J/A+A/580/A64 FK Com spectra in Hα (Vida+, 2015)
Study of FK Comae Berenices:
VII. Correlating photospheric and chromospheric activity.
Vida K., Korhonen H., Ilyin I.V., Olah K., Andersen M.I., Hackman T.
<Astron. Astrophys. 580, A64 (2015)>
=2015A&A...580A..64V 2015A&A...580A..64V
ADC_Keywords: Stars, variable ; Spectroscopy
Keywords: stars: magnetic field - stars: atmospheres - stars: chromospheres -
stars: individual: FK Com - stars: late-type - stars: activity
Abstract:
We study the connection between the chromospheric and photospheric
behaviour of the active late-type star FK Comae. We use spot
temperature modelling, light curve inversion based on narrow- and
wide-band photometric measurements, Halpha observations from
1997-2010, and Doppler maps from 2004-2010 to compare the behaviour of
chromospheric and photospheric features. Investigating low-resolution
Hα spectra we find that the changes in the chromosphere seem to
happen mainly on a time scale longer than a few hours, but shorter
variations were also observed. According to the Halpha measurements
prominences are often found in the chromosphere that reach to more
than a stellar radius and are stable for weeks, and which seem to be
often, but not every time connected with dark photospheric spots. The
rotational modulation of the Hα emission seems to typically be
anticorrelated with the light curve, but we did not find convincing
evidence of a clear connection in the long-term trends of the Halpha
emission and the brightness of the star. In addition, FK Com seems to
be in an unusually quiet state in 2009-2010 with very little
chromospheric activity and low spot contrast, that might indicate the
long-term decrease of activity.
Description:
Low- and high- resolution normalized spectra of FK Comae, obtained by
the Nordic Optical Telescope (NOT) and the Kitt Peak National
Observatory (KPNO).
Objects:
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RA (2000) DE Designation(s)
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13 30 46.80 +24 13 57.8 FK Com = HD 117555
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
kpno.dat 27 49 Julian Dates for KPNO data
not-low.dat 27 54 Julian Dates for low-resolution NOT data
not.dat 27 176 Julian Dates for NOT data
sp/* . 308 *Individual spectra
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Note on sp/*: High resolution spectra from Nordic Optical Telescope using the
SOFIN high resolution spectrograph are labelled 34xNNNNN.dat,
low-resolution spectra from Nordic Optical Telescope using the SOFIN high
resolution spectrograph are labelled ibNNNNNN.dat, and
high-resolution spectra from Kitt Peak National Observatory (KPNO) are
labelled fkcNNaNN.dat.
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See also:
J/A+A/278/449 : Long-term photometry of FK Com (Jetsu+ 1993)
J/A+A/282/L9 : "flip-flop" in FK Com (Jetsu+ 1994)
J/A+AS/103/183 : UVBRI photometry of FK Com (Jetsu+ 1994)
J/A+A/374/1049 : Photometry of FK Com for 1993-2001 (Korhonen+, 2001)
J/A+A/390/179 : Study of FK Comae Berenices. IV. (Korhonen+ 2002)
J/A+A/467/229 : UBV photometry of FK Com and HD 199178 (Panov+, 2007)
J/A+A/476/881 : Differential photometry of FK Com (Korhonen+, 2007)
J/A+A/553/A40 : UBVI light curves of FK Com (Hackman+, 2013)
Byte-by-byte Description of file: kpno.dat not-low.dat not.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- FileName Spectrum file name in subdirectory sp
14- 27 F14.6 d JD Julian date of observation
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.6 0.1nm lambda [6400/6690] Wavelength (Angstrom)
13- 21 F9.6 --- RFlux Relative flux
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Acknowledgements:
Krisztian Vida, vidakris(at)gmail.com
References:
Korhonen et al., Paper I 1999A&A...346..101K 1999A&A...346..101K
Korhonen et al., Paper II 2000A&A...360.1067K 2000A&A...360.1067K
Korhonen et al., Paper III 2001A&A...374.1049K 2001A&A...374.1049K, Cat. J/A+A/374/1049
Korhonen et al., Paper IV 2002A&A...390..179K 2002A&A...390..179K, Cat. J/A+A/390/179
Korhonen et al., Paper V 2007A&A...476..881K 2007A&A...476..881K, Cat. J/A+A/476/881
Olah et al., Paper VI 2006A&A...452..303O 2006A&A...452..303O
(End) Patricia Vannier [CDS] 16-Jun-2015