scholarly journals 21. Light of the Night Sky / Lumière du Ciel Nocturne

1997 ◽  
Vol 23 (1) ◽  
pp. 231-236
Author(s):  
Christoph Leinert
Keyword(s):  
Interstellar Dust ◽  
Thermal Emission ◽  
Scattered Light ◽  
Diffuse Radiation ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Zodiacal Light ◽  
Interplanetary Dust Particles ◽  
Extragalactic Background Light ◽  
Night Sky

The light of the night sky is a difficult to disentangle mixture of tropospherically scattered light, airglow, zodiacal light (including the thermal emission by interplanetary dust particles), unresolved stellar light, diffuse scattering and emission by interstellar dust and gas, and finally an extragalactic component. It has the reputation of being a very traditional field of astronomy, which certainly is true if we look at the long history of the subject. The recent renewed interest in this topic, which continued during this triennium, appears mainly to come from three sources: - first from the impressive results of the IRAS and COBE infrared satellites. They brought to general consciousness the fact that the infrared sky is characterised by strong emission from interplanetary and interstellar dust, and made clear that this emission may interfere with the study of faint interesting sources. - then from the development of sensitive detectors and arrays for essentially all of the wavelength range to be covered in this report, from the Lyman limit to ≈ 300 μm. Now the difficult measurements of the ultraviolet diffuse radiation and of the extragalactic background light in the infrared cosmological windows around 3 μm and 200 μm have become feasible and state of the art projects. - finally, the threat to astronomical observations arising from man-made development and lighting has become important enough to further studies of uncontaminated and contaminated night sky brightnesses. This report will refer mainly to those areas and is meant to highlight noteworthy developments. It was prepared with the help of Drs. Bowyer and Mattila.

scholarly journals Dust Measurements in the Outer Solar System

1994 ◽  
Vol 160 ◽  
pp. 367-380
Author(s):  
Eberhard Grün
Keyword(s):  
Solar System ◽  
Interstellar Dust ◽  
Thermal Emission ◽  
Scattered Light ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Spatial Density ◽  
Outer Solar System ◽  
The Sun

In-situ measurements of micrometeoroids provide information on the spatial distribution of interplanetary dust and its dynamical properties. Pioneers 10 and 11, Galileo and Ulysses spaceprobes took measurements of interplanetary dust from 0.7 to 18 AU distance from the sun. Distinctly different populations of dust particles exist in the inner and outer solar system. In the inner solar system, out to about 3 AU, zodiacal dust particles are recognized by their scattered light, their thermal emission and by in-situ detection from spaceprobes. These particles orbit the sun on low inclination (i ≤ 30°) and moderate eccentricity (e ≤ 0.6) orbits. Their spatial density falls off with approximately the inverse of the solar distance. Dust particles on high inclination or even retrograde trajectories dominate the dust population outside about 3 AU. The dust detector on board the Ulysses spaceprobe identified interstellar dust sweeping through the outer solar system on hyperbolic trajectories. Within about 2 AU from Jupiter Ulysses discovered periodic streams of dust particles originating from within the jovian system.

scholarly journals The Contribution of Kuiper Belt Dust Grains to the Inner Solar System

1996 ◽  
Vol 150 ◽  
pp. 163-166
Author(s):  
Jer-Chyi Liou ◽  
Herbert A. Zook ◽  
Stanley F. Dermott
Keyword(s):  
Solar System ◽  
Interstellar Dust ◽  
Numerical Study ◽  
Kuiper Belt ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Dust Grains ◽  
Zodiacal Light ◽  
Interplanetary Dust Particles ◽  
The Earth

AbstractThe recent discovery of the so-called Kuiper belt objects has prompted the idea that these objects produce dust grains that may contribute significantly to the interplanetary dust population at 1 AU. We have completed a numerical study of the orbital evolution of dust grains, of diameters 1 to 9 μm, that originate in the region of the Kuiper belt. Our results show that about 80% of the grains are ejected from the Solar System by the giant planets while the remaining 20% of the grains evolve all the way to the Sun. Surprisingly, these dust grains have small orbital eccentricities and inclinations when they cross the orbit of the Earth. This makes them behave more like asteroidal than cometary-type dust particles. This also enhances their chances to be captured by the Earth and makes them a possible source of the collected interplanetary dust particles (IDPs); in particular, they represent a possible source that brings primitive/organic materials from the outer Solar System to the Earth.When collisions with interstellar dust grains are considered, however, Kuiper belt dust grains larger than about 9 μm appear likely to be collisionally shattered before they can evolve to the inner part of the Solar System. Therefore, Kuiper belt dust grains may not, as they are expected to be small, contribute significantly to the zodiacal light.

scholarly journals COMMISSION 21: LIGHT OF THE NIGHT SKY

2008 ◽  
Vol 4 (T27A) ◽  
pp. 171-173
Author(s):  
Adolf N. Witt ◽  
Jayant Murthy ◽  
Bo Å. S. Gustafson ◽  
W. Jack Baggaley ◽  
Eli Dwek ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Thermal Emission ◽  
Interplanetary Dust ◽  
Zodiacal Light ◽  
Microwave Background ◽  
Interstellar Gas ◽  
Milky Way Galaxy ◽  
Thermal Emissions ◽  
Night Sky ◽  
Night Sky Brightness

Commission 21 consists of IAU members and consultants with expertise and interest in the study of the light of the night sky and its various diffuse components, at all accessible electromagnetic frequencies. In cosmic distance scales, the subjects of Commission 21 range from airglow and tropospheric scattering in Earth's atmosphere, through zodiacal light in the solar system, including thermal emission from interplanetary dust, integrated starlight in the Milky Way galaxy, diffuse galactic light due to dust scattering in the galactic diffuse interstellar medium, thermal emissions from interstellar dust and free free emission from ionized interstellar gas, to various diffuse extragalactic background sources, including the cosmologically important cosmic microwave background (CMB). Observations of the diffuse night sky brightness at any frequency typically include signals from several of these sources, and it has been the historic mandate of Commission 21 to foster the necessary collaboration of experts from the different astronomical sub-disciplines involved.

scholarly journals Analogues of interplanetary dust particles to interpret the zodiacal light polarization

2020 ◽  
Vol 183 ◽  
pp. 104527 ◽  
Author(s):  
E. Hadamcik ◽  
J. Lasue ◽  
A.C. Levasseur-Regourd ◽  
J.-B. Renard
Keyword(s):  
Interplanetary Dust ◽  
Light Polarization ◽  
Dust Particles ◽  
Zodiacal Light ◽  
Interplanetary Dust Particles

21. Light of the Night Sky (Lumiere Du Ciel Nocturne)

1988 ◽  
Vol 20 (1) ◽  
pp. 211-218
Author(s):  
K. Mattila ◽  
A. C. Levasseur-Regourd ◽  
R. Dumont ◽  
Yu. I. Galperin ◽  
R. H. Giese ◽  
...  
Keyword(s):  
Background Radiation ◽  
Scattered Light ◽  
Point Of View ◽  
Zodiacal Light ◽  
Extragalactic Background Light ◽  
Infrared Wavelength ◽  
Background Radiations ◽  
Infrared Background ◽  
Night Sky ◽  
Photometric Measurements

The different components of the light of the night sky have their origin in different formations of matter in the universe - encompassing a huge scale of distances ranging from a few kilometers in the earth’s atmosphere to the most distant known galaxies and beyond. Correspondingly, the borderlines to other Commissions are not very well defined and thus material relevant to Commission 21 can also be found in the reports of other Commissions on the following topics: zodiacal light and zodiacal IR emission (Comm. 22, 44), integrated starlight (33, 25), diffuse galactic light (34), extragalactic background light (47), airglow and atmospheric scattered light (50), and space-borne observations of the LONS (44). From the Commission 21 point of view the connecting link between these various fields is the special techniques utilized in the surface photometric measurements and reductions of background radiations which extend over the entire sky. One crucial problem is the separation of the LONS into its several components. The approach for solving this task is to utilize the different spatial distributions and different broad and narrow band spectral properties of each of the LONS component. Thus the successful measurement and separation of one of the LONS components requires a knowledge of the properties of all the other components. This situation has become apparent in recent years as the infrared background radiation database, provided by the Infrared Astronomical Satellite (IRAS), has been analyzed: both the zodiacal and galactic dust emissions have to be analyzed hand in hand, and both these components must be very accurately mastered before any conclusions are possible on the extragalactic component. It is also obvious that very similar problems are encountered in the ultraviolet and infrared wavelength regions as in the more traditional optical domain. Thus the techniques developed in one of these wavelength domains are directly applicable in the others.

ERE from Graphene Oxide in the ISM. A possible link to IOM?

2020 ◽  
Author(s):  
Peter Sarre
Keyword(s):  
Graphene Oxide ◽  
Organic Material ◽  
Interstellar Dust ◽  
Emission Spectra ◽  
Optical Emission ◽  
Interplanetary Dust ◽  
Infrared Emission ◽  
Dust Particles ◽  
Interplanetary Dust Particles ◽  
Infrared Space Observatory

<p>Dust particles play a major role in the formation, evolution and chemistry of interstellar clouds, stars, and planetary systems. Commonly identified forms include amorphous and crystalline carbon-rich particles and silicates. Also present in many astrophysical environments are polycyclic aromatic hydrocarbons (PAHs), detected through their infrared emission, and which are essentially small flakes of graphene. Astronomical observations over the past four decades have revealed a widespread unassigned ‘extended red emission’ (ERE) feature which is attributed to luminescence of dust grains. A luminescence feature with similar characteristics to ERE has been found in organic material in interplanetary dust particles and carbonaceous chondrites.  </p> <p>There is a strong similarity between laboratory optical emission spectra of graphene oxide (GO) and ERE, leading to this proposal that emission from GO nanoparticles is the origin of ERE and that heteroatom-containing PAH structures are a significant component of interstellar dust. The proposal is supported by infrared emission features detected by the <em>Infrared Space Observatory (ISO)</em> and the <em>Spitzer Space Telescope</em>.  </p> <p>Insoluble Organic Material (IOM) has a chemical structure with some similarities to graphene oxide.  It is suggested this may contribute to the discussion as to whether IOM has an origin in the interstellar medium or the solar nebula, or some combination.</p>

scholarly journals Multiple generations of grain aggregation in different environments preceded solar system body formation

2018 ◽  
Vol 115 (26) ◽  
pp. 6608-6613 ◽  
Author(s):  
Hope A. Ishii ◽  
John P. Bradley ◽  
Hans A. Bechtel ◽  
Donald E. Brownlee ◽  
Karen C. Bustillo ◽  
...  
Keyword(s):  
Solar System ◽  
Organic Carbon ◽  
Molecular Cloud ◽  
Interstellar Dust ◽  
Solar Nebula ◽  
Carbon Matrix ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Interplanetary Dust Particles ◽  
System Body

The solar system formed from interstellar dust and gas in a molecular cloud. Astronomical observations show that typical interstellar dust consists of amorphous (a-) silicate and organic carbon. Bona fide physical samples for laboratory studies would yield unprecedented insight about solar system formation, but they were largely destroyed. The most likely repositories of surviving presolar dust are the least altered extraterrestrial materials, interplanetary dust particles (IDPs) with probable cometary origins. Cometary IDPs contain abundant submicrona-silicate grains called GEMS (glass with embedded metal and sulfides), believed to be carbon-free. Some have detectable isotopically anomalousa-silicate components from other stars, proving they are preserved dust inherited from the interstellar medium. However, it is debated whether the majority of GEMS predate the solar system or formed in the solar nebula by condensation of high-temperature (>1,300 K) gas. Here, we map IDP compositions with single nanometer-scale resolution and find that GEMS contain organic carbon. Mapping reveals two generations of grain aggregation, the key process in growth from dust grains to planetesimals, mediated by carbon. GEMS grains, some witha-silicate subgrains mantled by organic carbon, comprise the earliest generation of aggregates. These aggregates (and other grains) are encapsulated in lower-density organic carbon matrix, indicating a second generation of aggregation. Since this organic carbon thermally decomposes above ∼450 K, GEMS cannot have accreted in the hot solar nebula, and formed, instead, in the cold presolar molecular cloud and/or outer protoplanetary disk. We suggest that GEMS are consistent with surviving interstellar dust, condensed in situ, and cycled through multiple molecular clouds.

scholarly journals The Infrared Zodiacal Light

1991 ◽  
Vol 126 ◽  
pp. 171-178
Author(s):  
Martha S. Hanner
Keyword(s):  
Optical Properties ◽  
Solar Eclipse ◽  
Heliocentric Distance ◽  
Thermal Emission ◽  
Diffuse Radiation ◽  
Interplanetary Dust ◽  
Zodiacal Light

AbstractThermal emission from interplanetary dust is the main source of diffuse radiation atλ5-50 μm. Analysis of infrared sky maps from IRAS and ZIP lead to the result that the average optical properties of the dust change with heliocentric distance. The present uncertainties in calibration should be resolved by COBE. Existence of a dust sublimation zone at 4 solar radii awaits confirmation at the next solar eclipse.

scholarly journals Dust in Dense Clouds

1989 ◽  
Vol 135 ◽  
pp. 239-262 ◽  
Author(s):  
A. G. G. M. Tielens
Keyword(s):  
Grain Size ◽  
Molecular Clouds ◽  
Interstellar Dust ◽  
Theoretical Models ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Theoretical Studies ◽  
Interplanetary Dust Particles ◽  
Ir Reflection ◽  
Grain Surface

Recent observational and theoretical studies of dust in dense clouds are reviewed with an emphasis on the growth of dust grains through accretion and coagulation. IR reflection nebulae around protostellar objects are useful probes of grain sizes in dense clouds. For example, detailed studies of the IR reflection nebula surrounding OMC 2-IRS 1 show that the (scattering) grains are much larger (Ã 5000 å) than in the diffuse interstellar medium. Likewise, the presence of a weak shoulder at 2.95 μm on the 3.08 μm feature in BN indicates the importance of scattering by icy grains and implies a very similar increase in the grain size.Theoretical studies of grain surface chemistry predict the possible presence of three distinctly different grain mantle components in dense clouds depending on the physical conditions in the gas phase. These are: 1) A hydrogenated mantle dominated by H2O and CH3OH; 2) An inert grain mantle dominated by CO and O2; and 3) An oxidized grain mantle dominated by CO2. Although the importance of H2O dominated grain mantles was known for 10 yrs, the presence of CH3OH was only recently confirmed. Furthermore, recent studies of the solid CO band have revealed the presence of at least two distinctly different interstellar grain mantle components along the line of sights towards most stars: One dominated by polar and one by non-polar molecules. Although specific identification of the molecules mixed in with the CO in these components is difficult, it is quite possible that the former component is dominated by H2O and the latter by CO itself, as suggested by theoretical models. Finally, the photochemical evolution of icy grain mantles is briefly reviewed and it is suggested that the resulting complex molecular mantles may evolve into amorphous carbon mantles in the diffuse ISM.Grain-grain collisions can lead to large modifications of the interstellar grain size distribution. At high velocities (v ≳ 1 kms−1) shattering into many small fragments will be important, while at low velocities (v ≲ 10 ms−1) coagulation dominates. Both processes can play a role in dense molecular clouds. The sticking of grains at low velocities is discussed in some detail and it is concluded that coagulation in molecular clouds is only important if the colliding grains are covered by icy grain mantles.Thus, a model for interstellar dust is proposed in which small (≲ 500 å) silicate and carbonaceous grains are “glued” together in large (Ã 3000å), open conglomerates by a polymerized, all enveloping grain mantle. This structure resembles that of certain interplanetary dust particles collected in the upper stratosphere.

scholarly journals Scattering, absorption, and thermal emission by large cometary dust particles: Synoptic numerical solution

2019 ◽  
Vol 631 ◽  
pp. A164 ◽  
Author(s):  
Johannes Markkanen ◽  
Jessica Agarwal
Keyword(s):  
Light Scattering ◽  
Numerical Solution ◽  
Electromagnetic Waves ◽  
Random Media ◽  
Thermal Emission ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Conductive Heat ◽  
Interplanetary Dust Particles ◽  
Cometary Dust

Context. Remote light scattering and thermal infrared observations provide clues about the physical properties of cometary and interplanetary dust particles. Identifying these properties will lead to a better understanding of the formation and evolution of the Solar System. Aims. We present a numerical solution for the radiative and conductive heat transport in a random particulate medium enclosed by an arbitrarily shaped surface. The method will be applied to study thermal properties of cometary dust particles. Methods. The recently introduced incoherent Monte Carlo radiative transfer method developed for scattering, absorption, and propagation of electromagnetic waves in dense discrete random media is extended for radiative heat transfer and thermal emission. The solution is coupled with the conductive Fourier transport equation that is solved with the finite-element method. Results. The proposed method allows the synoptic analysis of light scattering and thermal emission by large cometary dust particles consisting of submicrometer-sized grains. In particular, we show that these particles can sustain significant temperature gradients resulting in the superheating factor phase function observed for the coma of comet 67P/Churyumov–Gerasimenko.

Sign in / Sign up

Export Citation Format

Share Document