scholarly journals Are the Dyson rings around pulsars detectable?

2017 ◽  
Vol 17 (2) ◽  
pp. 112-115 ◽  
Author(s):  
Z. Osmanov
Keyword(s):  
Neutron Star ◽  
Solar System ◽  
Spherical Shell ◽  
Angular Resolution ◽  
Wide Field ◽  
Large Telescope ◽  
Very Large Telescope ◽  
Freeman Dyson ◽  
Infrared Survey

AbstractIn the previous paper ring (Osmanov 2016) (henceforth Paper-I) we have extended the idea of Freeman Dyson and have shown that a supercivilization has to use ring-like megastructures around pulsars instead of a spherical shell. In this work we reexamine the same problem in the observational context and we show that facilities of modern infrared (IR) telescopes (Very Large Telescope Interferometer and Wide-field Infrared Survey Explorer (WISE)) might efficiently monitor the nearby zone of the solar system and search for the IR Dyson-rings up to distances of the order of 0.2 kpc, corresponding to the current highest achievable angular resolution, 0.001 mas. In this case the total number of pulsars in the observationally reachable area is about 64 ± 21. We show that pulsars from the distance of the order of ~ 1 kpc are still visible for WISE as point-like sources but in order to confirm that the object is the neutron star, one has to use the ultraviolet telescopes, which at this moment cannot provide enough sensitivity.

scholarly journals Lite: The Large Imaging Telescope

1994 ◽  
Vol 161 ◽  
pp. 73-76
Author(s):  
L. Vigroux
Keyword(s):  
Wide Field ◽  
Large Telescope ◽  
Very Large Telescope ◽  
Imaging Telescope ◽  
Field Imaging ◽  
Wide Field Imaging

It was realised very early in the development of the ESO 16 metre equivalent Very Large Telescope (VLT) that wide-field imaging is too complicated and costly to implement on the VLT itself and should be done with a smaller telescope.

scholarly journals On the origin of Supergiant Fast X-ray Transients

2018 ◽  
Vol 14 (S346) ◽  
pp. 193-196
Author(s):  
Swetlana Hubrig ◽  
Lara Sidoli ◽  
Konstantin A. Postnov ◽  
Markus Schöller ◽  
Alexander F. Kholtygin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Stellar Wind ◽  
Longitudinal Magnetic Field ◽  
High Mass ◽  
Large Telescope ◽  
X Ray ◽  
Very Large Telescope ◽  
Low X ◽  
X Ray Binaries

Abstract. A fraction of high-mass X-ray binaries are supergiant fast X-ray transients. These systems have on average low X-ray luminosities, but display short flares during which their X-ray luminosity rises by a few orders of magnitude. The leading model for the physics governing this X-ray behaviour suggests that the winds of the donor OB supergiants are magnetized. In agreement with this model, the first spectropolarimetric observations of the SFXT IGR J11215-5952 using the FORS 2 instrument at the Very Large Telescope indicate the presence of a kG longitudinal magnetic field. Based on these results, it seems possible that the key difference between supergiant fast X-ray transients and other high-mass X-ray binaries are the properties of the supergiant’s stellar wind and the physics of the wind’s interaction with the neutron star magnetosphere.

Constraining convection across the AGB with high-angular-resolution observations

2018 ◽  
Vol 14 (S343) ◽  
pp. 27-30
Author(s):  
Claudia Paladini ◽  
Fabien Baron ◽  
A. Jorissen ◽  
J.-B. Le Bouquin ◽  
B. Freytag ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Granule Size ◽  
Scaling Relations ◽  
High Angular Resolution ◽  
Large Telescope ◽  
Horizontal Scale ◽  
Very Large Telescope ◽  
Convective Pattern ◽  
Surface Convection ◽  
First Time

AbstractWe present very detailed images of the photosphere of an AGB star obtained with the PIONIER instrument, installed at the Very Large Telescope Interferometer (VLTI). The images show a well defined stellar disc populated by a few convective patterns. Thanks to the high precision of the observations we are able to derive the contrast and granulation horizontal scale of the convective pattern for the first time in a direct way. Such quantities are then compared with scaling relations between granule size, effective temperature, and surface gravity that are predicted by simulations of stellar surface convection.

scholarly journals The WFIRST Science Archive and Analysis Center

2016 ◽  
Vol 12 (S325) ◽  
pp. 373-378
Author(s):  
Sara R. Heap ◽  
Alexander S. Szalay ◽  
Keyword(s):  
Angular Resolution ◽  
Software Tools ◽  
Field Of View ◽  
Large Field ◽  
Wide Field ◽  
Data Volume ◽  
Analysis Center ◽  
Infrared Survey

AbstractThe Wide Field Infrared Survey Telescope (WFIRST) is a 2.4 m telescope with a large field of view ( ~ 0.3 deg2) and fine angular resolution (0.11”). WFIRST’s Wide Field Instrument (WFI) will obtain images in the Z, Y, J, H, F184, W149 (wide) filter bands, and grism spectra of the same large field of view. The data volume of the WFIRST Science Archive is expected to reach a few Petabytes. We describe plans to enable users to find the data of interest and, if needed, to analyze the datain situusing sophisticated software tools provided by the archive. As preparation, we are building a mini-archive that will help us to define realistic science requirements and to design the full WFIRST Science Archive.

scholarly journals Surface properties of icy transneptunian objects from the second ESO large program

2009 ◽  
Vol 5 (S263) ◽  
pp. 186-191
Author(s):  
Francesca E. DeMeo ◽  
Maria Antonietta Barucci ◽  
Alvaro Alvarez-Candal ◽  
Catherine de Bergh ◽  
Sonia Fornasier ◽  
...  
Keyword(s):  
Solar System ◽  
Surface Properties ◽  
New Technology ◽  
Outer Solar System ◽  
Large Telescope ◽  
Very Large Telescope ◽  
Large Program ◽  
Transneptunian Objects ◽  
Photometric Color

AbstractAn analysis is well underway for the data from the second Large Program (PI M. A. Barucci) dedicated to investigating the surface properties of Centaurs and Transneptunian objects through spectroscopic, photometric color, lightcurve, and polarimetric observations using the European Southern Observatory (ESO) Very Large Telescope (VLT) and New Technology Telescope (NTT). 45 objects were observed between 2006 and 2008, allowing a broad characterization of at least the largest and brightest objects among this population. In this report, we summarize all our findings, but focus on the analysis of the presence of ices such as methane, ethane, nitrogen, ammonia hydrate, methanol, and particularly H2O which is so abundant throughout the outer solar system.

scholarly journals TYC 8606-2025-1: a mild barium star surrounded by the ejecta of a very late thermal pulse

2019 ◽  
Vol 489 (4) ◽  
pp. 5136-5145 ◽  
Author(s):  
V V Gvaramadze ◽  
Yu V Pakhomov ◽  
A Y Kniazev ◽  
T A Ryabchikova ◽  
N Langer ◽  
...  
Keyword(s):  
Evolutionary Stage ◽  
Wide Field ◽  
Optical Counterpart ◽  
Large Telescope ◽  
Velocity Measurements ◽  
Thermal Pulse ◽  
Orbital Rotation ◽  
Spiral Shape ◽  
Process Elements ◽  
Infrared Survey

ABSTRACT We report the discovery of a spiral-like nebula with the Wide-field Infrared Survey Explorer and the results of optical spectroscopy of its associated star TYC 8606-2025-1 with the Southern African Large Telescope. We find that TYC 8606-2025-1 is a G8 III star of $\approx 3 \, \rm \, M_{\odot }$, showing a carbon depletion by a factor of 2 and a nitrogen enhancement by a factor of 3. We also derived an excess of s-process elements, most strongly for barium, which is a factor of 3 overabundant, indicating that TYC 8606-2025-1 is a mild barium star. We thereby add a new member to the small group of barium stars with circumstellar nebulae. Our radial velocity measurements indicate that TYC 8606-2025-1 has an unseen binary companion. The advanced evolutionary stage of TYC 8606-2025-1, together with the presence of a circumstellar nebula, implies an initial mass of the companion of also about $3 \, \rm \, M_{\odot }$. We conclude that the infrared nebula, due to its spiral shape, and because it has no optical counterpart, was ejected by the companion as a consequence of a very late thermal pulse, during about one orbital rotation.

scholarly journals Interferometry of massive stars: the next step

2014 ◽  
Vol 9 (S307) ◽  
pp. 480-489
Author(s):  
Ph. Stee ◽  
A. Meilland ◽  
O. L. Creevey
Keyword(s):  
Differential Rotation ◽  
Angular Resolution ◽  
Massive Stars ◽  
High Angular Resolution ◽  
Third Generation ◽  
Optical Interferometer ◽  
Large Telescope ◽  
Very Large Telescope ◽  
Beam Combiner ◽  
Radial Pulsations

AbstractWe present some new and interesting results on the complementarity between asteroseismology and interferometry, the detection of non-radial pulsations in massive stars and the possibility for evidencing differential rotation on the surface of Bn stars. We also discuss the curretn interferometric facilities, namely the Very Large Telescope Interferometer (VLTI)/AMBER, VLTI/MIDI, VLTI/PIONIER within the European Southern Observatory (ESO) context and the Center for High Angular Resolution Astronomy (CHARA) array with their current limitations. The forthcoming second-generation VLTI instruments GRAVITY and MATISSE are presented as well as the FRIEND prototype in the visible spectral domain and an update of the Navy Precision Optical Interferometer (NPOI). A conclusion is presented with a special emphasis on the foreseen difficulties for a third generation of interferometric instruments within the (budget limited) Extremely Large Telescope framework and the need for strong science cases to push a future visible beam combiner.

scholarly journals HAWK-I: the high-acuity wide-field K-band imager for the ESO Very Large Telescope

2008 ◽  
Vol 491 (3) ◽  
pp. 941-950 ◽  
Author(s):  
M. Kissler-Patig ◽  
J.-F. Pirard ◽  
M. Casali ◽  
A. Moorwood ◽  
N. Ageorges ◽  
...  
Keyword(s):  
Wide Field ◽  
Large Telescope ◽  
Very Large Telescope ◽  
High Acuity ◽  
K Band

scholarly journals Solar system science with the Wide-Field Infrared Survey Telescope

2018 ◽  
Vol 4 (03) ◽  
pp. 1 ◽  
Author(s):  
Bryan J. Holler ◽  
Stefanie N. Milam ◽  
James M. Bauer ◽  
Charles Alcock ◽  
Michele T. Bannister ◽  
...  
Keyword(s):  
Solar System ◽  
Wide Field ◽  
System Science ◽  
Infrared Survey

scholarly journals Unusual polarimetric properties for interstellar comet 2I/Borisov

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
S. Bagnulo ◽  
A. Cellino ◽  
L. Kolokolova ◽  
R. Nežič ◽  
T. Santana-Ros ◽  
...  
Keyword(s):  
Solar System ◽  
Physical Characteristics ◽  
Dust Particles ◽  
The Sun ◽  
Large Telescope ◽  
European Southern Observatory ◽  
Long Period ◽  
Very Large Telescope ◽  
Cometary Activity

AbstractSo far, only two interstellar objects have been observed within our Solar System. While the first one, 1I/‘Oumuamua, had asteroidal characteristics, the second one, 2I/Borisov, showed clear evidence of cometary activity. We performed polarimetric observations of comet 2I/Borisov using the European Southern Observatory Very Large Telescope to derive the physical characteristics of its coma dust particles. Here we show that the polarization of 2I/Borisov is higher than what is typically measured for Solar System comets. This feature distinguishes 2I/Borisov from dynamically evolved objects such as Jupiter-family and all short- and long-period comets in our Solar System. The only object with similar polarimetric properties as 2I/Borisov is comet C/1995 O1 (Hale-Bopp), an object that is believed to have approached the Sun only once before its apparition in 1997. Unlike Hale-Bopp and many other comets, though, comet 2I/Borisov shows a polarimetrically homogeneous coma, suggesting that it is an even more pristine object.

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