A Caltech Library Service

Discovery of a point-like source and a third spiral arm in the transition disk around the Herbig Ae star MWC 758

Reggiani, M. and Christiaens, V. and Absil, O. and Mawet, D. and Huby, E. and Choquet, É. and Gomez Gonzalez, C. A. and Ruane, G. and Femenia, B. and Serabyn, E. and Matthews, K. and Barraza, M. and Carlomagno, B. and Defrère, D. and Delacroix, C. and Habraken, S. and Jolivet, A. and Karlsson, M. and Orban de Xivry, G. and Piron, P. and Surdej, J. and Vargas Catalán, E. and Wertz, O. (2018) Discovery of a point-like source and a third spiral arm in the transition disk around the Herbig Ae star MWC 758. Astronomy & Astrophysics, 611 . Art. No. A74. ISSN 0004-6361. doi:10.1051/0004-6361/201732016.

[img] PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


Context. Transition disks offer the extraordinary opportunity to look for newly born planets and to investigate the early stages of planet formation. Aim. In this context we observed the Herbig A5 star MWC 758 with the L′-band vector vortex coronagraph installed in the near-infrared camera and spectrograph NIRC2 at the Keck II telescope, with the aim of unveiling the nature of the spiral structure by constraining the presence of planetary companions in the system. Methods. Our high-contrast imaging observations show a bright (ΔL′ = 7.0 ± 0.3 mag) point-like emission south of MWC 758 at a deprojected separation of ~20 au (r = 0.′′111 ± 0.′′004) from the central star. We also recover the two spiral arms (southeast and northwest), already imaged by previous studies in polarized light, and discover a third arm to the southwest of the star. No additional companions were detected in the system down to 5 Jupiter masses beyond 0.′′6 from the star. Results. We propose that the bright L′-band emission could be caused by the presence of an embedded and accreting protoplanet, although the possibility of it being an asymmetric disk feature cannot be excluded. The spiral structure is probably not related to the protoplanet candidate, unless on an inclined and eccentric orbit, and it could be due to one (or more) yet undetected planetary companions at the edge of or outside the spiral pattern. Future observations and additional simulations will be needed to shed light on the true nature of the point-like source and its link with the spiral arms.

Item Type:Article
Related URLs:
URLURL TypeDescription
Reggiani, M.0000-0003-2911-0898
Christiaens, V.0000-0002-0101-8814
Absil, O.0000-0002-4006-6237
Mawet, D.0000-0002-8895-4735
Choquet, É.0000-0002-9173-0740
Gomez Gonzalez, C. A.0000-0003-2050-1710
Ruane, G.0000-0003-4769-1665
Barraza, M.0000-0002-9994-4284
Defrère, D.0000-0003-3499-2506
Karlsson, M.0000-0002-2011-0851
Orban de Xivry, G.0000-0002-4790-415X
Surdej, J.0000-0002-7005-1976
Wertz, O.0000-0003-3849-2285
Additional Information:© ESO 2018. Received 29 September 2017 / Accepted 30 November 2017. We would like to acknowledge the anonymous referee for the helpful comments. We thank Simon Casassus and Sebastián Perez for fruitful discussions on the spiral arms, and Farzana Meru for useful insights on disk cavities. This research was founded by the European Research Council under the European Union’s Seventh Framework Program (ERC Grant Agreement n. 337569) and by the French Community of Belgium through an ARC grant for Concerted Research Action. V.C. acknowledges support from CONICYT through CONICYT-PCHA/Doctorado Nacional/2016-21161112, and from the Millennium Science Initiative (Chilean Ministry of Economy), through grant RC130007. G.R. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1602444. E.C. acknowledges support from NASA through Hubble Fellowship grant HST-HF2-51355 awarded by STScI, operated by AURA Inc. for NASA under contract NAS5-2655. This work used data reprocessed as part of the ALICE program, which was supported by NASA through grant HST-AR-12652, HST-GO-11136, HST-GO-13855, HST-GO-1331, and STScI Director’s Discretionary Research Funds. The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.
Group:Astronomy Department
Funding AgencyGrant Number
European Research Council (ERC)337569
Communauté française de Belgique - Actions de recherche concertéeUNSPECIFIED
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)2016-21161112
Iniciativa Científica MilenioRC130007
NSF Astronomy and Astrophysics FellowshipAST-1602444
NASA Hubble FellowshipHST-HF2-51355
Space Telescope Science InstituteUNSPECIFIED
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:protoplanetary disks / planet-disk interactions / stars: pre-main sequence / stars: individual: MWC 758 (HD 36112)
Record Number:CaltechAUTHORS:20180411-114500404
Persistent URL:
Official Citation:Discovery of a point-like source and a third spiral arm in the transition disk around the Herbig Ae star MWC 758 M. Reggiani, V. Christiaens, O. Absil, D. Mawet, E. Huby, E. Choquet, C. A. Gomez Gonzalez, G. Ruane, B. Femenia, E. Serabyn, K. Matthews, M. Barraza, B. Carlomagno, D. Defrère, C. Delacroix, S. Habraken, A. Jolivet, M. Karlsson, G. Orban de Xivry, P. Piron, J. Surdej, E. Vargas Catalan and O. Wertz A&A, 611 (2018) A74 DOI:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:85757
Deposited By: George Porter
Deposited On:11 Apr 2018 20:06
Last Modified:15 Nov 2021 20:31

Repository Staff Only: item control page