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About Tranformations, VPHOT and Landolf comp stars

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astrolopitec's picture
astrolopitec
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Joined: 2012-09-12

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

So are all these stars in M67
astrolopitec's picture
astrolopitec
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Joined: 2012-09-12

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

Landolt fields
TCB168's picture
TCB168
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Joined: 2010-07-26

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

Thank you very much Terry.
astrolopitec's picture
astrolopitec
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Joined: 2012-09-12

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

Landolt Standard Fields
FJQ's picture
FJQ
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Joined: 2010-07-25

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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