scholarly journals Search for L5 Earth Trojans with DECam

2020 ◽  
Vol 492 (4) ◽  
pp. 6105-6119
Author(s):  
Larissa Markwardt ◽  
D W Gerdes ◽  
R Malhotra ◽  
J C Becker ◽  
S J Hamilton ◽  
...  
Keyword(s):  
Solar System ◽  
Confidence Limit ◽  
System Support ◽  
Lagrange Points ◽  
Magnitude Distribution ◽  
Upper Limits

ABSTRACT Most of the major planets in the Solar system support populations of co-orbiting bodies, known as Trojans, at their L4 and L5 Lagrange points. In contrast, Earth has only one known co-orbiting companion. This paper presents the results from a search for Earth Trojans (ETs) using the DECam instrument on the Blanco Telescope at CTIO. This search found no additional Trojans in spite of greater coverage compared to previous surveys of the L5 point. Therefore, the main result of this work is to place the most stringent constraints to date on the population of ETs. These constraints depend on assumptions regarding the underlying population properties, especially the slope of the magnitude distribution (which in turn depends on the size and albedo distributions of the objects). For standard assumptions, we calculate upper limits to a 90 per cent confidence limit on the L5 population of NET < 1 for magnitude H < 15.5, NET = 60–85 for H < 19.7, and NET = 97 for H = 20.4. This latter magnitude limit corresponds to Trojans ∼300 m in size for albedo 0.15. At H = 19.7, these upper limits are consistent with previous L4 ET constraints and significantly improve L5 constraints.

scholarly journals CAPTURE OF DARK MATTER BY THE SOLAR SYSTEM

2009 ◽  
Vol 18 (12) ◽  
pp. 1903-1912 ◽  
Author(s):  
I. B. KHRIPLOVICH ◽  
D. L. SHEPELYANSKY
Keyword(s):  
Dark Matter ◽  
Solar System ◽  
Dark Matter Particle ◽  
Matter Density ◽  
Upper And Lower Bounds ◽  
Analytical Estimate ◽  
Upper Limits ◽  
Galactic Dark Matter ◽  
Three Body ◽  
Optimistic Value

We study the capture of galactic dark matter by the solar system. The effect is due to the gravitational three-body interaction between the sun, one of the planets, and a dark matter particle. The analytical estimate for the capture cross-section is derived and the upper and lower bounds for the total mass of the captured dark matter particles are found. The estimates for their density are less reliable. The most optimistic of them gives an enhancement of dark matter density by about three orders of magnitudes compared to its value in our galaxy. However, even this optimistic value remains below the best present observational upper limits by about two orders of magnitude.

scholarly journals Upper limits on the water vapour content of the β Pictoris debris disk

2019 ◽  
Vol 628 ◽  
pp. A127 ◽  
Author(s):  
M. Cavallius ◽  
G. Cataldi ◽  
A. Brandeker ◽  
G. Olofsson ◽  
B. Larsson ◽  
...  
Keyword(s):  
Solar System ◽  
Far Infrared ◽  
Kinetic Temperature ◽  
Line Flux ◽  
Water Vapour Content ◽  
Water Ice ◽  
Upper Limit ◽  
Upper Limits ◽  
Debris Disk ◽  
Lower Limits

Context. The debris disk surrounding β Pictoris has been observed with ALMA to contain a belt of CO gas with a distinct peak at ~85 au. This CO clump is thought to be the result of a region of enhanced density of solids that collide and release CO through vaporisation. The parent bodies are thought to be comparable to solar system comets, in which CO is trapped inside a water ice matrix. Aims. Since H2O should be released along with CO, we aim to put an upper limit on the H2O gas mass in the disk of β Pictoris. Methods. We used archival data from the Heterodyne Instrument for the Far-Infrared (HIFI) aboard the Herschel Space Observatory to study the ortho-H2O 110–101 emission line. The line is undetected. Using a python implementation of the radiative transfer code RADEX, we converted upper limits on the line flux to H2O gas masses. The resulting lower limits on the CO/H2O mass ratio are compared to the composition of solar system comets. Results. Depending on the assumed gas spatial distribution, we find a 95% upper limit on the ortho-H2O line flux of 7.5 × 10−20 W m−2 or 1.2 × 10−19 W m−2. These translate into an upper limit on the H2O mass of 7.4 × 1016–1.1 × 1018 kg depending on both the electron density and gas kinetic temperature. The range of derived gas-phase CO/H2O ratios is marginally consistent with low-ratio solar system comets.

scholarly journals Survey of planetesimal belts with ALMA: gas detected around the Sun-like star HD 129590

2020 ◽  
Vol 497 (3) ◽  
pp. 2811-2830 ◽  
Author(s):  
Quentin Kral ◽  
Luca Matrà ◽  
Grant M Kennedy ◽  
Sebastian Marino ◽  
Mark C Wyatt
Keyword(s):  
Solar System ◽  
Main Sequence ◽  
Signal To Noise Ratio ◽  
Gas Detection ◽  
Continuum Emission ◽  
Geometrical Properties ◽  
Upper Limits ◽  
Co Detection ◽  
Outgassing Rate ◽  
First Time

ABSTRACT Gas detection around main-sequence stars is becoming more common with around 20 systems showing the presence of CO. However, more detections are needed, especially around later spectral type stars to better understand the origin of this gas and refine our models. To do so, we carried out a survey of 10 stars with predicted high likelihoods of secondary CO detection using ALMA in band 6. We looked for continuum emission of mm-dust as well as gas emission (CO and CN transitions). The continuum emission was detected in 9/10 systems for which we derived the discs’ dust masses and geometrical properties, providing the first mm-wave detection of the disc around HD 106906, the first mm-wave radius for HD 114082, 117214, HD 15745, HD 191089, and the first radius at all for HD 121191. A crucial finding of our paper is that we detect CO for the first time around the young 10–16 Myr old G1V star HD 129590, similar to our early Sun. The gas seems colocated with its planetesimal belt and its total mass is likely in the range of (2–10) × 10−5 M⊕. This first gas detection around a G-type main-sequence star raises questions as to whether gas may have been released in the Solar system as well in its youth, which could potentially have affected planet formation. We also detected CO gas around HD 121191 at a higher signal-to-noise ratio than previously and find that the CO lies much closer-in than the planetesimals in the system, which could be evidence for the previously suspected CO viscous spreading owing to shielding preventing its photodissociation. Finally, we make estimates for the CO content in planetesimals and the HCN/CO outgassing rate (from CN upper limits), which we find are below the level seen in Solar system comets in some systems.

scholarly journals The Stability of the Planetary Triangular Lagrange Points

1990 ◽  
Vol 123 ◽  
pp. 533-536
Author(s):  
Seppo Mikkola ◽  
K.A. Innanen
Keyword(s):  
Solar System ◽  
Progress Report ◽  
Scientific Applications ◽  
Medium Term ◽  
Lagrange Points ◽  
The Earth ◽  
Self Consistent ◽  
The Stability

AbstractNumerical, self-consistent, n-body integrations of the solar system show significant indications of medium-term (i.e. several million-year) stability for the various planet-Sun L4,L5 configurations. A progress report of our computations, emphasizing the inner solar system, will be given. There exist interesting possibilities for these locations (including the Earth) as the sites for longer term scientific applications, both pure and applied.

scholarly journals IS RADIATION OF QUANTIZED BLACK HOLES OBSERVABLE?

2007 ◽  
Vol 16 (07) ◽  
pp. 1243-1248 ◽  
Author(s):  
I. B. KHRIPLOVICH ◽  
N. PRODUIT
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Solar System ◽  
Evaporation Rate ◽  
Radiation Spectrum ◽  
Matter Density ◽  
Primordial Black Holes ◽  
Dark Matter Density ◽  
Upper Limit ◽  
Upper Limits

If primordial black holes (PBH) saturate the present upper limit on the dark matter density in our Solar system and if their radiation spectrum is discrete, the sensitivity of modern detectors is close to that necessary for detecting this radiation. This conclusion is not in conflict with the upper limits on the PBH evaporation rate.

scholarly journals Existence of Asteroids in the Inner Solar System

2004 ◽  
Vol 202 ◽  
pp. 238-240
Author(s):  
S. A. Tabachnik ◽  
N. W. Evans
Keyword(s):  
Solar System ◽  
Terrestrial Planets ◽  
Secular Resonance ◽  
Lagrange Points ◽  
The Earth ◽  
Numerical Integrations ◽  
Test Particles ◽  
Horseshoe Orbits

Ensembles of in-plane and inclined orbits in the vicinity of the Lagrange points of the terrestrial planets are integrated for up to 100 million years. Mercurian Trojans probably do not exist, although there is evidence for long-lived, corotating horseshoe orbits with small inclinations. Both Venus and the Earth are much more promising, as they possess rich families of stable tadpole and horseshoe orbits. Our survey of in-plane test particles near the Martian Lagrange points shows no survivors after 60 million years. Low inclination test particles do not persist, as their inclinations are quickly increased until the effects of a secular resonance with Jupiter cause de-stabilisation. Numerical integrations of inclined test particles for timespans of 25 million years show stable zones for inclinations between 14° and 40°. Both Martian Trojans 5261 Eureka and 1998 VF31 lie deep within the stable zones, which suggests they may be of primordial origin.

The NASA Lucy Mission: Surveying the Diversity of Trojan Asteroids

2020 ◽  
Author(s):  
Simone Marchi ◽  
Hal Levison ◽  
Cathy Olkin ◽  
Keith Noll
Keyword(s):  
Solar System ◽  
Infrared Imaging ◽  
Surface Composition ◽  
Equal Mass ◽  
Rotational Axis ◽  
Trojan Asteroids ◽  
Imaging Spectrometer ◽  
Axis Orientation ◽  
Lagrange Points ◽  
Wide Range

<p class="western" align="justify"><span>The Lucy Mission is a NASA Discovery class mission to send a highly capable and robust spacecraft to investigate </span><span>seven</span><span> Jupiter Trojan asteroids; a class of stable, primitive bodies near both the L4 and L5 Lagrange points with Jupiter. It is believed that Jupiter Trojan asteroids are leftover planetesimals from the outer planetary system that have been preserved since early in Solar System history, and represent the last of all of the stable populations of the Solar System to be visited by spacecraft. </span></p> <p class="western" align="justify"><span> Lucy is slated to launch in October 2021, reach its first Trojan asteroid in 2027, and have its final encounter in 2033. During its lifetime, Lucy will perform five Trojan encounters closely studying at least seven objects (one encounter is of a nearly equal mass binary and another is an asteroid with a known satellite). The science goals include determining the surface composition, assessing the geology, determining the bulk properties and searching for satellites around all of Lucy’s targets. The payload suite consists of a color camera and infrared imaging spectrometer, a high resolution panchromatic imager, and a thermal infrared spectrometer. Additionally, two spacecraft subsystems will also contribute to the science investigations: the terminal tracking cameras and the telecommunication subsystem to measure the mass of the Trojan asteroids.</span></p> <p class="western" align="justify"><span> Lucy’s Trojan targets include one C-type (Eurybates, 64 km in diameter), three P-types (Menoetius, Patroclus, and Polymele; 10</span><span>5</span><span>, 11</span><span>4</span><span>, 21 km in diameter, respectively), and two D-types (Leucus and Orus; </span><span>41</span><span> and 5</span><span>2</span><span> km in diameter, respectively), thereby covering a wide range of spectral types and sizes. Lucy will be the first spacecraft to observe the largest remnant of a catastrophic collision up close (Eurybates), and the first to visit a near-equal mass binary (Patroclus and Menoetius). In addition, on its way to L4, Lucy will fly by DonaldJohanson in 2025, a 4 km in diameter </span><span>Main Belt </span><span>asteroid named in honor of the discoverer of the Lucy fossil. In this talk, recent results from an international observational campaign of some of the Lucy’s targets will be presented, including the detection of a small satellite (1-2 km) orbiting Eurybates, and a detailed characterization of Leucus’s shape and rotational axis orientation.</span></p>

scholarly journals DENSITY OF DARK MATTER IN THE SOLAR SYSTEM AND PERIHELION PRECESSION OF PLANETS

2007 ◽  
Vol 16 (09) ◽  
pp. 1475-1478 ◽  
Author(s):  
I. B. KHRIPLOVICH
Keyword(s):  
Dark Matter ◽  
Solar System ◽  
Perihelion Precession ◽  
Upper Limits ◽  
Direct Model ◽  
Model Independent ◽  
Independent Relation

Direct model-independent relation between the secular perihelion precession of a planet and the density of dark matter ρ dm at its orbit is indicated, and used to deduce upper limits on local values of ρ dm .

scholarly journals UPPER LIMITS ON DENSITY OF DARK MATTER IN SOLAR SYSTEM

2006 ◽  
Vol 15 (04) ◽  
pp. 615-618 ◽  
Author(s):  
I. B. KHRIPLOVICH ◽  
E. V. PITJEVA
Keyword(s):  
Dark Matter ◽  
Solar System ◽  
Observational Data ◽  
Perihelion Precession ◽  
Upper Limits

The analysis of the observational data for the secular perihelion precession of Mercury, Earth, and Mars, based on the EPM2004 ephemerides, results in new upper limits on density of dark matter in the solar system.

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