J/AJ/162/150 Resolving circumstellar environment of MWC137 .II. (Kraus+, 2021)
Resolving the circumstellar environment of the Galactic Be supergiant star
MWC137.
II. Nebular kinematics and stellar variability.
Kraus M., Liimets T., Moiseev A., Sanchez Arias J.P., Nickeler D.H.,
Cidale L.S., Jones D.
<Astron. J., 162, 150-150 (2021)>
=2021AJ....162..150K 2021AJ....162..150K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, Be; Stars, supergiant; Stars, early-type;
Radial velocities; Spectra, optical
Keywords: Circumstellar matter; Early-type stars; Massive stars
Supergiant stars
Abstract:
The Galactic B[e] supergiant MWC137 is surrounded by a large-scale
optical nebula. To shed light on the physical conditions and
kinematics of the nebula, we analyze the optical forbidden emission
lines [NII] λλ6548,6583 and [SII]
λλ6716,6731 in long-slit spectra taken with ALFOSC at
the Nordic Optical Telescope. The radial velocities display a complex
behavior but, in general, the northern nebular features are
predominantly approaching while the southern ones are mostly receding.
The electron density shows strong variations across the nebula with
values spreading from about zero to ∼800cm-3. Higher densities are
found closer to MWC137 and in regions of intense emission, whereas in
regions with high radial velocities the density decreases
significantly. We also observe the entire nebula in the two [SII]
lines with the scanning Fabry-Perot interferometer attached to the 6m
telescope of the Special Astrophysical Observatory. These data reveal
a new bow-shaped feature at PA=225°-245° and a distance 80"
from MWC137. A new Hα image has been taken with the Danish 1.54m
telescope on La Silla. No expansion or changes in the nebular
morphology appear within 18.1yr. We derive a mass of 37-5+9M☉
and an age of 4.7±0.8Myr for MWC137. Furthermore, we detect a
period of 1.93d in the time series photometry collected with the TESS
satellite, which could suggest stellar pulsations. Other,
low-frequency variability is seen as well. Whether these signals are
caused by internal gravity waves in the early-type star or by
variability in the wind and circumstellar matter currently cannot be
distinguished.
Description:
Four long-slit optical spectra were obtained on 2018 November 8 with
the Nordic Optical Telescope (NOT) using the Andalucia Faint Object
Spectrograph and Camera (ALFOSC). ALFOSCs field of view (FOV) is and
the pixel scale is 0.21"/pix. We utilized Grism17 with a slit width of
0.5", covering a spectral range of 6315-6760Å with a spectral
reciprocal dispersion of 0.29Å/pix (R∼10000).
Objects:
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RA (2000) DE Designation(s) (Period)
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06 18 45.52 +15 16 52.2 MWC 137 = EM* MWC (P=1.93d)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 31 2634 Radial velocity measurements
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/AJ/140/416 : IR photometry of massive stars in the SMC (Bonanos+, 2010)
J/ApJS/188/32 : Breit-Pauli transition probabilities for SII (Tayal+, 2010)
J/A+A/537/A146 : Stellar models rotation. 0.8<M<120, Z=0.014 (Ekstrom+, 2012)
J/A+A/593/A112 : LHA 120-S 73 optical and NIR spectra (Kraus+, 2016)
J/A+A/620/A128 : Gaia DR2 study of Herbig Ae/Be stars (Vioque+, 2018)
J/AJ/157/159 : Stellar parameters for 131 Herbig Ae/Be stars (Arun+, 2019)
J/A+A/639/A81 : Variability of OB stars (Burssens+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 deg PA [0/345] Position Angle
4- 12 F9.3 0.1nm lambda [6583/6717] Laboratory wavelength, Angstroms
13- 19 F7.2 km/s RVel [-37.2/34.7] Radial velocity
20- 24 F5.2 km/s e_RVel [0.9/1] Error of RV
25- 31 F7.2 arcsec Dist [-34.2/53.4] Distance from the central star
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History:
From electronic version of the journal
References:
Kraus et al. Paper I : 2017AJ....154..186K 2017AJ....154..186K
(End) Prepared by [AAS], Coralie Fix [CDS], 15-Dec-2021