Talk:Binary star/Archive 1

Planets?

Does anyone have any ideas whether binary stars may have planets? (Have any ideas been suggested on this topic?) zoney ███ talk 00:25, 16 Aug 2004 (UTC)

PSR B1620-26 star system is a binary that has atleast one planet. You may have heard of the planet, Methuselah (planet). 132.205.15.4 02:50, 23 Sep 2004 (UTC)

Not clear

Although occasionally the individual stars that compose a binary star can be distinguished, they generally appear as one star. From the orbital pattern of a binary, the mass of its stars can be determined.

The latter seems irrelevant if the pattern can not be observed. Are the two sentences referring to different observable properties mentioned in the next section? --Patrick 12:43, Nov 9, 2004 (UTC)

Doppler Effect

Though I suppose the Doppler effect could be used to identify binary stars (an explaination how would be nice), I understood that when the stars are oriented to us such that one will eclipse the other, binaries were detected by the oscillations in apparent magnitude, rather than Doppler. Fëaluinix 00:11, 6 May 2005 (UTC)

I don't know how to edit the actual document but here is an explanation from someone who knows about a bit about the subject. The doppler shift is how much a wavelength changes due to it's radial velocity from the observer (how fast it is moving towards or away from you). If the doppler shift oscilates over are regular time period T, then you know the star is orbiting something (which makes it highly likely to be a binary with a star or blackhole or something).

Jason D. Grigsby

Spectroscopic binaries

"Systems in which the individual stars that compose a binary star can be distinguished are known as visual binaries. In systems in which the images of the individually resolved, astronomers use the Doppler shift of the spectrum to infer the presence of a binary. These systems are known as spectroscopic binaries."

The second statement is not clear.Was it suppose to be "In systems in which the images are NOT individually resolved, astronomers use the Doppler shift of the spectrum to infer the presence of a binary" or something else?

jeff mutonho

In the spectroscopic binary section, it is a bit misleading to say "...lines in the spectrum move periodically from blue to red and back again." The lines do not move that far. In fact, the shifts are quite small and are simply in one direction or the other (towards the red or blue). So, given that a particular element has a line in the yellow, a blueshifted spectrum would still have the yellow line, but shifted ever so slightly towards the blue (there is usually a base spectrum for comparison). 129.2.14.148 18:05, 14 August 2006 (UTC)Elizabeth Warner

Hello Dr. Warner and nice to see that you too have found your way to Wikipedia. Your comment is of course correct, thanks for the correction. Nick Mks 13:44, 15 August 2006 (UTC)

24 ka binary?

This was cut out recently:

A theory put forth by Walter Cruttenden in his book "Lost Star of Myth and Time" offers what many consider undeniable evidence that our local sun is in a binary or multiple star system. The theory is that our sun rotates around an unidentified cernter of mass, with a sister star, thought to be Sirius, and the orbital period of this larger orbit spans 24,000 years, give or take. More informtaion on this can be found at: http://www.binaryresearchinstitute.org/

Sounds like hogwash to me. A quick calculation shows a putative binary relationship with the Sirius system (the fifth star system in distance to the Sun!) would entail a period of the order of 224 million years. The Alpha Centauri system exerts about 2.4 times the gravity that the Sirius system does (the orbit would last 102 Ma). Without even looking up the space velocities of the stars involved, I'm certain the Sun is not bound to any of the nearby stars, if only because of the Galaxy's pervasive background gravitational field.

Urhixidur 17:37, 29 November 2005 (UTC)

Optical doubles

Odds are, though, that a double star is probably a foreground and background star pair that only looks like a binary system

This implies that optical doubles outnumber binaries. If memory serves (and the double star article agrees with me), it's the other way around. Anybody know for sure? Kanthoney 17:55, 11 January 2006 (UTC)

Good science fiction?

What about Brian Aldiss "Heliconia" series of novels? Isn't that a good example of a portrayal of a binary star system in science fiction? --212.242.162.21 12:09, 26 January 2006 (UTC)

K-PAX also needs to be mentioned, remember that he revealed the equation to solve the problem of rotation?

Disambig

Why no disambig link, for Binary Star (band)? Seems like it should be in there but I don't know how to do it.

GA Promotion

I have recently reviewed this article & found that it quite easily meets the criterion for being a good article. So I have promoted it to GA status. My congratulations to all the contributors for doing a fine job. I really feel that this is a high quality article & you should push for FA status.

Cheers

Srikeit^{(talk ¦ ✉)} 10:29, 29 May 2006 (UTC)

I have listed the article under the Astronomy section of Physics & astronomy. Although I'm not exactly sure if it is the correct subcategory. If I'm wrong please correctly re-list it. Thanks. Srikeit^{(talk ¦ ✉)} 10:39, 29 May 2006 (UTC)

• That's fine, thanks. I will indeed try to get it promoted to FA eventually, but I think it needs some work first. Nick Mks 13:09, 29 May 2006 (UTC)

Merges in 'Classifications' section

As hinted at by Worldtraveller in the FA discussion, I'm proposing a merge of the various binary star classes (seven in total) into the 'Classifications' section of this article. I personally oppose the merge, as I think that all these types deserve their own article, as they have in many other languages. I personally therefore do not see the brevity on these classifications in this article as a problem for being featured. I however want to give everybody his or her say on this. Nick Mks 19:14, 2 June 2006 (UTC)

I reconsidered the case, and maybe merging is not such a bad idea after all. The reader who searches for a specific classification then gets the general notion of a binary as well. Since no one seems to object, I carried out the merge, and provided references for these new sections. Nick Mks 19:47, 3 June 2006 (UTC)

Main Page appearance

Not to be arrogant or anything, but I have a request. Since the article Solar eclipse, which I got featured, had to endure an enourmous amout of vandalism during its appearance on the Main Page, and I vowed not to let this happen again, I have a question. Is it possible to either:

• Not let this article appear on the Main Page;
• Protect it for (at least) 24 hours if it does?

Thanks, Nick Mks 13:09, 9 June 2006 (UTC)

As it apparently is against policy to preventively (semi)protect a Featured Article of the day, I will not be attending to this article for a week starting at midnight, since I'm in no doubt that any serious editing during that time would be useless. Fingers crossed... Nick Mks 15:11, 23 June 2006 (UTC)

Verification: Real vs. fake double stars & The Formation of Binary Star Systems

I don't understand how this reference:

Formation of Binary Star Systems, University of Tennessee

verifies this paragraph:

The term 'binary star' was coined by Sir William Herschel in 1802 to designate, in his definition, "a real double star - the union of two stars that are formed together in one system by the laws of attraction". Any two closely-spaced stars might appear to be a double star, the most famous case being Mizar and Alcor in the Big Dipper. It is however possible that a double star is merely a star pair that only looks like a binary system; the two stars can in reality be widely separated in space, but just happen to lie in roughly the same direction as seen from our vantage point. Such false binaries are termed optical binaries. With the invention of the telescope, many such pairs were found. Herschel, in 1780, measured the separation and orientations of over 700 pairs that appeared to be binary systems, and found that about 50 pairs changed orientation over two decades of observation.

One is about the formation of a binary star system from a nebula, and the other is about real double stars vs. fake double stars. (The reason I noticed was that I was trying to add retrieved on dates for the references (which is helpful in case the link ever "goes dead") before this appears on the front page, and while I was at it, I was going to check if, at a glance, the links looked like they verified the material (since I was going to be adding the retrieved on dates).) Could someone explain? Armedblowfish (talk|mail|contribs) 17:22, 22 June 2006 (UTC)

You're right, this reference only covers what a binary is, not what an optical double is. I'll add an appropriate reference. Nick Mks 18:33, 22 June 2006 (UTC)

Optical Binaries

The Article says "If binaries happen to orbit in a plane perpendicular to our line of sight, it is possible for them to eclipse each other;". For rather obvious reasons i feel this to be completely wrong and later in the article i find a confirmation of this: the line of sight must lay in the orbit plane. --Wentu 07:16, 24 June 2006 (UTC)

Good call; now use your proven typng skills and go correct it! ;) --KihOshk 08:10, 24 June 2006 (UTC)

Our Sun as a Binary

Maybe the article could talk about this: http://www.binaryresearchinstitute.org/index.shtml

Spectroscopic binary definition

Sorry to be picky, but there's an apparent contradiction in the definition of a spectroscopic binary: in Terminology paragraph 3, we're told that "Binary stars that are both visual and spectroscopic binaries are rare", and not much later under Classifications: Spectroscopic Binaries we're told that "A spectroscopic binary star is a binary star which cannot be resolved as a visual binary [my italics]". Unless by 'very rare' we should understand 'non-existent'.

Sorry, that last unsigned comment was me. Jahrsper 11:04, 24 June 2006 (UTC)

Agreed - the paragraph seems to need rewriting. If the stars are visual binaries they automatically form part of the set of spectroscopic binaries. Obviously if their orbital plane is perpendicular to the observer's line of sight, no Doppler effect will be noted, but any other orientation will produce Doppler effects. Paul venter 12:38, 24 June 2006 (UTC)

You are obviously correct. The spectroscopic binary paragraph was somewhat confusing. I tried to fix it. Nick Mks 15:17, 24 June 2006 (UTC)

Binary system?

The way I heard things I binary star was just two stars with their centre of rotation being between them- they balance each other out pretty well and all. Whilst a binary system is your average solar system with 2 stars- one smaller then the other. Should there not be mention of where the line lies?--Josquius 17:44, 24 June 2006 (UTC)

• They're the same thing. — BRIAN0918 • 2006-06-24 20:59

Strange equation

   :$(m_{1}+m_{2})\cdot \left({\frac {m_{2}}{m_{1}+m_{2}}}\right)^{3}={\frac {a_{1}^{3}}{p^{3}\cdot P^{2}}}$

where:

• m₁ = mass of the star in solar masses.
• m₂ = mass of the hidden companion in solar masses.
• a₁ = semi-major axis of the star's orbit about the mass-center in seconds of arc.
• p = parallax of the binary system in seconds of arc.
• P = orbital period in years.

A quick bit of dimensional analysis gives mass on the left side and years on the right!! Something wrong here Paul venter 18:32, 24 June 2006 (UTC)

Once again, you are right. I removed the equation, as was proposed before, since a complete explanation would take too much space, and is already provided in the article on Kepler's laws of planetary motion. Nick Mks 19:07, 24 June 2006 (UTC)

First white dwarf to be discovered?

This article says:

In 1915 astronomers at the Mount Wilson Observatory determined that Sirius B was a white dwarf, the first to be discovered.

But the article 40 Eridani says:

In 1910 it was discovered that component B was actually a white dwarf star, which meant it had already evolved through its main sequence stage. In fact this was the first white dwarf star to be discovered.

The article white dwarf implies Sirius B was the first, but by the way says:

In 1917 Adriaan Van Maanen discovered Van Maanen's Star, the second known white dwarf.

Ray Spalding 05:41, 25 June 2006 (UTC)

Citation format

A really minor nit-pick, but could we get {{cite web}} formatting for the references? Titoxd^(?!?) 04:56, 13 July 2006 (UTC)