J/ApJ/898/L38 VLT/SPHERE Y-band images of MWC 758 at two epochs (Ren+, 2020)
Dynamical evidence of a spiral arm-driving planet in the MWC 758 protoplanetary
disk.
Ren B., Dong R., van Holstein R.G., Ruffio J.-B., Calvin B.A., Girard J.H.,
Benisty M., Boccaletti A., Esposito T.M., Choquet E., Mawet D., Pueyo L.,
Stolker T., Chiang E., de Boer J., Debes J.H., Garufi A., Grady C.A.,
Hines D.C., Maire A.-L., Menard F., Millar-Blanchaer M.A., Perrin M.D.,
Poteet C.A., Schneider G.
<Astrophys. J., 898, L38 (2020)>
=2020ApJ...898L..38R 2020ApJ...898L..38R
ADC_Keywords: YSOs; Infrared sources
Keywords: Protoplanetary disks ; Coronagraphic imaging ;
Planetary system formation ; Orbital motion
Abstract:
More than a dozen young stars host spiral arms in their surrounding
protoplanetary disks. The excitation mechanisms of such arms are under
debate. The two leading hypotheses-companion-disk interaction and
gravitational instability (GI)-predict distinct motion for spirals. By
imaging the MWC 758 spiral arm system at two epochs spanning ∼5yr
using the SPHERE instrument on the Very Large Telescope (VLT), we test
the two hypotheses for the first time. We find that the pattern speeds
of the spirals are not consistent with the GI origin. Our measurements
further evince the existence of a faint "missing planet" driving the
disk arms. The average spiral pattern speed is 0.22±0.03/yr,
pointing to a driver at 172-14+18 au around a 1.9M☉ central
star if it is on a circular orbit. In addition, we witness
time-varying shadowing effects on a global scale that are likely
originating from an inner disk.
Description:
We observe MWC 758 at two epochs using the infrared dual-band imager
and spectrograph on SPHERE with the differential polarimetric imaging
mode at Y-band (1.04um). The first epoch is on 2015 March 4 under ESO
program 60.A-9389(A) (PI: M. Benisty; Benisty+ 2015, J/A+A/578/L6).
The second epoch is on 2019 November 18 under ESO program
104.C-0472(A) (PI: B. Ren).
Objects:
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RA (ICRS) DE Designation(s)
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05 30 27.53 +25 19 57.1 MWC 758 = HD 36112
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
files.dat 44 2 *VLT/SPHERE observations of MWC 758 spiral arms
from 2015 and 2019; FITS images from
data behind Figure 1
img/* . 2 FITS images (Fig1a = 2015 March 4 and
Fig1b = 2019 November 18)
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Note on files.dat: The values in the files correspond to the r2-scaled
surface brightness maps of the local Stokes parameter, Qφ. The
corresponding pixel scale of this image is 12.25mas. The star is
located at the center of the arrays.
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/126/2971 : UBVRI photometry of 131 Herbig Ae/Be (Vieira+, 2003)
J/ApJ/745/174 : Evolutionary models of gas-giant planets (Spiegel+, 2012)
J/A+A/578/L6 : Polarized images of MWC758 (Benisty+, 2015)
J/A+A/611/A74 : Angular differential imaging of MCW 758 (Reggiani+, 2018)
J/A+A/620/A128 : Gaia DR2 study of Herbig Ae/Be stars (Vioque+, 2018)
J/AJ/157/33 : RVel exploration of ε Eridani (Mawet+, 2019)
J/A+A/633/A82 : Disks around T Tauri stars with SPHERE. II. (Garufi+, 2020)
Byte-by-byte Description of file: files.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Target name
9- 18 A10 --- File Name of the FITS file in subdirectory "img"
20- 30 A11 "Y/M/D" Date Observation date
32- 44 A13 --- PID ESO program ID
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 10-Dec-2021