J/MNRAS/489/574 beta Pictoris 1997 and 1998 spectra (Tobin,+, 2019)
beta Pictoris: observations of the CaII H & K absorptions in 1997 and 1998.
Tobin, W., Barnes, S.I., Persson, S., Pollard, K.R.
<Mon. Not. R. Astron. Soc. 489, 574-593 (2019)>
=2019MNRAS.489..574T 2019MNRAS.489..574T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Spectroscopy
Keywords: line: profiles - circumstellar matter -
stars: individual: beta Pictoris
Abstract:
We present spectroscopy with resolution R∼33000 of the circumstellar
CaII H & K absorptions in the star beta Pictoris during 1997 and 1998.
From 1997 April onwards, both lines were observed simultaneously. A
total of 688 spectra were obtained on 95 nights in order to
characterize the lines' behaviour. Near-continuous Falling Evaporating
Body (FEB) variable absorption activity was seen, including additional
strong, blue-shifted features besides the one on 1997 June 19-20
already reported by others. Temporal coverage is more even than in the
HARPS spectra from 2004-11 that have been analysed for FEB orbital
parameters via a model of FEB evaporation. Our observations likely
encompass the 1997-98 Hill-sphere transit by beta Pic b, but we have
found no clear signature of transiting material. Lower-velocity FEB
absorptions tend to be deeper, narrower and longer lived, in
confirmation of earlier studies. The ratio of line strengths for one
absorption on 1998 November 27 is evocative of the variations expected
for a single FEB making a transit perpendicular to the stellar
rotation axis. Analysis with the evaporation model produces similar
distributions of orbital parameters to those obtained from the HARPS
observations, but when the derived orbital parameters are fed into a
model based solely on gravitational dynamics of point masses, the
predicted FEB accelerations do not agree with observed values. More
sophisticated modelling is called for. There is no convincing
intrinsic variation in the central circumstellar absorption such as
might be expected if an HI ring is responsible for the confinement of
circumstellar Ca+ ions. Our observations are available
electronically for further analysis by others.
Description:
Spectroscopy of the CaII H & K lines in beta Pictoris obtained on 95
nights between 1997 March and 1998 December as a function of air
wavelength presented in machine-readable form as well as graphically
(Figs 2-103 of the paper). Table of Gaussian fits to the absorptions
in machine- and human-readable forms. Also, spectra of the same lines
observed in 1992-93 in machine-readable form as well as graphically.
Some of these spectra were discussed in:
--Lagrange, A.-M. et al, The beta Pictoris circumstellar disk XXI.
Results from the December 1992 spectroscopic campaign Astronomy &
Astrophysics, 310, 547-563 (1996A&A...310..547L 1996A&A...310..547L), or were obtained in
connection with:
--Lagrange, A.-M. et al, The beta Pictoris circumstellar disk XXIV.
Clues to the origin of the stable gas Astronomy & Astrophysics, 330,
1091-1108 (1998A&A...330.1091L 1998A&A...330.1091L) but had not been made publicly available.
Objects:
---------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------
05 47 17.0 -51 04 04 beta Pic = HD 39060
---------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 110 2215 Gaussian fits to the observed CaII absorptions
hkrf9798.dat 16 386 Reference spectra for observations made between
1997-04-21 and 1998-12-02
sp/* . 113 Individual spectra
figures.dat 87 121 List of ps figures
fig/* . 121 Individual ps figures (spectra + table2.ps)
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See also:
J/A+A/299/557 : Light variations on Beta Pic (Lecavelier des Etangs+, 1995)
J/A+A/542/A18 : βPic Harps radial velocity data (Lagrange+, 2012)
J/A+A/607/A25 : beta Pic HARPS spectrum (Vidal-Madjar+, 2017)
J/A+A/627/A28 : beta Pic BRITE, bRing, SMEI light curves (Zwintz+, 2019)
J/ApJ/823/108 : A dust model for bet Pic from 0.58 to 870um (Ballering+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Date UTC date of observation (YYYY-MM-DD)
12- 16 A5 "h:m" Time UTC time of mid observation (hh:mm)
18- 28 F11.3 d HJD Heliocentric Julian Date of mid observation
30- 33 I4 s Texp Exposure duration
35- 40 F6.1 km/s HRV Heliocentric radial velocity of feature
42- 46 F5.1 km/s e_HRV Uncertainty in heliocentric radial velocity
48- 54 F7.1 km/s FWHM FWHM of feature
56- 60 F5.1 km/s e_FWHM Uncertainty in FWHM
63- 68 F6.3 --- pK ? Relative depth of K absorption
70- 74 F5.3 --- e_pK ? Uncertainty in pK
77- 82 F6.3 --- pH ? Relative depth of H absorption
84- 88 F5.3 --- e_pH ? Uncertainty in pH
90- 93 I4 0.1pm EWK ? Equivalent width of K absorption (mÅ)
96- 97 I2 0.1pm e_EWK ? Uncertainty in EWK (mÅ)
99-102 I4 0.1pm EWH ? Equivalent width of H absorption (mÅ)
104-105 I2 0.1pm e_EWH ? Uncertainty in EWH (mÅ)
108-110 A3 --- qual Fit quality (1)
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Note (1): Quality classification of the measured CaII absorptions as follows:
gs = Good Single: an absorption that may slightly overlap with another is
well fitted by a Gaussian profile.
gb = Good Blended: an absorption that overlaps with one-or-more others is
well fitted by a Gaussian profile. The threshold between 'single' and
'blend' is that the depth at the overlap exceeds one-third of the
maximum depth of the feature.
ps = Poorer Single: as gs, except that the spectrum is noisier and/or the
fit to a Gaussian is poorer.
pb = Poorer Blended: as gb, except that the spectrum is noisier and/or the
fit to a Gaussian is poorer.
ud = Uncertain Decomposition: the result of a fit of single or multiple
Gaussian profiles where the true nature of the feature could be
different. May be applied if the spectrum is noisy or if the absorption
is heavily blended, or if the profiles are markedly non-Gaussian; or,
for the deep circumstellar absorption, if the FWHM has been set to a
fixed value, or its optimized value depends strongly on the fitting
interval.
c = suffix added to gs, gb, ps, pb, or ud to indicate that the the feature
is the sharp, deep absorption centred on the stellar radial velocity
(the 'circumstellar' absorption).
ca = Circumstellar Affected: a weaker feature blends very strongly with the
deep circumstellar absorption, such that uncertainties in the
central-feature significantly affect (∼50%) the Gaussian parameters of
the fitted profile.
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Byte-by-byte Description of file: hkrf9798.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Line [HK] "H" if CaII H, "K" if CaII K
3- 10 F8.3 0.1nm lambda Air wavelength (Å)
12- 16 F5.3 --- Flux Flux at wavelength lambda in arbitrary units
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Date UTC date of observation (YYYY-MM-DD)
12- 19 A8 "h:m:s" Time UTC time of mid observation (hh:mm:ss)
21 A1 --- Line [HK] "H" if CaII H, "K" if CaII K
23- 26 I4 s Texp Exposure duration
28- 30 F3.1 --- Airmass Airmass of observation
32- 40 F9.4 0.1nm lambda Air wavelength (Å)
42- 51 F10.3 --- Flux Flux at wavelength lambda in arbitrary units
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Byte-by-byte Description of file: figures.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- FigName Name of the figure file in subdirectory fig
13- 74 A62 --- Title Title of the file
76- 87 A12 --- FileName Name of the associated ascii file
in subdirectory sp, if exist
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Acknowledgements:
William Tobin, william(at)tobin.fr
Retired, Univ. Canterbury, New Zealand
(End) William Tobin [Retired, Univ. Canterbury], P. Vannier [CDS] 11-Sep-2019