-20 06:32:00 · answer #2 · answered by a simple man 6 · 1⤊ 0⤋
There are two ways to answer your question.
First way.
Sirius apparent magnitude, m = -1.46
Sirius distance (your value), d = 8.7 LY
M = m - 5 log d + 7.5672
M = +1.41
where M is Sirius absolute magnitude. Now changing the distance...
d' = 1 LY
m' = M + 5 log d' - 7.5672
m' = -6.16
At a distance of one lightyear, Sirius would have an apparent magnitude of -6.16.
Second way.
Sirius distance (your value), d = 8.7 LY
Sirius luminosity, units of sun's luminosity (your value), L/Ls = 20
M = 4.75 - 2.5 log L/Ls
M = +1.50
where M is Sirius absolute magnitude. Now changing the distance...
d' = 1 LY
m' = M + 5 log d' - 7.5672
m' = -6.07
At a distance of one lightyear, Sirius would have an apparent magnitude of -6.07.
The two estimates are slightly different because your value for Sirius luminosity is not quite what would be calculated from the distance modulus formula (enter d in lightyears),
m - M = 5 log d - 7.5672
2007-03-20 07:39:54 · answer #3 · answered by Anonymous · 1⤊ 1⤋
It would be roughly 64 times brighter than it is now which is roughly 5 magnitudes. It would be a little brighter than Venus at its brightest.
2007-03-20 06:32:21 · answer #4 · answered by Gene 7 · 2⤊ 0⤋
It would still look like a star but with the luminosity of the full moon.
2007-03-20 06:32:28 · answer #5 · answered by ? 6 · 1⤊ 1⤋