J/A+A/626/A95 HD160305 images with SPHERE (Perrot+, 2019)
First resolved observations of a highly asymmetric debris disk around
HD 160305 with VLT/SPHERE.
Perrot C., Thebault P., Lagrange A.-M., Boccaletti A., Vigan A.,
Desidera S., Augereau J.-C., Bonnefoy M., Choquet E., Kral Q., Loh A.,
Menard F., Messina S., Olofsson J., Gratton R., Biller B., Brandner W.,
Buenzli E., Chauvin G., Cheetham A., Daemgen S., Delorme P., Feldt M.,
Lagadec E., Langlois M., Lannier J., Maire A.-L., Mesa D., Mouillet D.,
Peretti S., Janin-Potiron P., Salter G., Sissa E., Roux A., Llored M.,
Buey J.-T., Pavlov A., Weber L., Petit C.
<Astron. Astrophys. 626, A95 (2019)>
=2019A&A...626A..95P 2019A&A...626A..95P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, emission ; YSOs ; Photometry, infrared
Keywords: scattering - stars: individual: HD 160305 - methods: observational -
individual: high angular resolution - planet-disk interactions -
techniques: image processing
Abstract:
Direct imaging of debris disks gives important information about their
nature, their global morphology and allows to identify specific
structures possibly in connection with the presence of gravitational
perturbers. It is the most straightforward technique to observe
planetary systems as a whole.
We present the first resolved images of the debris disk around the
young F-type star HD 160305, detected in scattered light using the
VLT/SPHERE instrument in the near infrared.
We used a post-processing method based on Angular Differential Imaging
and synthetic images of debris disks produced with a disk modeling
code (GRaTer) to constrain the main characteristics of the disk around
HD160305. All of the point sources in the field of the IRDIS camera
were analyzed with an astrometric tool to determine whether they are
bound objects or background stars.
We detect a very inclined (∼82°) ring-like debris disk located at
a stellocentric distance of about 86au (deprojected width ∼27au). The
disk displays a brightness asymmetry between the two sides of the
major axis, as can be expected from scattering properties of dust
grains. We derive an anisotropic scattering factor g>0.5. A second
right-left asymmetry is also observed with respect to the minor axis.
We measure a surface brightness ratio of 0.73±0.18 between the
bright and the faint sides. Because of the low signal-to-noise ratio
(S/N) of the images we cannot easily discriminate between several
possible explanations for this left-right asymmetry, such as
perturbations by an unseen planet, the aftermath of the breakup of a
massive planetesimal, or the pericenter glow effect due to an
eccentric ring. Two epochs of observations allow us to reject the
companionship hypothesis for the 15 point sources present in the
field.
Description:
The fits files contains the reduced ADI SPHERE observation used in
fig 1. (TLOCI reduction in 2015 and 2016) and in fig 4. and 5. (KLIP
reduction in 2016). The images of 2016 (sphere_1.fits and
sphere_2.fits) are the mean of the two broadband H images. Images of
2015 (sphere_3.fits and sphere_4.fits) are the mean of the two
narrowband H2 and H3 images. The raw images are available on the ESO
archives and can be reduced with the ESO pipeline or the SPHERE
data-base pipeline of the SPHERE consortium :
https://sphere.osug.fr/spip.php?rubrique16
Objects:
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RA (2000) DE Designation(s)
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17 41 49.0 -50 43 28.0 HD 160305 = HIP 86598
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 140 4 List of fits images
fits/* . 4 Individual fits images
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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- 2 I2 h RAh Right Ascension of center (J2000)
4- 5 I2 min RAm Right Ascension of center (J2000)
7- 10 F4.1 s RAs Right Ascension of center (J2000)
12 A1 --- DE- Declination sign (J2000)
13- 14 I2 deg DEd Declination (J2000)
16- 17 I2 arcmin DEm Declination (J2000)
19- 22 F4.1 arcsec DEs Declination (J2000)
24- 27 I4 --- Nx Number of pixels along X-axis
29- 32 I4 --- Ny Number of pixels along Y-axis
34- 57 A24 "datime" Obs.date Observation date
59- 62 I4 Kibyte size Size of FITS file
64- 76 A13 --- FileName Name of FITS file, in subdirectory fits
78-140 A63 --- Title Title of the FITS file
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Acknowledgements:
Clement Perrot, clement.perrot(at)obspm.fr
(End) Patricia Vannier [CDS] 26-Apr-2019