scholarly journals Astrid-2, an advanced microsatellite for auroral research

2001 ◽  
Vol 19 (6) ◽  
pp. 589-592 ◽  
Author(s):  
G. T. Marklund ◽  
L. G. Blomberg ◽  
S. Persson
Keyword(s):  
Quality Data ◽  
New Era ◽  
Scientific Mission ◽  
Electric And Magnetic Fields ◽  
Global Magnetic Field ◽  
Successful Launch ◽  
Low Mass ◽  
Instruments And Techniques ◽  
Scientific Results ◽  
Auroral Phenomena

Abstract. The successful launch of the Swedish microsatellite Astrid-2 in December 1998 began a new era of auroral research, with advanced microprobes of 30 kg or less used as research tools. Innovative technologies and low-mass solutions were used for the sensors and deployment systems to allow a fairly complete set of scientific instruments within the 10 kg allocated for the scientific payload. A newly developed wire boom deployment system proved to function excellently. During its seven month lifetime Astrid-2 collected more than 26 Gbytes of high-quality data of auroral electric and magnetic fields, and auroral particle and plasma characteristics from approximately 3000 orbits at an inclination of 83° and an altitude of about 1000 km. Scientific results cover a broad range of topics, from the physics of energization of auroral particles to how the magnetosphere responds to the energy input from the solar wind and global magnetic field modelling. The fulfilment of both the technological and the scientific mission objectives has opened entirely new possibilities to carry out low-budget multipoint measurements in near-Earth space.Key words. Ionosphere (auroral ionosphere; instruments and techniques) – Magnetospheric physics (auroral phenomena)

scholarly journals The MEDUSA electron and ion spectrometer and the PIA ultraviolet photometers on Astrid-2

2001 ◽  
Vol 19 (6) ◽  
pp. 593-600 ◽  
Author(s):  
O. Norberg ◽  
J. D. Winningham ◽  
H. Lauche ◽  
W. Keith ◽  
W. Puccio ◽  
...  
Keyword(s):  
Technological Development ◽  
Low Cost ◽  
Local Magnetic Field ◽  
High Temporal Resolution ◽  
Two Dimensional ◽  
Spin Plane ◽  
Low Mass ◽  
Instruments And Techniques ◽  
Auroral Emissions ◽  
Auroral Phenomena

Abstract. The miniature electron and ion spectrometer MEDUSA on Astrid-2 consists of two "top-hat"-type spherical electrostatic analyzers, sharing a common top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second) allow for very high temporal resolution measurements of a two-dimensional slice of the particle distribution function. The energy range covered, is in the case of electrons, 4 eV to 22 keV and, in the case of ions, 2 eV to 12 keV. MEDUSA is mounted with its aperture close to the spin plane of Astrid-2, which allows for good pitch-angle coverage when the local magnetic field is in the satellite spin plane. The PIA-1/2 spin-scanning ultraviolet photometers measure auroral emissions. Using the spacecraft spin and orbital motion, it is possible to create two-dimensional images from the data. Spin-scanning photometers, such as PIA, are low-cost, low mass alternatives to auroral imagers, but place constraints on the satellite attitude. Data from MEDUSA are used to study processes in the auroral region, in particular, electrodynamics of aurora and "black aurora". MEDUSA is also a technological development, paving the way for highly capable, miniaturized particle spectrometers.Key words. Ionosphere (instruments and techniques) – Magnetospheric physics (auroral phenomena; instruments and techniques)

scholarly journals An overview of the Planck mission

2010 ◽  
Vol 6 (S274) ◽  
pp. 268-273
Author(s):  
N. Mandolesi ◽  
C. Burigana ◽  
A. Gruppuso ◽  
P. Procopio ◽  
S. Ricciardi
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Analysis Pipeline ◽  
Sky Surveys ◽  
Flight Data ◽  
Compact Source ◽  
Effective Aperture ◽  
Successful Launch ◽  
Scientific Results ◽  
Data Analysis Pipeline

AbstractThis paper provides an overview of the ESA Planck mission and its scientific promises. Planck is equipped with a 1.5–m effective aperture telescope with two actively-cooled instruments observing the sky in nine frequency channels from 30 GHz to 857 GHz: the Low Frequency Instrument (LFI) operating at 20 K with pseudo-correlation radiometers, and the High Frequency Instrument (HFI) with bolometers operating at 100 mK. After the successful launch in May 2009, Planck has already mapped the sky twice (at the time of writing this review) with the expected behavior and it is planned to complete at least two further all-sky surveys. The first scientific results, consisting of an Early Release Compact Source Catalog (ERCSC) and in about twenty papers on instrument performance in flight, data analysis pipeline, and main astrophysical results, will be released on January 2011. The first publications of the main cosmological implications are expected in 2012.

Detection and Characterization Methods of Exoplanets

2020 ◽  
Author(s):  
Nuno C. Santos ◽  
Susana C.C. Barros ◽  
Olivier D.S. Demangeon ◽  
João P. Faria
Keyword(s):  
Stellar Disk ◽  
Observational Assessment ◽  
Characterization Methods ◽  
New Era ◽  
The Galaxy ◽  
Solar Type ◽  
Low Mass ◽  
Stellar Motion ◽  
New Generation ◽  
The Universe

Is the Solar System unique, or are planets ubiquitous in the universe? The answer to this long-standing question implies the understanding of planet formation, but perhaps more relevant, the observational assessment of the existence of other worlds and their frequency in the galaxy. The detection of planets orbiting other suns has always been a challenging task. Fortunately, technological progress together with significant development in data reduction and analysis processes allowed astronomers to finally succeed. The methods used so far are mostly based on indirect approaches, able to detect the influence of the planets on the stellar motion (dynamical methods) or the planet’s shadow as it crosses the stellar disk (transit method). For a growing number of favorable cases, direct imaging has also been successful. The combination of different methods also allowed probing planet interiors, composition, temperature, atmospheres, and orbital architecture. Overall, one can confidently state that planets are common around solar-type stars, low mass planets being the most frequent among them. Despite all the progress, the discovery and characterization of temperate Earth-like worlds, similar to the Earth in both mass and composition and thus potential islands of life in the universe, is still a challenging task. Their low amplitude signals are difficult to detect and are often submerged by the noise produced by different instrumentation sources and astrophysical processes. However, the dawn of a new generation of ground and space-based instruments and missions is promising a new era in this domain.

scholarly journals A Practical Approach to Artificial Intelligence in Plastic Surgery

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Akash Chandawarkar ◽  
Christian Chartier ◽  
Jonathan Kanevsky ◽  
Phaedra E Cress
Keyword(s):  
Artificial Intelligence ◽  
Data Collection ◽  
Plastic Surgery ◽  
Aesthetic Surgery ◽  
Practical Approach ◽  
Quality Data ◽  
Surgical Innovation ◽  
Mathematical Basis ◽  
New Era ◽  
Quantitative Studies

Abstract Understanding the intersection of technology and plastic surgery has been and will be essential to positioning plastic surgeons at the forefront of surgical innovation. This account of the current and future applications of artificial intelligence (AI) in reconstructive and aesthetic surgery introduces us to the subset of issues amenable to support from this technology. It equips plastic surgeons with the knowledge to navigate technical conversations with peers, trainees, patients, and technical partners for collaboration and to usher in a new era of technology in plastic surgery. From the mathematical basis of AI to its commercially viable applications, topics introduced herein constitute a framework for design and execution of quantitative studies that will better outcomes and benefit patients. Finally, adherence to the principles of quality data collection will leverage and amplify plastic surgeons’ creativity and undoubtedly drive the field forward.

scholarly journals Disorientation or the Impossibility of Knowledge Construction

Viatica ◽  
2017 ◽  
Author(s):  
Nathalie VUILLEMIN
Keyword(s):  
Knowledge Construction ◽  
Scientific Mission ◽  
Scientific Results

The article focuses on the epistemological and methodological questions typical of a scientific mission, looking particularly at the case of Joseph de Jussieu, a doctor-botanist who left for America in 1735, leaving only scattered letters and manuscripts from his trip. From his earliest investigations, Jussieu had difficulty in providing real scientific results on the botany of the country. As the years went by and his inner disorientation progressed, he stopped sending scholarly information in his letters, thus transforming his trip into a long stay.

scholarly journals Enhancing scientific dissemination in neuroscience via preprint peer-review: “Peer Community In Circuit Neuroscience”

2020 ◽  
Vol 2 ◽  
pp. e9
Author(s):  
Marion Mercier ◽  
Vincent Magloire ◽  
Mahesh Karnani
Keyword(s):  
Peer Review ◽  
New Technologies ◽  
Unmet Need ◽  
Open Science ◽  
Biomedical Science ◽  
Rigorous Evaluation ◽  
New Era ◽  
Negative Results ◽  
Scientific Results ◽  
Peer Community

The dissemination of scientific results and new technologies in biomedical science is rapidly evolving from an exclusive and fee-oriented publishing system towards more open, free and independent strategies for sharing knowledge. In this context, preprint servers such as bioRxiv answer a very real scientific need by enabling the rapid, free and easy dissemination of findings, regardless of whether these are novel, replicated, or even showcasing negative results. Currently, thousands of manuscripts are being shared via bioRxiv each month, and neuroscience is the largest and fastest growing subject category. However, commenting on bioRxiv is declining and no structured scientific validation such as peer-review is currently available. The Peer Community In (PCI) platform addresses this unmet need by facilitating the rigorous evaluation and validation of preprints, and PCI Circuit Neuroscience (PCI C Neuro) aims to develop and extend this tool for the neuroscience community. Here we discuss PCI C Neuro’s mission, how it works, and why it is an essential initiative in this new era of open science.

scholarly journals Microlensing Constraints on Low-Mass Companions

2003 ◽  
Vol 211 ◽  
pp. 305-308
Author(s):  
B. Scott Gaudi
Keyword(s):  
Detailed Analysis ◽  
Quality Data ◽  
Brute Force ◽  
Galactic Bulge ◽  
Force Analysis ◽  
Brown Dwarf ◽  
M Dwarfs ◽  
Survey Quality ◽  
Low Mass

Microlensing is sensitive to binary, brown dwarf (BD), and planetary companions to normal stars in the Galactic bulge with separations between about 1–10 AU. The accurate, densely-sampled photometry of microlensing events needed to detect planetary companions has been achieved by several follow-up collaborations. Detailed analysis of microlensing events toward the bulge demonstrates that less than 45% of M-dwarfs in the bulge have MJup companions between 1 and 5 AU. Detection of binary and BD companions using microlensing is considerably easier; however, the interpretation is hampered by their non-perturbative influence on the parent lightcurve. I demonstrate that ~ 25% of BD companions with separations 1 – 10AU should be detectable with survey-quality data (~ 1 day sampling and ~ 5% photometry). Survey data is more amenable to generic, brute-force analysis methods and less prone to selection biases. An analysis of the ~ 1500 microlensing events detected by OGLE-III in the next three years should test whether the BD desert exists at separations 1 – 10AU from M-dwarfs in the Galactic bulge.

scholarly journals Preliminary results from the MEMO multicomponent measurements of waves on-board INTERBALL 2

1998 ◽  
Vol 16 (9) ◽  
pp. 1117-1136 ◽  
Author(s):  
F. Lefeuvre ◽  
M. Parrot ◽  
J. L. Rauch ◽  
B. Poirier ◽  
A. Masson ◽  
...  
Keyword(s):  
Cutoff Frequency ◽  
Accurate Estimation ◽  
Magnetic Field Direction ◽  
Propagation Characteristics ◽  
High Resolution Data ◽  
Source Regions ◽  
Electromagnetic Emissions ◽  
Instruments And Techniques ◽  
Auroral Phenomena ◽  
Wave Normal

Abstract. The MEMO (MEsure Multicomposante des Ondes) experiment is a part of the INTERBALL 2 wave consortium. It is connected to a total of six electric and nine magnetic independent sensors. It provides waveforms associated with the measurement of two to five components in three frequency bands: ELF (5–1000 Hz), VLF (1–20 kHz), LF (20–250 kHz). Preliminary analyses of low and high resolution data are presented. The emphasis is put on the estimation of the propagation characteristics of the observed waves.VLF hiss emissions are shown to be mainly whistler mode emissions, but other modes are present. An accurate estimation of the local plasma frequency is proposed when the low L = 0 cutoff frequency is identified. AKR emissions observed just above source regions are studied. R-X and L-O modes are found: the first at the lowest frequencies and the second at the highest. Both propagate with wave normal directions weakly oblique or quasi-parallel to the Earth's magnetic field direction. Propagation characteristics are also determined for a (non-drifting) fine structure of AKR. There is no fundamental difference with structurless events. Nightside and dayside bursts of ELF electromagnetic emissions are presented. It is not clear whether the two emissions belong to the "lion roar" emissions or not.Key words. Magnetospheric physics (auroral phenomena; plasma waves and instabilities; instruments and techniques)

scholarly journals The New Era of Eclipsing Binary Research with Large Telescopes

2006 ◽  
Vol 2 (S240) ◽  
pp. 69-78
Author(s):  
Ignasi Ribas
Keyword(s):  
Eclipsing Binaries ◽  
Host Galaxies ◽  
Low Mass Stars ◽  
Eclipsing Binary ◽  
New Era ◽  
Direct Distance ◽  
Infrared Spectral ◽  
Low Mass ◽  
Stellar Properties ◽  
Large Telescopes

AbstractThe advent of larger telescopes and powerful instrumentation enables the exploration of new aspects of faint eclipsing binaries that are just now becoming accessible. An example of this are eclipsing binaries in Local Group galaxies such as the LMC, SMC, M31 and M33, whose study yields not only stellar properties of stars formed in different chemical environments (thus providing useful model tests) but also direct distance determinations to the host galaxies. In general this is also applicable to eclipsing binaries belonging to any stellar ensemble. Another example is the observation and study of eclipsing very-low mass stars, brown dwarfs and planets. Besides the need for large telescopes because of their faintness, these also benefit from improved observational capabilities in the infrared spectral windows. Here we discuss the prospects for eclipsing binary research using photometry and spectroscopy from large telescopes.

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