How true

[astroron]

How true is this statement in this article in the mailon line

Sirius is so bright because it is in fact a binary star system, two stars orbiting each other.
This is the first time I have ever heard this said
It doesn't ring true too me.
THE BRIGHTEST STAR SIRIUS
Sirius is the brightest 'star' in the night sky.
In fact it is a binary system of a white main-sequence star called Sirius A, and a faint white dwarf, Sirius B.
The Sirius binary system is 2.6 parsecs, or 8.6 light years away and is between 200 and 300 million years old.
It is composed of a white main-sequence star, which means it is converting hydrogen to helium in its core, called Sirius A, and a faint white dwarf, Sirius B.


Read more: http://www.dailymail.co.uk/sciencetech/article-3485995/Once-lifetime-shows-Sirius-Orion-stars-Taurus-constellation-perfectly-reflected-pond.html#ixzz42Y78FoNf

Cheers:thumbsup:
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[Somnium]

Clearly that is not true, Sirius would still be the brightest star in the sky without Sirius b . In fact, Sirius b is mag 8.44 , Sirius a is -1.47 and together they are -1.46. So the fact that Sirius is a double star actually makes it dimmer ... Counterintuitive

[astroron]

My thoughts exactly.
I just thought I would put it out there and see what other people come up with. :)
Cheers:thumbsup:

[Atmos]

Jupiter emits a greater flux than it absorbs so therefore it makes our star brighter to onlookers at vast distances ;)

If it works for Sirius b then it must also work for Jupiter :lol:

[julianh72]

It's just a case of a journalist not understanding what they are reading, and then making a complete hash of it when they try to paraphrase it.

The facts in the side box entitled "THE BRIGHTEST STAR SIRIUS" are all factually correct. (They may have been copied from Wikipedia: https://en.wikipedia.org/wiki/Sirius )

The following factually-correct statement appears in the fact box:

Sirius is the brightest 'star' in the night sky.
In fact it is a binary system of a white main-sequence star called Sirius A, and a faint white dwarf, Sirius B.

This has been paraphrased in the adjacent body text by erroneously adding one critical word - "because":

Sirius is so bright because it is in fact a binary star system, two stars orbiting each other.

(All of which doesn't detract from the fact that the photos which are the subject of the article are gorgeous!)

[Somnium]

I agree but it is this type of communication that fosters and perpetuates a misunderstanding of science. How many people think there is no gravity in space because the astronauts float in space or that we only use 10% of our brain ... These sorts of things are not difficult to correct during the editing process and makes science more accessible and correct

[Dave2042]

It's even simpler. The mere fact the Daily Mail has said it means it can't possibly be true.

[StuTodd]

"Sirius is so bright because it is in fact a binary star system, two stars orbiting each other"

Well no. It is the brightest star because it is so close to us and burns at 25000K or so. Alpha Centaurii is 4.4 Ly away but a G class star, 6000K, much cooler and less intrinsically bright than Sirius.

That is why astronomers mathematically push stars to 32.6 Ly away, to give the "absolute magnitude", to even things out a bit.

Stu

[julianh72]

Sirius A only burns at around 9900 K; Sirius B ("The Pup") burns at around 25,000 K, but is a much smaller white dwarf, so its total brightness is much lower than Sirius A.
https://en.wikipedia.org/wiki/Sirius

[bojan]

Well guys, to be exact, Sirius A doesn't burn at 9,000°K, it radiates at that temperature ;)
The burning occurs at much much higher temperatures but inside the star itself.

[StuTodd]

Don't know why I put "burns at 25000K", beer and forums never mix.

Stu

[bojan]

:cheers:

[julianh72]

I dunno - some of my best forum posts happen with a couple of glasses of Guinness under the belt!

Cheers!
:drink:

[StuTodd]

Yes, I should've stayed at 2 glasses...hic

:whistle:

[Atmos]

Maybe our entirely understanding of stellar astrophysics is flawed and it really does "burn" :P I mean, we've never been inside a star! Maybe underneath the plasma surface, stars are really powered by unicorns and rainbows. I dare someone to prove me wrong ;)

[StuTodd]

:drink: I'll have two of what you're on Atmos!

[janoskiss]

Bingo! :lol: