J/A+A/564/A88 L2 Pup JHKL images (Kervella+, 2014)
An edge-on translucent dust disk around the nearest AGB star L2 Puppis.
VLT/NACO spectro-imaging from 1.04 to 4.05 microns and VLTI interferometry.
Kervella P., Montarges M., Ridgway S.T., Perrin G., Chesneau O., Lacour S.,
Chiavassa A., Haubois X., Gallenne A.
<Astron. Astrophys. 564, A88 (2014)>
=2014A&A...564A..88K 2014A&A...564A..88K
ADC_Keywords: Stars, giant ; Interferometry ; Photometry, infrared
Keywords: stars: individual: HD 56096 - stars: imaging -
stars: AGB and post-AGB - circumstellar matter -
stars: mass-loss - techniques: high angular resolution
Abstract:
As the nearest known AGB star (d=64pc) and one of the brightest
(mK~-2), L2 Pup is a particularly interesting benchmark object to
monitor the final stages of stellar evolution. We report new lucky
imaging observations of this star with the VLT/NACO adaptive optics
system in twelve narrow band filters covering the 1.0-4.0 microns
wavelength range. These diffraction limited images reveal an extended
circumstellar dust lane in front of the star, that exhibits a high
opacity in the J band and becomes translucent in the H and K bands. In
the L band, extended thermal emission from the dust is detected. We
reproduce these observations using Monte-Carlo radiative transfer
modeling of a dust disk with the RADMC-3D code. We also present new
interferometric observations with the VLTI/VINCI and MIDI instruments.
We measure in the K band an upper limit to the limb-darkened angular
diameter of thetaLD=17.9±1.6mas, converting to a maximum linear
radius of R=123±14R☉. Considering the geometry of the extended
K band emission in the NACO images, this upper limit is probably close
to the actual angular diameter of the star. The position of L2 Pup in
the Herzsprung-Russell diagram indicates that this star has a mass
around 2M☉ and is probably experiencing an early stage of the
asymptotic giant branch. We do not detect any stellar companion of L2
Pup in our adaptive optics and interferometric observations, and we
attribute its apparent astrometric wobble in the Hipparcos data to
variable lighting effects on its circumstellar material. We however do
not exclude the presence of a binary companion, as the large loop
structure extending to more than 10AU to the North-East of the disk in
our L band images may be the result of interaction between the stellar
wind of L2 Pup and a hidden secondary object. The geometric
configuration that we propose, with a large dust disk seen almost
edge-on, appears particularly favorable to test and develop our
understanding of the formation of bipolar nebulae.
Description:
Image cubes containing the processed images of L2 Pup and the PSF
calibrator in the 12 narrow band filters of the VLT/NACO instrument.
Both the non-deconvolved and deconvolved versions are provided.
Objects:
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RA (2000) DE Designation(s)
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07 13 32.32 -44 38 23.1 L2 Pup = HD 56096
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 164 6 List of FITS images
fits/* . 6 Individual FITS files
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
22- 26 F5.2 mas/pix Scale [3.3/13.5] Scale of the image
28- 30 I3 pix Nx Number of pixels along X-axis
31 A1 --- --- [x]
32- 34 I3 pix Ny Number of pixels along Y-axis
35 A1 --- --- [x]
36- 37 I2 --- Nz Number of images
39- 69 A31 --- FileName Name of FITS file in subdirectory fits
71-164 A94 --- Title Title of the file
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Acknowledgements:
Pierre Kervella, pierre.kervella(at)obspm.fr
(End) Patricia Vannier [CDS] 04-Mar-2014