What is meant by an "E-region" star?

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Tue, 09/25/2018 - 18:41

. . . in particular, in the context of papers on photometric systems, such as Bessel,  Pub. ASP 112: 961-965, July 2000?  I cannot find a definition anywhere!

Thanks!

CS,

Stephen

What is meant by an "E-region" star?

Hi Stephen,

the E Regions are southern hemisphere standard star fields, I guess analogous to the Landolt fields. There are 9 E Regions evenly spaced around the sky at about -45 declination. There are also 3 F Regions at -75 declination but these generally don't get mentioned much.

Each E Region contains several dozen standard stars with well determined V, B-V, U-B, V-R and V-I magnitudes/color indices. The main reference is:

1989SAAOC..13....1M

MENZIES J.W., COUSINS A.W.J., BANFIELD R.M., and LAING J.D.

South African Astron. Obs. Circ., 13, 1-13 (1989)

UBV(RI)c standard stars in the E- and F-regions and in the Magellanic Clouds -  a revised catalogue.

You can download the paper from http://adsabs.harvard.edu/abs/1989SAAOC..13....1M

 

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Thanks, Mark!

I downloaded the catalog and have done an analysis of the non-K-M giants for which good photometry is available.  I now understand why Bessel did not include them in his paper, and why it is incorrect to attempt applying the Mamajek, et al formula to such stars.  If you're interested, contact me off line.

CS,

Stephen