[Aavso-photometry] Re: At a crossroads and need some help RE BVRI.

Tue Jun 15 00:41:40 EDT 2004

Hi Greg, all,

Peranso currently does not support the import of data that includes color
indices for the calculation of transformation and extinction coefficients.
Sorry for that. However, you might be interested to know that version 1.11
has now been released, which includes support for the ANOVA period
determination method (of A. Schwarzenberg-Czerny), a 'recently' published
and amongst the best period determination methods. And there's more to come
...

Best regards,
Tonny

Tonny Vanmunster
CBA Belgium Observatory
http://www.cbabelgium.com
________________________________________________________
PERANSO : The Final Frontier of Period Analysis Software
http://www.peranso.com
________________________________________________________

-----Original Message-----
From: aavso-photometry-bounces at mira.aavso.org
[mailto:aavso-photometry-bounces at mira.aavso.org]On Behalf Of Greg
Crawford
Sent: zondag 13 juni 2004 4:07
To: aavso-photometry at mira.aavso.org
Cc: 'Tonny Vanmunster'
Subject: RE: [Aavso-photometry] Re: At a crossroads and need some help
RE BVRI.

Unless I'm mistaken, there is software available to handles this situation.
"Canopus" will enable you to import data that includes the magnitude in one
colour, and indices for the rest. You can then use such data to calculate
both
transformation and extinction coefficients, as well as errors.

I am not sure whether Tonny Vanmunster's software, "Peranso" does the same.

Details on "Canopus" can be found here:
http://www.minorplanetobserver.com/htms/mpocanopus.htm

Details on "Peranso" can be found here:
http://www.cbabelgium.com/

Greg

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http://www.nelsonbay.com/~gc/observatory.htm

> -----Original Message-----
> From: aavso-photometry-bounces at mira.aavso.org [mailto:aavso-photometry-
> bounces at mira.aavso.org] On Behalf Of Bill Goff
> Sent: Sunday, 13 June 2004 2:14 AM
> To: aavso-photometry at mira.aavso.org
> Subject: [Aavso-photometry] Re: At a crossroads and need some help RE
BVRI.
>
>
> On Jun 11, 2004, at 9:03 AM, aavso-photometry-request at mira.aavso.org
> wrote:
>
> > ----------------------------------------------------------------------
> >
> > Message: 1
> > Date: Thu, 10 Jun 2004 11:23:22 -0700 (PDT)
> > From: Tim Crawford <tcarchcape at yahoo.com>
> > Subject: [Aavso-photometry] At a crossroads and need some help RE
> >
> clip
>
> > I am, however, somewhat confused as to how to proceed
> > with the BRI filters using the AAVSO Charts with
> > extended sequences in that do I have to do
> > transformations first?
> >
> > The AAVSO CCD Observing manual does not address BVRI
> > (Section 5.7 is missing).  I did locate some
> > information under observing programs "BVRI CCD
> > Photometry observing program,"
> > http://www.aavso.org/observing/programs/ccd/ccdobs.shtml,
> > (which very well may be the missing Section 5.7 from
> > the CCD manual); never the less, after studying this 2
> > page discussion I am still unable, with a field chart
> > for the example, to follow completely what is going on
> > and how this can be applied to differential reduction
> > using the existing charts with extended sequences.
> >
> > Are Transformations of my filtered images required
> > when using charts with extended sequences or are the
> > transformations just required for all-sky photometry?
> >
> clip
>
> > Tim Crawford
> > Arch Cape Observatory
> > OR
> >
> > Ps-will post on several lists
> >
> >
> >
> > ------------------------------
> >
> > Message: 2
> > Date: Thu, 10 Jun 2004 14:33:36 -0400
> > From: "Walker, Gary" <Gary_Walker at Maxtor.com>
> > Subject: RE: [Aavso-photometry] At a crossroads and need some help RE
> > 	BVRI.
> >
>
> > Hello Tim
> >
> > AAVSO right now has only 8 stars that require BVRI Transformed data.
> > They are on the web page.  Among them are S Per, U Ori, VX Gem, DH Dra,
> > VX UMa, W Leo, RU Vir, and RR Boo.  You can get to them by going to the
> > web page and clicking Observing, Observing Programs, CCD, CCD BVRI.
> >
> > Optional transformed measurements are always welcome.
> >
> > Let me know if you have any other questions.
> >
> > Gary Walker
> > Chairperson
> > CCD Committee
> >
>
> I experience the same confusion about what is needed for multi-color
> photometry.  While there may be 8 charts with transformed data, there
> are many, many more that show several color indexes, B-V, etc and seem
> ripe from multi-color measurements.  While the color index may be handy
> to quickly understand type of star is it color wise, it's not very
> handy for multi-color differential photometry.  If I shoot a frame in
> V, I have comp stars with V mags.  If I then take frames of B or R etc.
> and only an index is available, I have to subtract out B-V etc to
> arrive at a B or R values for comps in order to make my differential
> measurement.  Now maybe I'm misunderstanding how I'm supposed to arrive
> at B or R values for comps, if so please correct me.  From my view
> point having to reduce data,  it seems that straight multi-color mags
> would be simpler.  I guess some folks have all this is a spread sheet
> somewhere, it just seems to be another step and more chances for error
> and time involved.
>
> But it seems to me that transformed measures are not required to do
> this level of work, recognizing that transformed measures would still
> be more desirable for the long term quality of data viewpoint.
>
> I would also agree with Tom that a clear set of instructions would be
> very helpful.
>
>
> Bill
>
>
> _______________________________________________
> Aavso-photometry mailing list
> Aavso-photometry at mira.aavso.org
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