<p>I want to build a Machine Learning model to approximate effective temperatures of stars based on their B-V index but there aren't that many catalogues that include that. I came across the Vizier catalogue (<a href="http://vizier.u-strasbg.fr/viz-bin/VizieR-3?-source=V/19/data" rel="nofollow noreferrer">http://vizier.u-strasbg.fr/viz-bin/VizieR-3?-source=V/19/data</a>) and I wanted to be sure if that's a catalogue for individual stars that I can leverage.</p>

<p>Or, do you know what other resources could help in that regard? Or suggestions?</p>

<p>Thanks</p>

CC BY-SA 4.0
2019-01-31T22:54:06.920Z
There is more to your question than it first appears. The effect of variables/binaries, surface gravity between dwarfs and giants and the metallicity will cause additional spread in a Teff vs (B-V) color relation. [This paper](https://iopscience.iop.org/article/10.1086/301490/fulltext/) could give you some pointers into what is involved and the data sources (many of which should be in the VizieR service)
astrosnapper
CC BY-SA 4.0
2019-01-31T23:33:42.693Z
Thank you both for your input. You are right @astrosnapper, the idea is to complement the Hipparcos data with a Temperature variable that is not there. I'm not an astrophysicist/astronomist, I'm just very interested in the subject and I'm trying to play around with data visualization tools. I'm not interested in building a truly comprehensive model, but rather a close approximation. In fact, all of this started when I got into a podcast about an Introductory Astronomy course from the Ohio State U, and the professor said that the B-V index is a proxy measurement of Teff
Frank Pinto
CC BY-SA 4.0
2019-02-01T05:08:20.447Z
As a starter, if you use their Equation 2 from the paper and only keep the c0,c1,c2 & c3 terms, you could see how that compares against either the Piskunov catalog or the data source in the paper [Vizier link](http://vizier.cfa.harvard.edu/viz-bin/VizieR?-source=J/A+A/339/858)
astrosnapper
CC BY-SA 4.0
2019-02-10T03:07:34.113Z
Hi @astrosnapper, thanks once more. One final question: are all logarithms for things like log.Teff of the Piskunov using a base 10 right? I'm getting some very weird temperature readings like a star of 800 000K
Frank Pinto
CC BY-SA 4.0
2019-02-10T03:25:09.507Z
Yes, log to base 10. For reference, the Sun has $T_{eff}$=5777K and log Teff=3.76
astrosnapper
<star><temperature>
Regarding the VizierR catalogue
Frank Pinto
# Regarding the VizierR catalogue

(Asked by: username_0 on 2019-01-31)

I want to build a Machine Learning model to approximate effective temperatures of stars based on their B-V index but there aren't that many catalogues that include that. I came across the Vizier catalogue (<http://vizier.u-strasbg.fr/viz-bin/VizieR-3?-source=V/19/data>) and I wanted to be sure if that's a catalogue for individual stars that I can leverage.

Or, do you know what other resources could help in that regard? Or suggestions?

Thanks

**Tags:** star, temperature
> **Comments:**
> **username_1**: There is more to your question than it first appears. The effect of variables/binaries, surface gravity between dwarfs and giants and the metallicity will cause additional spread in a Teff vs (B-V) color relation. [This paper](https://iopscience.iop.org/article/10.1086/301490/fulltext/) could give you some pointers into what is involved and the data sources (many of which should be in the VizieR service)  
> **username_0**: Thank you both for your input. You are right @astrosnapper, the idea is to complement the Hipparcos data with a Temperature variable that is not there. I'm not an astrophysicist/astronomist, I'm just very interested in the subject and I'm trying to play around with data visualization tools. I'm not interested in building a truly comprehensive model, but rather a close approximation. In fact, all of this started when I got into a podcast about an Introductory Astronomy course from the Ohio State U, and the professor said that the B-V index is a proxy measurement of Teff  
> **username_1**: As a starter, if you use their Equation 2 from the paper and only keep the c0,c1,c2 & c3 terms, you could see how that compares against either the Piskunov catalog or the data source in the paper [Vizier link](http://vizier.cfa.harvard.edu/viz-bin/VizieR?-source=J/A+A/339/858)  
> **username_0**: Hi @astrosnapper, thanks once more. One final question: are all logarithms for things like log.Teff of the Piskunov using a base 10 right? I'm getting some very weird temperature readings like a star of 800 000K  
> **username_1**: Yes, log to base 10. For reference, the Sun has $T_{eff}$=5777K and log Teff=3.76  

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## 0 answers

