Metal Pollution of the Solar White Dwarf by Solar System Small Bodies

White dwarfs (WDs) often show metal lines in their spectra, indicating accretion of asteroidal material. Our Sun is to become a WD in several gigayears. Here, we examine how the solar WD accretes from the three major small body populations: the main belt asteroids (MBAs), Jovian Trojan asteroids (JTAs), and trans-Neptunian objects (TNOs). Owing to the solar mass loss during the giant branch, 40% of the JTAs are lost but the vast majority of MBAs and TNOs survive. During the WD phase, objects from all three populations are sporadically scattered onto the WD, implying ongoing accretion. For young cooling ages ≲100 Myr, accretion of MBAs predominates; our predicted accretion rate ∼106 g s−1 falls short of observations by two orders of magnitude. On gigayear timescales, thanks to the consumption of the TNOs that kicks in ≳100 Myr, the rate oscillates around 106–107 g s−1 until several gigayears and drops to ∼105 g s−1 at 10 Gyr. Our solar WD accretion rate from 1 Gyr and beyond agrees well with those of the extrasolar WDs. We show that for the solar WD, the accretion source region evolves in an inside-out pattern. Moreover, in a realistic small body population with individual sizes covering a wide range as WD pollutants, the accretion is dictated by the largest objects. As a consequence, the accretion rate is lower by an order of magnitude than that from a population of bodies of a uniform size and the same total mass and shows greater scatter.

Predicting the Solar System small bodies harvest of the BlackGEM Telescope Array

<p>*on behalf of the BlackGEM consortium</p> <p>BlackGEM is a Dutch-led wide-field optical telescope array dedicated to measure the optical emission from pairs of merging neutron stars and black holes. The array will start with three identical telescopes of 65 cm diameter, located at ESO La Silla, Chile. Each telescope is equipped with a 110 Mpix camera, consisting of a single 10.5k x 10.5k CCD, and covering 2.7 square degrees in one go, at 0.56 "/pix. The telescopes can work together as a single 3.6-meter telescope or look at different parts of the sky. The BlackGEM will perform four different science surveys and the BlackGEM Trigger Mode.</p> <p>The goal of our project is to estimate the potential of the BlackGEM telescope array for detecting various populations of the known Solar System small bodies, as well as for discovering the new ones. We create a software that simulates the BlackGEM surveys, determines the observability of the known Solar System small bodies, and determines the detectability of undiscovered objects with the BlackGEM array telescopes.</p>

Sample return of primitive matter from the outer Solar System

<p>The last thirty years of cosmochemistry and planetary science have shown that one major Solar System reservoir is vastly undersampled in the available suite of extra-terrestrial materials, namely small bodies that formed in the outer Solar System (>10AU). Because various dynamical evolutionary processes have modified their initial orbits (e.g., giant planet migration, resonances), these objects can be found today across the entire Solar System as P/D near-Earth and main-belt asteroids, Jupiter and Neptune Trojans, comets, Centaurs, and small (diameter <200km) trans-Neptunian objects. This reservoir is of tremendous interest, as it is recognized as the least processed since the dawn of the Solar System and thus the closest to the starting materials from which the Solar System formed. Some of the next major breakthroughs in planetary science will come from studying outer Solar System samples (volatiles and refractory constituents) in the laboratory. Yet, this can only be achieved by an L-class mission that<br />directly collects and returns to Earth materials from this reservoir. It is thus not surprising that two white papers advocating a sample return<br />mission of a primitive Solar System small body (ideally a comet) were submitted to ESA in response to its call for ideas for future L-class<br />missions in the 2035-2050 time frame. I will present an overview of the ideas listed in one of these two white papers and discuss how such a<br />mission would be complementary to current and future ground based observations of primitive Solar System small bodies.</p>

The IMPACTON Project: Pole and Shape of Eight Near-Earth Asteroids

The formation and evolution of Solar System small bodies, in particular those in near-Earth orbits, is a complex problem which solution strongly depends on a better knowledge of their physical properties. To contribute to the international efforts in this direction the IMPACTON project (www.on.br/IMPACTON) set up a dedicated facility denominated Observatório Astronômico do Sertão de Itaparica (OASI). Using the 1-m telescope several dozens of NEAs were observed between March 2012 and October 2014. Here we will present the results obtained for 8 objects. Relative magnitudes were used to obtain lightcurves and derive rotational periods. Applying the inversion method developed by Kaasalainen and Torppa (2001) and Kaasalainen et al. (2001), along with lightcurves from literature, allowed to refine the rotational period of these asteroids as well as to derive their pole direction and shape. The obtained results confirm a lack of poles toward the ecliptic and with a majority of retrograde rotators. A more representative sample, however, is needed in order to drive robust conclusions.