Overview of the 2006 RR Lyr & XZ Cyg Campaign

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Observing strategy



Observing Strategy

The previous campaign yielded data covering more than 10 Blazhko cycles (from 2 consecutive years, 5 complete cycles in 2004) of RR Lyr. The results of the 2004 campaign have been published: K. Kolenberg, H. Smith, K.D. Gazeas, A. Elmasli, M. Breger, E. Guggenberger, P. Van Cauteren, P. Lampens, P. Reegen, P.G. Niarchos, B. Albayrak, S.O. Selam, I. Özavci, and I. Aksu, 2006: The Blazhko Effect of RR Lyrae in 2003-2004, 2006, A&A 459, 577

In order to increase the amount of information provided by the observations, ideally the data have to fulfill the following criteria:

1. Data covering complete light curves and (in total) at least one complete Blazhko cycle

This is important to enable a decent Fourier analysis of the data, and to get a view on the changes of the light curve shape over the Blazhko cycle. From the previous data set, which allowed for a very detailed frequency analysis, we determined the light curve changes and changes in the Fourier parameters. We also found that the Blazhko period of RR Lyr, previously found to be 40.8 days, has become notably shorter, namely about 39 days. Also the other summer target, XZ Cyg, is known to have a changing Blazhko period (see LaCluyzé et al. 2004). It would be extremely interesting to follow up on this and see how stable the Blazhko behaviour of these stars is, because information on its stability can provide strong constraints for the models for explaining the Blazhko effect.

2. Data gathered in different photometric filters, preferable B, V and I

This should be an IMPORTANT new feature of the observations gathered within this framework. From data gathered in several filters (colours), much more information can be obtained. Colour information is also very likely to have a discriminating power in the determination of the geometry of the pulsation modes present in the star.

From theoretical calculations we determined that a combination of 3 different filters, preferably B, V and I, has the highest discriminating power. Therefore, if observers have these available, it would be great to get observations with the three filters (B, V, I). Of course, data in only one filter are still much better than no data at all!



   RR Lyr = HD 182989
      RA:19 25 27.9129 dec:+42 47 03.696

   BD+42 3334
      RA:19 25 04.766 dec:+42 41 31.27

   BD+42 3339
      RA:19 25 59.329 dec:+42 43 42.50



   XZ Cyg
      RA: 19 32 29.306 dec:+56 23 17.500

   GSC 03929-01703 -
      RA: 19 33 11.121 dec:+56 24 53.84

   GSC 03929-01811 -
      RA: 19 32 45.386 dec:+56 23 19.54


Participants / Observatories (in alfabetical order):


PB: Paul Beck (Vienna/Michelbach, Austria)

AE: Asli Elmasli (Ankara, Turkey)

AGS: Antonio Garrigos Sanchez (L'Ametlla del Vallès, Spain)

KG: Kosmas Gazeas (Athens, Greece)

KK: Katrien Kolenberg (Vienna, Austria)

AL: Andy Leitner (Vienna/Michelbach, Austria)

PL: Patricia Lampens (Beersel, Belgium)

NDU: Nermin Deniz Ulus (Ankara, Turkey)

CWR: C.W. Robertson (Kansas, US)

LS: Lukas Schmitzberger (Vienna/Michelbach, Austria)

HS: Horace Smith (Michigan, US)

PVC: Paul Van Cauteren (Beersel, Belgium)

BHO: Beersel Hills Observatory (Belgium)

vlt: Vienna Little Telescope (Austria)





Figures and preliminary results

More coming soon!


Field of view on a CCD frame for comparative photometry of RR Lyrae (Kosmas Gazeas).

XZ Cyg: photometric data gathered by Antonio Garrigos Sanchez, during 5 consecutive nights (June-July 2006), folded with the main pulsation period.


RR Lyr : photometric data gathered by Kosmas Gazeas, in June-July 2006, folded with the main pulsation period.

Observations of XZ Cyg in 3 different filters gathered by Antonio Garrigos Sanchez.



The changing Blazhko effect in XZ Cyg

LaCluyzé, Aaron ; Smith, Horace A. ; Gill, E.-M. ; Hedden, A. ; Kinemuchi, Karen ; Rosas, A. M. ; Pritzl, Barton J. ; Sharpee, Brian ; Wilkinson, Christopher ; Robinson, K. W. ; Baldwin, Marvin E. ; Samolyk, Gerard
The Astronomical Journal, Volume 127, Issue 3, pp. 1653-1663. ( AJ Homepage )

The Blazhko effect in RR Lyr in 2003-2004

K. Kolenberg, H. Smith, K.D. Gazeas, A. Elmasli, M. Breger, E. Guggenberger, P. Van Cauteren, P. Lampens, P. Reegen, P.G. Niarchos, B. Albayrak, S.O. Selam, I. Özavci, and I. Aksu
Astronomy & Astrophysics, in press ( A&A Homepage )

The Blazhko effect of RR Lyrae in 1996

Smith, Horace A. ; Church, Jennifer A. ; Fournier, Jessica ; Lisle, Jason ; Gay, Pamela ; Kolenberg, Katrien ; Carney, Bruce W. ; Dick, Ivy ; Peterson, Ruth C. ; Hakes, Brian
The Publications of the Astronomical Society of the Pacific, Volume 115, Issue 803, pp. 43-48. ( PASP Homepage )