Period uncertanties

American Association of Variable Star Observers (AAVSO)
Sun, 06/20/2021 - 12:25

Hello All, 


I am completing some data analysis on a variable star and have good results finding the period.

However, can I get a period uncertainty (+/- ...days) in V-Star?

Any help is greatly appreciated.

Thank you


Astronomical Society of South Australia (ASSAU)
Period Uncertainty

Hi John

That's not currently implemented in VStar. The DCDFT implementation is a port of Fortran code, which as far as I'm aware, does not provide this information either.

Other than drawing some conclusions based upon the resolution specified in the DCDFT parameters dialog or using the Current Mode ANOVA plugin (or use the AoV period search plugin and compare results with DCDFT), there is no intrinsic uncertainty information available.

A similar question has been raised in the past about polynomial fit in this forum. Right now, AIC, BIC, RMS and ANOVA can be applied for polyfit but again there's no intrinsic uncertainty information available. 

I would welcome input from you or others in AAVSO re: the best way(s) to implement uncertainty analysis this for DCDFT and polynomial fit. I don't claim to have particular expertise in that area but I'm willing to learn. Brad Walter, for example, may well have specific thoughts about this.


American Association of Variable Star Observers (AAVSO)
Thank you David

Thank you and apologies for the slow reply. i just realised I hadn't subscribed to this thread. 

I'll run the data through the different methods and see what I find.