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I posted this a few days ago, but I think it got overlooked because it was at the bottom of an old thread so I'm reposting here. Just want to make sure I have calculated my transfomation coefficients correctly:

I have been working over the past few days to determine the transfomation coefficients for my system (I have a B and V filter). I realize that this is a topic that pops up periodically, so I tried to learn as much as I could from other people's experiences in the forum. I wound up imaging M67 using the process described in Priscilla Benson's paper. Attached is my excel worksheet with my results. I feel pretty confident that I did the process correctly which means I probably made a mistake. I would appreciate feedback on any glaring errors.

I am unsure of the best practice for using the coefficient information. I have already entered my values into VPhot (Tv, Tb, and Tbv). For a single target should I take 3 images in each filter, stack each group of 3, and then perform the transformation? Typically, I have used time series to get a better idea of the uncertainty, but that doesn't seem to be an option here. I just want to make sure that after having gone through the process of figuring out the coefficients I am using them correctly.

Thanks

Blake

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B-V Transformation coefficient M67 2-17-14.xlsx [1] | 20.62 KB |

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Last Updated: February 20, 2014 - 12:44pm

Last Updated: February 20, 2014 - 12:44pm

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**Links:**

[1] http://www.aavso.org/sites/default/files/B-V Transformation coefficient M67 2-17-14_1.xlsx

[2] http://www.aavso.org/forums/variable-star-observing/photometry