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About Tranformations, VPHOT and Landolf comp stars

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astrolopitec
astrolopitec's picture
About Tranformations, VPHOT and Landolf comp stars

Hi

I'm beginning to tackle the subject of Transformations so this weekend I took some nice VBR series of M67.

I uploaded one of the images into VPHOT and was surprised that it only found one comp star in the entire field. Even funnier it found 31 variables!

What gives? Am I doing something wrong?

Thanks

Juan

astrolopitec
astrolopitec's picture
So are all these stars in M67

So are all these stars in M67 really variables? Only one comp?

Makes no sense to me. But then again that's nothing new. 

http://pages.videotron.com/astrolo/buffer/M67VPHOT.jpg

Thanks

Juan

TCB168
TCB168's picture
Landolt fields

It just means that the so called standard stars in the M67 field have not been entered into the database. The variables will be real at least at the level of "suspected" variable.

If you try an actual Landolt field rather than M67, the stars will be there.

Some time ago I formatted the data and they have been entered.

A page of the fields is here

http://www.aavso.org/standard-stars-vsp

 

Cheers

Terry B

astrolopitec
astrolopitec's picture
Thank you very much Terry.

Thank you very much Terry. That was most informative. In fact your link http://www.aavso.org/standard-stars-vsp should be included in the CCD Resource and Reading List page http://www.aavso.org/ccd-resource-and-reading-list

I would also like to thank you for your work entering all the data for the "official" Landolf fields.  

Juan Herrero

FJQ
FJQ's picture
Landolt Standard Fields

Juan,

Here 's a link we used for night to night all-sky photometric reduction from landolt fields: http://www.noao.edu/wiyn/obsprog/images/tableA.html

James - FJQ

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