J/AJ/141/120 P Cygni Hα measurements (Richardson+, 2011)
The Hα variations of the luminous blue variable P Cygni:
discrete absorption components and the short S Doradus-phase.
Richardson N.D., Morrison N.D., Gies D.R., Markova N., Hesselbach E.N.,
Percy J.R.
<Astron. J., 141, 120 (2011)>
=2011AJ....141..120R 2011AJ....141..120R
ADC_Keywords: Stars, variable; Spectroscopy ; Photometry, H-alpha
Keywords: circumstellar matter - stars: early-type -
stars: individual (P Cyg, HD 193237) - stars: mass-loss -
stars: variables: general - stars: winds, outflows
Abstract:
P Cygni is a prototype of the luminous blue variables (or S Doradus
variables), and the star displays photometric and emission line
variability on a timescale of years (known as the "short S
Doradus-phase" variations). Here we present new high-resolution
Hα spectroscopy of P Cyg that we combine with earlier spectra
and concurrent V-band photometry to document the emission and
continuum flux variations over a 24 year time span.
Description:
We obtained 126 new spectroscopic observations of P Cygni using the
Ritter Observatory 1m telescope and echelle spectrograph between 1999
June 7 and 2007 October 30. These high resolving power (R=26000)
spectra were reduced by standard techniques with IRAF.
Objects:
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RA (2000) DE Designation(s)
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20 17 47.20 +38 01 58.6 P Cyg = HD 193237
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 64 158 Hα Measurements
spectra.dat 32 165 List of FITS spectra
fits/* . 165 *FITS continuum normalized spectra
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Note on fits/*: continuum normalized spectra used in the analysis of the DACs,
(Discrete Absorption Components) and our minimum absorption template that
was constructed (MaxI.fits). The spectra have been put onto a uniform
wavelength grid and have been corrected for telluric line n contamination
and Doppler corrected for Earth's motion. The file names include the
HJD of the observation.
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See also:
J/AJ/139/2269 : P Cyg Hα squared visibility (Balan+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.3 d HJD Heliocentric Julian Date
13- 16 F4.1 0.1nm Wnet Net adjusted Hα equivalent width (Å)
18- 21 F4.2 mag Vmag ? Averaged V band magnitude
23- 27 F5.1 0.1nm Wcorr ? Flux corrected Hα equivalent width (Å)
29- 32 F4.1 --- Ip ? Normalized peak intensity above continuum level
34- 38 F5.1 km/s FWHM Full-Width at Half-Maximum of emission portion
40- 44 F5.1 km/s DRV Relative radial velocity (1)
46- 51 F6.1 km/s RVmin Minimum flux velocity estimate
53- 58 F6.1 km/s RV.C ? Discrete Absorption Component radial velocity
60- 64 F5.2 0.1nm EW.C ? Discrete Absorption Component equivalent width
(in Angstroms)
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Note (1): Derived by cross-correlating each profile against an unweighted
average of all the spectra obtained at Ritter Observatory. We chose to
use a cross-correlation technique because this method is model-free
and is most sensitive to the steep emission line wings, resulting in a
measure similar to a FWHM bisector velocity.
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Byte-by-byte Description of file: spectra.dat
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Bytes Format Units Label Explanations
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1- 9 F9.1 d HJD ? Observation date
11- 32 A22 --- FileName Name of the spectrum file in subdirectory fits
(wavelength range: 652.8 to 660nm)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 02-Aug-2012