J/A+A/624/A4 R CrA SPHERE and SINFONI images (Mesa+, 2019)
Exploring the R CrA environment with SPHERE:
Discovery of a new stellar companion.
Mesa D., Bonnefoy M., Gratton R., Van Der Plas G., D'Orazi V., Sissa E.,
Zurlo A., Rigliaco E., Schmidt T., Langlois M., Vigan A.,
Ubeira Gabellini M.G., Desidera S., Antoniucci S., Barbieri M.,
Benisty M., Boccaletti A., Claudi R., Fedele D., Gasparri D., Henning T.,
Kasper M., Lagrange A.-M., Lazzoni C., Lodato G., Maire A.-L.,
Manara C.F., Meyer M., Reggiani M., Samland M., Van den Ancker M.,
Chauvin G., Cheetham A., Feldt M., Hugot E., Janson M., Ligi R.,
Moller-Nilsson O., Petit C., Rickman E.L., Rigal F., Wildi F.
<Astron. Astrophys. 624, A4 (2019)>
=2019A&A...624A...4M 2019A&A...624A...4M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, emission ; Stars, pre-main sequence ; Spectrophotometry
Keywords: instrumentation: spectrographs - methods: data analysis -
techniques: imaging spectroscopy - stars: pre-main sequence -
stars: individual: R CrA
Abstract:
R Coronae Australis (R CrA) is the brightest star of the Coronet
nebula of the Corona Australis (CrA) star forming region. It has very
red colors, probably due to dust absorption and it is strongly
variable. High contrast instruments allow for an unprecedented direct
exploration of the immediate circumstellar environment of this star.
We observed R CrA with the near-IR channels (IFS and IRDIS) of SPHERE
at VLT. In this paper, we used four different epochs, three of them
from open time observations while one is from the SPHERE guaranteed
time. The data were reduced using the DRH pipeline and the SPHERE Data
Center. On the reduced data we implemented custom IDL routines with
the aim to subtract the speckle halo.We have also obtained
pupil-tracking H-band (1.45-1.85um) observations with the VLT/SINFONI
near-infrared medium-resolution (R3000) spectrograph.
A companion was found at a separation of 0.156" from the star in the
first epoch and increasing to 0.184" in the final one. Furthermore,
several extended structures were found around the star, the most
noteworthy of which is a very bright jet-like structure North-East
from the star. The astrometric measurements of the companion in the
four epochs confirm that it is gravitationally bound to the star. The
SPHERE photometry and the SINFONI spectrum, once corrected for
extinction, point toward an early M spectral type object with a mass
between 0.3 and 0.55M☉. The astrometric analysis provides
constraints on the orbit paramenters: e∼0.4, semi-major axis at
27-28au, inclination of ∼70° and a period larger than 30 years. We
were also able to put constraints of few MJup on the mass of possible
other companions down to separations of few tens of au.
Description:
R CrA was observed with SPHERE, the extreme adaptive optics
instrument operating at ESO very large telescope (VLT), in four
epochs (2015-06-10, 2016-08-10, 2018-06-19 and 2018-08-16).
In this work we also made use of observations of the R CrA system
obtained with the AO-fed integral field spectrograph SINFONI during
the night of 2018-09-11.
Objects:
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RA (2000) DE Designation(s)
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19 01 53.69 -36 57 08.1 R CrA = HIP 93449
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 130 4 List of fits images
fits/* . 4 Individual fits images
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See also:
J/A+A/350/883 : R CrA ISOCAM observations (Olofsson+, 1999)
J/A+AS/146/323 : RASS young sources around R CrA (Neuhaeuser+, 2000)
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)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 53 A24 "datime" Obs.date Observation date
55- 58 I4 Kibyte size Size of FITS file
60-101 A42 --- FileName Name of FITS file, in subdirectory fits
103-130 A28 --- Title Title of the FITS file
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Acknowledgements:
Dino Mesa, dino.mesa(at)inaf.it
(End) Patricia Vannier [CDS] 13-Feb-2019