The solar system data in the forthcoming Data Release 3 by the Gaia mission of ESA: a preview

2021 ◽  
Author(s):  
Paolo Tanga

<p>The Data Release 3 by the Gaia mission (ESA) will not only multiply by a large factor the volume of observations, but will also add more quality and complexity. With respect to DR2, that appeared in 2018. The number of asteroids with astrometry and photometry will be multiplied by a factor >10, and data will span a longer time interval. Also, for the first time a set of reflectance spectra for several thousand asteroids will be released. Some planetary satellites and candidate new asteroids will also be included. The improvement in volume, accuracy and variety of data will add new dimensions to the contribution of Gaia to asteroid science as this will probably be the most extensive and self consistent set of visible spectra available up to know. </p> <p>In this talk, we will mainly focus on the general properties of the asteroid data in DR3 (statistics on the sample) and on the improvement in astrometry with respect to DR2. Based on the results obtained from the exploitation of DR2, we will review the expected impact of DR3 in terms of improved orbits, Yarkovsky determination, prediction of asteroid occultations. The properties of asteroid spectra in DR3 will be presented in another contribution to this meeting by M. Delbo'. </p>

Author(s):  
Marc Sanchez Net ◽  
Etienne Pellegrini ◽  
Wilson Parker ◽  
Joshua Vander Hook
Keyword(s):  

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 868
Author(s):  
Khrystyna Prysyazhnyk ◽  
Iryna Bazylevych ◽  
Ludmila Mitkova ◽  
Iryna Ivanochko

The homogeneous branching process with migration and continuous time is considered. We investigated the distribution of the period-life τ, i.e., the length of the time interval between the moment when the process is initiated by a positive number of particles and the moment when there are no individuals in the population for the first time. The probability generating function of the random process, which describes the behavior of the process within the period-life, was obtained. The boundary theorem for the period-life of the subcritical or critical branching process with migration was found.


Author(s):  
Scott M Croom ◽  
Matt S Owers ◽  
Nicholas Scott ◽  
Henry Poetrodjojo ◽  
Brent Groves ◽  
...  

Abstract We have entered a new era where integral-field spectroscopic surveys of galaxies are sufficiently large to adequately sample large-scale structure over a cosmologically significant volume. This was the primary design goal of the SAMI Galaxy Survey. Here, in Data Release 3 (DR3), we release data for the full sample of 3068 unique galaxies observed. This includes the SAMI cluster sample of 888 unique galaxies for the first time. For each galaxy, there are two primary spectral cubes covering the blue (370–570 nm) and red (630–740 nm) optical wavelength ranges at spectral resolving power of R = 1808 and 4304 respectively. For each primary cube, we also provide three spatially binned spectral cubes and a set of standardized aperture spectra. For each galaxy, we include complete 2D maps from parameterized fitting to the emission-line and absorption-line spectral data. These maps provide information on the gas ionization and kinematics, stellar kinematics and populations, and more. All data are available online through Australian Astronomical Optics (AAO) Data Central.


2010 ◽  
Vol 9 (4) ◽  
pp. 273-291 ◽  
Author(s):  
J. Horner ◽  
B.W. Jones

AbstractWithin the next few years, the first Earth-mass planets will be discovered around other stars. Some of those worlds will certainly lie within the classical ‘habitable zone’ of their parent stars, and we will quickly move from knowing of no exoEarths to knowing many. For the first time, we will be in a position to carry out a detailed search for the first evidence of life beyond our Solar System. However, such observations will be hugely taxing and time consuming to perform, and it is almost certain that far more potentially habitable worlds will be known than it is possible to study. It is therefore important to catalogue and consider the various effects that make a promising planet more or less suitable for the development of life. In this work, we review the various planetary, dynamical and stellar influences that could influence the habitability of exoEarths. The various influences must be taken in concert when we attempt to decide where to focus our first detailed search for life. While there is no guarantee that any given planet will be inhabited, it is vitally important to ensure that we focus our time and effort on those planets most likely to yield a positive result.


2021 ◽  
Author(s):  
Marco Delbo ◽  
Laurent Galluccio ◽  
Francesca De Angeli ◽  
Paolo Tanga ◽  
Alberto Cellino ◽  
...  

<div class="">Asteroids reflectance spectra in the visible light will be one of the novel products of the Gaia Data Release 3 (DR3). These spectra are produced from Gaia observations obtained by means of the blue and red photometers — the so-called BP and RP, respectively. We will review the strategy adopted to produce asteroid reflectance spectra from BP-RP data, focusing on the choice of spectro-photometric calibrations computed taking into account solar system object astrometry and suitable lists of solar-analog stars.</div> <div class=""> </div> <div class="">Our preliminary investigation shows that we will be able to obtain reflectance spectra for asteroids as small as some km in the main belt, by exploiting the fact that each object has been observed multiple times by Gaia. We will show the capability of Gaia to probe the detailed compositional gradient of the main belt down to small sizes and to study correlations between spectral classes and other asteroid physical parameters, such as albedo and size.</div> <div class=""> </div> <div class="">Concerning the brightest asteroids, we expect to have substantial signal at wavelengths shorter than 450 nm, allowing Gaia to examine this region of the spectrum that has been poorly investigated by ground-based asteroid spectroscopic surveys. This region is characterised by the presence of a reflectance downturn that is diagnostic for the composition of classes of primitive asteroids, for instance those including the parent bodies of carbonaceous chondrites. These asteroids may have played an important role for the delivery of prebiotic compounds to Earth during the early phases of solar system' s history and, as such, are at the center of attention of the planetary science community. </div>


Science ◽  
2018 ◽  
Vol 360 (6395) ◽  
pp. 1342-1346 ◽  
Author(s):  
Thomas E. Collett ◽  
Lindsay J. Oldham ◽  
Russell J. Smith ◽  
Matthew W. Auger ◽  
Kyle B. Westfall ◽  
...  

Einstein’s theory of gravity, General Relativity, has been precisely tested on Solar System scales, but the long-range nature of gravity is still poorly constrained. The nearby strong gravitational lens ESO 325-G004 provides a laboratory to probe the weak-field regime of gravity and measure the spatial curvature generated per unit mass, γ. By reconstructing the observed light profile of the lensed arcs and the observed spatially resolved stellar kinematics with a single self-consistent model, we conclude that γ = 0.97 ± 0.09 at 68% confidence. Our result is consistent with the prediction of 1 from General Relativity and provides a strong extragalactic constraint on the weak-field metric of gravity.


1985 ◽  
Vol 112 ◽  
pp. 157-164
Author(s):  
J. Mayo Greenberg ◽  
Peter Weber

For the first time a laboratory simulation of the effect of the interstellar environment has been used to provide quantitative estimates of bacterial spore survival in the space between the stars. In the diffuse regions between clouds ten percent survival is limited to at most hundreds of years although one in ten thousand may survive for several thousand years. Within common dense clouds the ten percent life expectancy is extended to tens of millions of years because of the severely reduced ultraviolet within these clouds as well as because of the accretion of ultraviolet absorbing mantles on the spores. The random motion of molecular clouds is shown to provide a possible vehicle for transport of spores from one solar system to another. The most hazardous times in such a journey are at the start and finish and, although the requirements for survival during these periods are quantified here, the possibility or probability of their being satisfied remains pure conjecture.


1987 ◽  
Vol 120 ◽  
pp. 443-445
Author(s):  
Valerio Pirronello

It is described a method for evaluating the low energy cosmic ray flux outside the heliosphere. It is based on the chemical modifications induced in cometary nuclei by impinging ions and on the release of synthesized chemical species by comets entering for the first time into the inner solar system.


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