Stromgren photometric data in Vizier

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Discussion Overview

The discussion revolves around the availability of Stromgren photometric data, specifically the uvby magnitudes, in various catalogs. Participants are exploring the possibility of deriving these magnitudes from existing data and seeking alternative sources for the required photometric information.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant expresses interest in using a specific photometric transform but notes that the consulted catalogs only provide indices, questioning if uvby magnitudes are available elsewhere.
  • Another participant points out that SIMBAD has magnitudes in BVGJHK bands, providing a link for reference.
  • A participant acknowledges the previous mention of SIMBAD but indicates they are still searching for Stromgren uvby photometry.
  • One participant suggests that the Paunzen catalog provides enough information (v, b-y, m1) to potentially derive the desired magnitudes, questioning if V is equivalent to v.
  • Another participant clarifies that capital V likely refers to the Johnson V magnitude, not the Stromgren v.
  • Some participants express uncertainty about their contributions and the clarity of the discussion.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the availability of Stromgren uvby photometry or the equivalence of V and v. There are multiple viewpoints regarding the interpretation of the data from the catalogs discussed.

Contextual Notes

There is uncertainty regarding the definitions of the magnitudes mentioned and the completeness of the catalogs in providing the desired photometric data. The discussion includes assumptions about the relationships between different photometric indices.

yucheng
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TL;DR
Is there a catalog in Vizier that provides Stromgren photometric data for stars, (the all four uvby, not just the indices b-y, m and c)
I would like to try the photometric transform given in my book, for instance ##V = y - 0.12[(b-y) - 0.55]^2##, however, the two catalogs I've consulted, Paunzen, 2015 and Hauck, 1997 only provides the indices. Do these catalogs provide the uvby magnitudes as well, just hidden somewhere? Are there any catalogs that would provide the above photometric magnitudes? Thanks!
 
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yucheng said:
Yes I am aware of that. But...
Just thought I'd point it out. Sorry, I don't know where to find Stromgren uvby photometry.
 
Maybe I'm confused, but it looks like the Paunzen catalog gives v, b-y, and m1=(v-b)-(b-y). Can't you solve those for v, b, and y? Similarly, it gives c1=(u-v)-(v-b), so this gives you u given v, c1, and b.

Edit: Or is V not the same as v?
 
Last edited:
phyzguy said:
Just thought I'd point it out. Sorry, I don't know where to find Stromgren uvby photometry.
That's alright.
phyzguy said:
Maybe I'm confused, but it looks like the Paunzen catalog gives v, b-y, and m1=(v-b)-(b-y). Can't you solve those for v, b, and y? Similarly, it gives c1=(u-v)-(v-b), so this gives you u given v, c1, and b.

Edit: Or is V not the same as v?
I am not very sure, but I think capital V is the Johnson V, not Stromgren v:

Clicking Vmag,
Mean V magnitude
UCD:​
PHOT_JHN_V = Johnson magnitude V (JHN)
 
I think you're right. Oh well, I'm obviously not helping.
 
phyzguy said:
I think you're right. Oh well, I'm obviously not helping.
That's alright! I appreciate your effort and time! Thanks!