What is the Most Accurate Mass for Rigel?

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Discussion Overview

The discussion centers around the varying estimates of Rigel's mass, with participants expressing frustration over discrepancies in different sources. The conversation explores the challenges of measuring the mass of distant stars and seeks to identify the most accurate value based on current scientific understanding.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Exploratory

Main Points Raised

  • Some participants note that common estimates for Rigel's mass range from 17 to 24 solar masses, with specific sources citing values of 21 ± 3, 20, and 18 solar masses.
  • Others argue that any measurement has inherent uncertainty, particularly for distant stars, and question the expectations for accuracy in these measurements.
  • A participant mentions the importance of having an accurate mass for Rigel for a calculation related to a tiering system in a battleboard context, emphasizing that even small discrepancies can significantly affect results.
  • Some participants suggest that the sources cited may not be reliable, with one asserting that Wikipedia is the only valid source due to its references to primary research papers.
  • There is a discussion about the age of various sources and whether they show consistency in their estimates, with some sources being more recent than others.

Areas of Agreement / Disagreement

Participants express disagreement regarding the most accurate mass for Rigel, with no consensus reached on a single value. There are multiple competing views on the reliability of different sources and the implications of measurement uncertainty.

Contextual Notes

Participants highlight the limitations of the sources discussed, including potential biases in older publications and the lack of primary data in some cases. The discussion reflects a range of estimates and the challenges in achieving a definitive measurement.

Who May Find This Useful

This discussion may be of interest to those involved in astrophysics, astronomy, or related fields, as well as individuals engaged in discussions or calculations that require accurate stellar mass values.

darkness626
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TL;DR
I need an accurate source for Rigel's mass.
I see so many different sources using different masses for Rigel. The most common of the bunch seem to be 17-18 solar masses. There are also a couple that give it 24 Sol masses. One astronomy book even cited it as 23, and another at 20. I cannot stand this discrepancy and would like to know what would be considered the "most accurate" mass for Rigel.
 
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What do you mean when you say you "cannot stand this discrepancy?" Do you not understand that any measurement has uncertainty? Measuring the mass of a distant star can be difficult. How accurate do you expect the measurements to be?
 
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darkness626 said:
Summary: I need an accurate source for Rigel's mass.

I see so many different sources using different masses for Rigel. The most common of the bunch seem to be 17-18 solar masses. There are also a couple that give it 24 Sol masses. One astronomy book even cited it as 23, and another at 20. I cannot stand this discrepancy and would like to know what would be considered the "most accurate" mass for Rigel.
Is there a significant spread of age in the various sources you mention? Is there a measure of consistency in the most recent?
 
phyzguy said:
What do you mean when you say you "cannot stand this discrepancy?" Do you not understand that any measurement has uncertainty? Measuring the mass of a distant star can be difficult. How accurate do you expect the measurements to be?
I am doing a relatively important calculation that requires the mass of Rigel. Using the wrong number will change the final result by a fair amount. Much more than a few decimal points.
Do you not understand that any measurement has uncertainty?
Of course I understand that all measurements have uncertainty. However not all methods are equal, some are more inaccurate than others.
How accurate do you expect the measurements to be?
They don't have to be perfect. I simply wish to know that based on modern science, what the most accurate measurement is. The one most within the margin of error for best accuracy.
 
Ophiolite said:
Is there a significant spread of age in the various sources you mention? Is there a measure of consistency in the most recent?
One such source is wikipedia, currently listing it as 21 plus or minus 3. I do not know how accurate they are. I'm not sure where Google gets their sources, so I can;t give a date. But, they say 18. I'd assume that these 2 numbers come from before 2005, which is the earliest Wikipedia included that mass. Yet another source from astronomytrek uses 17 masses, with the article being from 2016. Strangely enough, the very article that calls Rigel 17 solar masses, then calls it 24. Seriously? The source citing 20 solar masses is from 1998. Another source: Astropixels, has the star at 17 solar masses. Article was made in 2012. There was yet another source from SolarSystemQuick listing it as 18 solar masses. I'd assume it was published somewhere in the 2010s. Can't give a specific age for the article.
 
Without running down the primary sources it sounds like your sources are all relatively modern and in agreement with each other (within the range of uncertainty). You would probably get a better overall picture by doing a wide survey of relevant research papers but I'd doubt it would improve the number much.
 
darkness626 said:
One such source is wikipedia, currently listing it as 21 plus or minus 3. I do not know how accurate they are. I'm not sure where Google gets their sources, so I can;t give a date. But, they say 18. I'd assume that these 2 numbers come from before 2005, which is the earliest Wikipedia included that mass. Yet another source from astronomytrek uses 17 masses, with the article being from 2016. Strangely enough, the very article that calls Rigel 17 solar masses, then calls it 24. Seriously? The source citing 20 solar masses is from 1998. Another source: Astropixels, has the star at 17 solar masses. Article was made in 2012. There was yet another source from SolarSystemQuick listing it as 18 solar masses. I'd assume it was published somewhere in the 2010s. Can't give a specific age for the article.
Do note that you really have just one valid source here, and that is Wikipedia. It's the only one that itself provides sources for its data. The remainder of the pages don't, and as such should not be considered valid. You don't know where their values come from, and there's no way to check outside of emailing the authors. Furthermore, those pages are not affiliated with research institutions, which means it's not a good assumption that they are kept up to date and valid.
The source Wiki cites is itself not a primary one, but refers to papers by Przybilla et al. from 2005 and 2010.
 
Bandersnatch said:
Do note that you really have just one valid source here, and that is Wikipedia. It's the only one that itself provides sources for its data. The remainder of the pages don't, and as such should not be considered valid. You don't know where their values come from, and there's no way to check outside of emailing the authors. Furthermore, those pages are not affiliated with research institutions, which means it's not a good assumption that they are kept up to date and valid.
The source Wiki cites is itself not a primary one, but refers to papers by Przybilla et al. from 2005 and 2010.
It would appear that 21 solar masses is the average with plus or minus 3 being the margin of error. That probably explains why some of the sources cite it as 18 or 24. In that case, perhaps I should just use 21 as the mean.
 
darkness626 said:
I am doing a relatively important calculation that requires the mass of Rigel.
Do you mind satisfying our curiosity; what calculation is that?
 
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anorlunda said:
Do you mind satisfying our curiosity; what calculation is that?
I'm revising a part of the tiering system for Vsbattles. I was looking at the calculation that gave statistics for "baseline" Large Star level and noticed that there wasn't a source for Rigel being 23 solar masses, meanwhile most of them used 17 or 24. Since there were so many differences on the solar mass, I asked around here hoping to find an accurate number to use in the calculation.

Like I said, it's only "relatively" important since I doubt many people are interested in the affairs of a battleboard. But of course, we do rely on scientific calculations for giving characters statistics, and that means striving for accuracy.
 

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