Talk:Albireo

message: 1.: Distance from earth: The article says "380 light-years (120 pc)" and the infobox says "430 ± 20 ly (133 ± 6 pc)". Now what?
2.: It seems User:PuzzletChung removed the distance from one star to the other in 2005. It's a shame that no one has been able to fill this in in the meantime. I would do the calculation myself if not for 1.
I help out as a guide at an observatory, and thats the first thing people ask: "How far away ist it" / "How much distance between the two". I came here today to get answers, and I'm quite surprised that apparently no one has been able to provide these yet. --BjKa (talk) 17:09, 1 November 2012 (UTC)
replies: text: That requires that one know the orbit, which we are far from knowing.  It is only possible at the present time to get a lower limit to the 3-D separation of the components, that is, the separation of their projection onto the sky plane.Donaldjbarry (talk) 04:01, 22 April 2018 (UTC)

text: 380 is an old value, I believe from the original Hipparcos parallax.  The revised Hipparcos parallax gives 430.  Note that Albireo B infoxbox still has the old value, hence it is 40 light years from its primary :)  Interestingly, the new Hipparcos reduction gives different values for the parallaxes of Alibireo A and B, slightly larger than their joint margins of error, an interesting comment on the accuracy of such things.  Fixing.  Lithopsian (talk) 17:30, 1 November 2012 (UTC)
replies: text: Note, confidence intervals are not "margins of error", but rather a statement that the true value is estimated to lie, within some probability, within the bounds stated.  The probability is not always stated and the default varies across fields, a frequent bad habit of scientific papers.  In astronomy it is usually a 1 sigma result, meaning a 68% probable confinement of the true value, assuming a normal distribution of errors.  It is not infrequent, however, that a 2 or 3 sigma result is stated, implying a 95% or 99.8% probability.  By comparison, particle physics tends to use a 5 sigma result for claims of novel detections, a 99.99998% assurance based on errors being random, which essentially means that unknown systematic effects are far more likely to effect a false detection than random error.Donaldjbarry (talk) 03:58, 22 April 2018 (UTC)
thread_title:  Distances 

message: Could someone put up a sound file as I am not sure how to pronounce it?
Jzlcdh (talk) 13:54, 15 July 2013 (UTC)
thread_title:  Pronunciation 

message: Also known as the Cub Scout star; but I'm not too sure how to edit it in without it looking like an abomination. :(  — Preceding unsigned comment added by 104.220.56.173 (talk) 01:15, 7 July 2016 (UTC)
thread_title: Cub Scout star

message: Does this star have a radius of ? If you search the size of Albireo A on the net, you always get . But where did that come from? Also, where is the actually source for jumk.de 's ?
:You're asking in the wrong place.  Wikipedia gives its sources (should do anyway), random web pages can just throw any old number out.   is calculated from a published angular diameter and a published distance.  It is unfortunate that they are published in different papers and combined only in WP, but a radius calculated from the bolometric luminosity and effective temperature is comparable.  Lithopsian (talk) 17:09, 29 November 2017 (UTC)
thread_title:  Radius 

message: A and B have different proper motions
"Star A is moving at 16.66 milliarcseconds per year south by southeast, while Star B is moving at 1.13 mas/yr west by southwest**. The uncertainties in the measurements are relatively small compared to the motion, so I'm confident in saying they're moving in two different directions at two different speeds, and therefore not physically bound together. Their alignment is coincidental."
Agmartin (talk) 19:12, 15 August 2018 (UTC)
replies: text: I wouldn't get too excited just yet.  Gaia results are (currently) notoriously unreliable for naked-eye stars because special techniques have to be applied and this hasn't been done for this data release.  Some naked-eye stars are still included where the data passes some basic sanity checks.  The primary also has a disk that is large compared to the Gaia measurements (meaning it may be observing different parts of the disk at different times), and this would need to be checked and corrected-for before any strong claims could be made.  And of course always bear in mind that the quoted margins of error are only one standard deviation, and there are potential systematic errors in addition to the quoted errors.  We need to wait for something peer-reviewed.  Lithopsian (talk) 20:09, 15 August 2018 (UTC)

text: "Taken all together" is pretty much a definition of WP:SYNTHESIS, so I removed any statements beyond the bald data that is not contained in a reliable citation.  You can speculate all you want and I'm not going to disagree with you, but our speculation can't go in the article.  Further to the previous possible reasons for caution, Albireo A is of course itself an unambiguous close binary and it is unclear what effect that has on the astrometric data.  I have added error margins lest anyone be misled about the concreteness of the distance differences.  Further, I have replaced the blog distances with more scientific values although they aren't much different.  Lithopsian (talk) 20:04, 16 August 2018 (UTC)
thread_title:  Gaia data 

message: Is there any info about Albireo Ab? The page doesn't seem to mention anything about it. Nussun05 (talk) 06:03, 17 October 2020 (UTC)
replies: text: You could read this new paper although they don't mention the star.  Even detections have been fleeting and there is little hard data on it.  WDS has a few notes, but nothing conclusive.  MSC shows an Aa/Ab orbit, but may be referring to Aa/Ac.  Lithopsian (talk) 13:37, 18 October 2020 (UTC)
thread_title:  Albireo Ab 

message: "It is not known whether the two components β Cygni A and B are orbiting around each other..." So is that still true, nothing definitive? If that's the case, is it because the distances are not known with enough certainty? Assambrew (talk) 18:15, 6 August 2023 (UTC)
replies: text: Indeed, the distances are not known sufficiently well.  They are also a long way apart, regardless of their individual distances, and it is very difficult to tell whether stars are gravitationally bound in such situations.  Lithopsian (talk) 16:59, 9 August 2023 (UTC)
replies: text: Thanks. Has anyone calculated the minimum possible distance between them, assuming that both stars are the same distance from us? Assambrew (talk) 18:25, 13 August 2023 (UTC)
replies: text: I plugged some numbers into an online calculator. Given angular separation around 35 arcseconds and approximate distance 400 light years for both stars, their minimum separation would be about 4,300 AU, or 0.068 light years. I would put that into the article if it wasn't original research :) Assambrew (talk) 17:09, 20 August 2023 (UTC)
replies: text: See this and this for sources that give a potential separation.  For example, the second paper does a trivial calculation of the average projected separation at , although they still aren't convinced that the two are bound.  Lithopsian (talk) 17:38, 20 August 2023 (UTC)
thread_title:  Jury is still out?