AMBER-NACO aperture-synthesis imaging of the half-obscured central star and the edge-on disk of the red giant L2 Pup
TLDR
In this paper, a near-IR aperture-synthesis imaging of the red giant L2 Pup was achieved by combining data from VLT/NACO speckle observations and long baseline interferometric observations with the AMBER instrument of the Very Large Telescope Interferometer (VLTI).Abstract:
The red giant L2 Pup started a dimming event in 1994, which is considered to be caused by the ejection of dust clouds. We present near-IR aperture-synthesis imaging of L2 Pup achieved by combining data from VLT/NACO speckle observations and long-baseline interferometric observations with the AMBER instrument of the Very Large Telescope Interferometer (VLTI). We also extracted an 8.7 micron image from the mid-IR VLTI instrument MIDI. Our aim is to spatially resolve the innermost region of the circumstellar environment. The diffraction-limited image at 2.27 micron obtained by bispectrum speckle interferometry with NACO with a spatial resolution of 57 mas shows an elongated component. The aperture-synthesis imaging combining the NACO speckle data and AMBER data (2.2--2.29 micron) with a spatial resolution of 5.6x7.3 mas further resolves not only this elongated component, but also the central star. The reconstructed image reveals that the elongated component is a nearly edge-on disk with a size of ~180x50 mas lying in the E-W direction, and furthermore, that the southern hemisphere of the central star is severely obscured by the equatorial dust lane of the disk. The angular size of the disk is consistent with the distance that the dust clouds that were ejected at the onset of the dimming event should have traveled by the time of our observations, if we assume that the dust clouds moved radially. This implies that the formation of the disk may be responsible for the dimming event. The 8.7 micron image with a spatial resolution of 220 mas extracted from the MIDI data taken in 2004 (seven years before the AMBER and NACO observations) shows an approximately spherical envelope without a signature of the disk. This suggests that the mass loss before the dimming event may have been spherical.read more
Citations
More filters
Journal ArticleDOI
Mass loss of stars on the asymptotic giant branch: Mechanisms, models and measurements
Susanne Höfner,Hans Olofsson +1 more
TL;DR: In this article, high-angular-resolution observations indicate at what distances from the stars dust condensation occurs, and they give information on the chemical composition and sizes of dust grains in the close vicinity of cool giants.
Journal ArticleDOI
ALMA observations of the nearby AGB star L2 Puppis - I. Mass of the central star and detection of a candidate planet
Pierre Kervella,Pierre Kervella,W. Homan,Anita M. S. Richards,Leen Decin,Iain McDonald,Miguel Montargès,Keiichi Ohnaka +7 more
TL;DR: In this paper, the authors used ALMA observations with very high angular resolution (18 × 15 mas) in band 7 (ν ≈ 350 GHz) to resolve the velocity profile of the molecular disk.
Journal ArticleDOI
The wonderful complexity of the Mira AB system
Sofia Ramstedt,S. Mohamed,Wouter Vlemmings,Matthias Maercker,Rodolfo Montez,Alain Baudry,E. De Beck,Michael Lindqvist,Hans Olofsson,Elizabeth Humphreys,Alain Jorissen,Franz Kerschbaum,A. Mayer,Markus Wittkowski,Nick L. J. Cox,Eric Lagadec,Marcelo L. Leal-Ferreira,Claudia Paladini,A. F. Pérez-Sánchez,Stéphane Sacuto +19 more
TL;DR: In this article, the Atacama Large Millimeter/submillimeter Array (ALMA) was used to map the CO(3-2) line emission around the Mira AB system at 0.5 resolution.
Journal ArticleDOI
Atmospheres and wind properties of non-spherical AGB stars
TL;DR: The wind-driving mechanism of asymptotic giant branch (AGB) stars is commonly attributed to a two-step process: first, gas in the stellar atmosphere is levitated by shockwaves caused by st...
Journal ArticleDOI
The curious case of II Lup: a complex morphology revealed with SAM/NACO and ALMA
Foteini Lykou,Foteini Lykou,Albert A. Zijlstra,Albert A. Zijlstra,Jacques Kluska,Jacques Kluska,Eric Lagadec,Peter G. Tuthill,Adam Avison,Barnaby Norris,Quentin A. Parker +10 more
TL;DR: In this paper, the authors presented the first-ever images of the circumstellar environment of the carbon-rich AGB star II Lup in the infrared and sub-mm wavelengths, and the discovery of the envelope's non-spherical morphology with the use of high-angular resolution imaging techniques with the sparse aperture masking mode on NACO/VLT and with ALMA.
References
More filters
Journal ArticleDOI
Validation of the new Hipparcos reduction
TL;DR: In this article, a new reduction of the Hipparcos data was published, which claimed accuracies for nearly all stars brighter than magnitude Hp = 8 to be better, by up to a factor 4, than in the original catalog.
Journal ArticleDOI
Speckle masking in astronomy: triple correlation theory and applications
TL;DR: The theory of speckle masking is presented; it makes use of triple correlations and their Fourier counterparts, the bispectra, and shows algorithms for the recovery of the object from genuine astronomical Bispectra data.
Journal ArticleDOI
Multipolar Bubbles and Jets in Low-Excitation Planetary Nebulae: Toward a New Understanding of the Formation and Shaping of Planetary Nebulae*
Raghvendra Sahai,John T. Trauger +1 more
TL;DR: In this paper, the authors used the Hubble Space Telescope Wide Field Planetary Camera 2 Hα imaging survey of young planetary nebulae (PNs) to identify high-speed collimated outflows or jets that operate during the late asymptotic galactic branch (AGB) and/or early post-AGB evolutionary phase.
Journal ArticleDOI
AMBER, the near-infrared spectro-interferometric three-telescope VLTI instrument
Romain Petrov,Fabien Malbet,Gerd Weigelt,P. Antonelli,Udo Beckmann,Y. Bresson,Alain Chelli,M. Dugué,Gilles Duvert,Sandro Gennari,L. Gluck,P. Kern,S. Lagarde,E. Le Coarer,Franco Lisi,Florentin Millour,K. Perraut,Pascal Puget,Fredrik T. Rantakyrö,S. Robbe-Dubois,A. Roussel,Piero Salinari,E. Tatulli,Gérard Zins,M. Accardo,Bram Acke,K. Agabi,E. Altariba,Brahim Arezki,Eric Aristidi,Carlo Baffa,J. Behrend,T. Blöcker,S. Bonhomme,S. Busoni,Frédéric Cassaing,J. M. Clausse,J. Colin,C. Connot,A. Delboulbe,A. Domiciano de Souza,Thomas Driebe,Philippe Feautrier,D. Ferruzzi,T. Forveille,E. Fossat,Renaud Foy,Didier Fraix-Burnet,A. Gallardo,Elisabetta Giani,C. Gil,A. Glentzlin,M. Heiden,M. Heininger,O. Hernandez Utrera,Karl-Heinz Hofmann,D. Kamm,Mario Kiekebusch,Stefan Kraus,D. Le Contel,J. M. Le Contel,T. Lesourd,Bruno Lopez,Morgan Lopez,Yves Magnard,Alessandro Marconi,G. Mars,G. Martinot-Lagarde,Philippe Mathias,Pierre Mege,J. L. Monin,D. Mouillet,Denis Mourard,E. Nussbaum,Keiichi Ohnaka,José Pacheco,C. Perrier,Yves Rabbia,S. Rebattu,François Reynaud,Andrea Richichi,Andrea Richichi,A. Robini,M. Sacchettini,Dieter Schertl,Markus Schöller,W. Solscheid,A. Spang,Ph. Stee,P. Stefanini,Michel Tallon,Isabelle Tallon-Bosc,D. Tasso,Leonardo Testi,F. Vakili,O. von der Lühe,J.-C. Valtier,Martin Vannier,N. Ventura +98 more
TL;DR: AMBER as mentioned in this paper is one of the VLTI instruments that combines up to three beams with low, moderate and high spectral resolutions in order to provide milli-arcsecond spatial resolution for compact astrophysical sources in the near-infrared wavelength domain.
Journal ArticleDOI
Modified astronomical speckle interferometry “speckle masking”
TL;DR: In this article, a simple method (speckle masking) for the reconstruction of real images from astronomical speckle photographs is described, which is applicable to a restricted class of objects that includes double stars.