J/A+A/608/A106 HD 284149 SPHERE/IFS spectrum (Bonavita+, 2017)
Orbiting a binary: SPHERE characterisation of the HD 284149 system.
Bonavita M., D'Orazi V., Mesa D., Fontanive C., Desidera S., Messina S.,
Daemgen S., Gratton R., Vigan A., Zurlo A., Antichi J., Avenhaus H.,
Baruffolo A., Baudino J.L., Beuzit J.L., Boccaletti A., Bonnefoy M.,
Bruno P., Cascone E., Chauvin G., Claudi R.U., De Caprio V., Fantinel D.,
Farisato G., Feldt M., Galicher R., Giro E., Gry C., Hagelberg J.,
Incorvaia S., Janson M., Jaquet M., Lagrange A.M., Langlois M.,
Lannier J., Le Coroller H., Lessio L., Ligi R., Maire A.L., Meyer M.,
Menard F., Perrot C., Peretti S., Petit C., Ramos J., Roux A.,
Salasnich B., Salter G., Samland M., Scuderi S., Schlieder J., Surez M.,
Turatto M., Weber L.
<Astron. Astrophys. 608, A106 (2017)>
=2017A&A...608A.106B 2017A&A...608A.106B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Planets ; Spectroscopy
Keywords: stars: individual: HD 284149 - brown dwarfs - binaries: visual -
stars: rotation - techniques: high angular resolution
Abstract:
In this paper we present the results of the SPHERE observation of the
HD 284149 system, aimed at a more detailed characterisation of both
the primary and its brown dwarf companion.
We observed HD 284149 in the near-infrared with SPHERE, using the
imaging mode (IRDIS+IFS) and the long-slit spectroscopy mode
(IRDIS-LSS). The data were reduced using the dedicated SPHERE
pipeline, and algorithms such as PCA and TLOCI were applied to reduce
the speckle pattern.
The IFS images revealed a previously unknown low-mass (∼0.16M☉)
stellar companion (HD 294149 B) at ∼0.1", compatible with previously
observed radial velocity differences, as well as proper motion
differences between Gaia and Tycho-2 measurements. The known brown
dwarf companion (HD 284149 b) is clearly visible in the IRDIS images.
This allowed us to refine both its photometry and astrometry. The
analysis of the medium resolution IRDIS long slit spectra also allowed
a refinement of temperature and spectral type estimates. A full
reassessment of the age and distance of the system was also performed,
leading to more precise values of both mass and semi-major axis.
As a result of this study, HD 284149 ABb therefore becomes the latest
addition to the (short) list of brown dwarfs on wide circumbinary
orbits, providing new evidence to support recent claims that object in
such configuration occur with a similar frequency to wide companions
to single stars.
Description:
HD 284149 was observed with SPHERE in IRDIFS mode on 2015-10-25 and
with IRDIFS_EXT mode on 2015-11-27 as part of the SHINE (SpHere
INfrared survey for Exoplanet) GTO campaign.
Objects:
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RA (2000) DE Designation(s)
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04 06 38.80 +20 18 11.1 HD 284149 = V* V1300 Tau
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spectra.dat 34 39 HD 284149 B IFS spectrum
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Byte-by-byte Description of file: spectra.dat
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Bytes Format Units Label Explanations
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1- 8 F8.6 um lambda Wavelength
11- 21 E11.6 W/m2/um Flux Flux
24- 34 E11.6 W/m2/um e_Flux rms uncertainty on Flux
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Acknowledgements:
Mariangela Bonavita, mbonav(at)roe.ac.uk
(End) Patricia Vannier [CDS] 11-Dec-2017