========================================================================== J/A+A/506/1469 theta Cyg radial velocity variations (Desort+, 2009) The following files can be converted to FITS (extension .fit or fit.gz) elodie.dat sophie.dat ========================================================================== Query from: http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=J/A+A/506/1469 ==========================================================================
drwxr-xr-x 30 cats archive 4096 Jan 29 2012 [Up] drwxr-xr-x 2 cats archive 4096 May 12 09:59 [TAR file] -rw-r--r-- 1 cats archive 474 Dec 31 2009 .message -r--r--r-- 1 cats archive 5308 Dec 31 2009 ReadMe -r--r--r-- 1 cats archive 3094 Sep 1 2009 elodie.dat [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 5508 Sep 1 2009 sophie.dat [txt] [txt.gz] [fits] [fits.gz] [html]
Beginning of ReadMe : J/A+A/506/1469 theta Cyg radial velocity variations (Desort+, 2009) ================================================================================ Extrasolar planets and brown dwarfs around A-F type stars. VII. theta Cygni radial velocity variations: planets or stellar phenomenon? Desort M., Lagrange A.-M., Galland F., Udry S., Montagnier G., Beust H., Boisse I., Bonfils X., Bouchy F., Delfosse X., Eggenberger A., Ehrenreich D., Forveille T., Hebrard G., Loeillet B., Lovis C., Mayor M., Meunier N ., Moutou C., Pepe F., Perrier C., Pont F., Queloz D., Santos N.C., Segransan D., Vidal-Madjar A. <Astron. Astrophys. 506, 1469 (2009)> =2009A&A...506.1469D ================================================================================ ADC_Keywords: Stars, double and multiple ; Planets ; Radial velocities Keywords: techniques: radial velocities - stars: early-type - stars: planetary systems - stars: individual: theta Cygni Abstract: In the frame of the search for extrasolar planets and brown dwarfs around early-type main-sequence stars, we present the results obtained on the early F-type star theta Cygni. ELODIE and SOPHIE at Observatoire de Haute-Provence (OHP) were used to obtain 91 and 162 spectra, respectively. Our dedicated radial-velocity measurement method was used to monitor the star's radial velocities over five years. We also use complementary, high angular resolution and high-contrast images taken with PUEO at CFHT. We show that theta Cygni radial velocities are quasi-periodically variable, with a 150-day period. These variations are not due to the 0.35M_sun_ stellar companion that we detected in imaging at more than 46AU from the star. The absence of correlation between the bisector velocity span variations and the radial velocity variations for this 7km/s vsini star, as well as other criteria indicate that the observed radial velocity variations are not due to stellar spots. The observed amplitude of the bisector velocity span variations also seems to rule out stellar pulsations. However, we observe a peak in the bisector velocity span periodogram at the same period as the one found in the radial velocity periodogram, which indicates a probable link between these radial velocity variations and the low amplitude lineshape variations which are of stellar origin. Long-period variations are not expected from this type of star to our knowledge. If a stellar origin (hence of new type) was to be confirmed for these long-period radial velocity variations, this would have several consequences on the search for planets around main-sequence stars, both in terms of observational strategy and data analysis. An alternative explanation for these variable radial velocities is the presence of at least one planet of a few Jupiter masses orbiting at less than 1AU; however this planet alone does not explain all observed features, and the theta Cygni system is obviously more complex than a planetary system with 1 or 2 planets. The available data do not allow to distinguish between these two possible origins. A vigourous follow-up in spectroscopy and photometry is needed to get a comprehensive view of the star intrinsic variability and/or its surrounding planetary system. Objects: ---------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------- 19 36 26.5 +50 13 16 theta Cyg = HR 7469 ----------------------------------------------
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