Undergrad Stromgren photometric data in Vizier

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SUMMARY

The discussion centers on the challenge of obtaining Stromgren photometric data, specifically the uvby magnitudes, from the Paunzen (2015) and Hauck (1997) catalogs, which primarily provide indices. Participants clarify that the Paunzen catalog includes values for v, b-y, and m1, allowing users to derive the necessary magnitudes through mathematical relationships. The distinction between the capital 'V' (Johnson V) and lowercase 'v' (Stromgren v) is also highlighted, emphasizing the importance of understanding these terms in photometric transformations.

PREREQUISITES
  • Understanding of photometric systems, specifically Stromgren and Johnson systems.
  • Familiarity with the Paunzen (2015) and Hauck (1997) catalogs.
  • Basic knowledge of photometric transformations and calculations.
  • Proficiency in using astronomical databases like SIMBAD.
NEXT STEPS
  • Research the mathematical relationships for deriving photometric magnitudes from indices in the Paunzen catalog.
  • Explore the SIMBAD database for additional photometric data in various bands.
  • Investigate other catalogs that may provide Stromgren uvby photometry.
  • Learn about the differences between Johnson and Stromgren photometric systems.
USEFUL FOR

Astronomers, astrophysicists, and researchers involved in photometric analysis and those seeking to utilize Stromgren photometric data for stellar studies.

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!