In early mid-infrared observations (c 1970) two prominent dust emission features were discovered. ... Soon after the discovery of the silicate features another feature at about 11.3 microns was discovered in the spectra of some carbon stars, not as wide or as strong as the silicate features but still thought to be due to a solid material. ... less common features: extreme carbon stars, the AlO/silicate complex, the "unidentified infrared" features, unusual silicate features . ...

... Laboratory and theoretical modelling of the UV bump on the interstellar extinction curve is a very popular topic in dusty investigations. ... feature is illustrated by Fig. 10 where the profiles were calculated using the model of graphite spheres. Figure 10: Normalized extinction efficiencies for graphite spheres. ... The lower panel shows the summary extinction of two graphite spheres with radii and (from upper panel) taken in equal proportions. ...

Next: Radial velocity of the Up: Optical spectrum of IRAS04296 Previous: Observations and spectra reduction . ... However, molecular emission features are only very rarely observed in the optical spectra of PPNe. ... On the other hand, it is well known that cometary nuclei spectra show prominent Swan band emission. In both spectra of IRAS04296 we have discovered strong emission in the (0;0) and (0;1) bands of the Swan system of the molecule. ... Now consider the case of IRAS04296. ...

... Up: Data Analysis and Processing Techniques . ... Also, a method for quality control of CCD observations is suggested. ... Everyone who observes a celestial object using a CCD detects moving celestial objects as a ``by product''. ... We hope that our investigations may be useful for near-Earth space control and also for searches of the moving celestial objects through analysis of old and new CCD frames obtained at any amateur or professional astronomical observatory. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Armagh Planetarium . ... Stars . ... Space Flight . ... Monthly Sky Notes . ... NGC 6357's inner star forming region glows with the emission of ionized hydrogen gas. Image credit: ESO/VVV Survey/D. Minniti. ... Located around 8000 light years away in the constellation of Scorpius , NGC 6357 (sometimes called the Lobster Nebula ) is a typical stellar nursery, filled with vast clouds of gas and tendrils of dark dust. ... Subscribe to Astronotes . ...

Proposal Identi cation No.: R1116 Date Received: 1998-Feb-13 02:32:50 Technical Page Proposal Type: Regular General Category: Planetary Radar Observation Category: Solar System Total Time Requested: 42 Hours Proposal Title: Radar Imaging Observations of Mercury in the Summer of 1998 ABSTRACT: We propose to make radar-imaging observations of Mercury using the random-code technique. ... Maybe Part of the observing run. ...

... If finddead =Y, embadpixfind looks for too dark pixels, rows and columns too. ... The maxratio parameter avoids detecting 'grey' pixels, rows or columns on observations with high statistics. Whatever findbright and finddead , dark and bright columns and rows are always searched for together in order of decreasing significance (either positive or negative). This avoids finding spurious bright columns/rows next to very dark ones, and vice-versa. ...

... We have started a programme of observations of nearby starburst and AGN galaxies with MICHELLE, with the aim of investigating the spatial extent of "Unidentified Infrared Bands (UIB)" emission in these galaxies, and in particular relating these to multi-frequency matched resolution radio maps. ... The spatially integrated MICHELLE spectrum of NGC 7469 in the 8 - 11.5µm range shows an equivalent width of 11.3µm UIB feature which is much smaller then measured by ISO. ...

We present broadband photometry in the optical, near infrared and sub-millimetre, and mid-infrared spectrophotometry of a selection of carbon stars with optically thin envelopes. ... Beside the emission features at 11.3 \mu m due to silicon carbide grains in the circumstellar environment, many of our mid-infrared spectra show an emission feature at 8.6 \mu m. All the observed spectral energy distributions exhibit a very large far-infrared flux excess. ...

... The presence of solid­state emission bands is compared to other indicators of circumstellar material, such as Hff emission, optical variability and sub­mm continuum fluxes. ... However, a strong dependence on spectral type of the central star seems to be present: stars with spectral type earlier than B9 show either amorphous silicate in absorption or infrared spectra dominated by PAH emission, whereas more than 70% of the stars of later spectral type show silicate emission. ...

Next: Coordinate Systems Up: IRAF/PROS Previous: Other Types of Files . A few new features and enhancements to the standard IRAF system have been introduced with the PROS software: . ... Default compound extensions are used by the PROS tasks when no extension is given for the output file name. Most PROS tasks allow the output file name to be defaulted, with the convention that the output file name will be composed of the input `root' name, plus the default extension specific to the task. ...

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Solar High Resolution Studies . ... Solar Group . ... High quality observations obtained in recent years have highlighted the fact that the solar atmosphere is extremely dynamic, and wholly permeated and shaped by magnetic fields at very small spatial scales. ... The Solar Group in Arcetri is initiating a project to study some of the topics and techniques that will be brought to the forefront of solar physics as this new physical regime is explored. ... Small Scale Activity . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2016 March 7 . Mystery Feature Now Disappears in Titan Lake . ... Explanation: What is that changing object in a cold hydrocarbon sea of Titan? ... In an image released last week, the mystery object seems to have disappeared in 2015 January. The featured false-color image shows how the 20-km long object has come, changed, and gone. ...

... Mystery Feature Now Disappears in Titan Lake . ... Credit Copyright: Cassini Radar Mapper , Cornell , JPL , ESA , NASA Explanation: What is that changing object in a cold hydrocarbon sea of Titan? Radar images from the robotic Cassini spacecraft orbiting Saturn have been recording the surface of the cloud-engulfed moon Titan for years. ... In an image released last week, the mystery object seems to have disappeared in 2015 January. ... Publications with keywords: Titan . ... Soaring over Titan . ...

Analysis of polar motion variations from 170-yearobservation series . ... Pulkovo Observatory, St. Petersburg, Russia Abstract: . This work is devoted to investigation of low frequency variations in Polar motion (PM). It has been shown that the main PM features can be effectively investigated using not only time series of the Pole coordinates, but also using series of latitude variations obtained from observations at one observatory. ... polar motion, harmonic, Chandler wobble. ...

... Tonight's Sky . ... SUN MOON MERCURY VENUS MARS, JUPITER SATURN . ... Observing . ... Astronomy for Kids . ... MAVEN spacecraft returns first Mars observations . ... NASA s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has obtained its first observations of the extended upper atmosphere surrounding Mars. ... MAVEN is the first spacecraft dedicated to exploring the tenuous upper atmosphere of Mars. ... Only registered members of Astronomy.com are allowed to comment on this article. ...

... Column 1 gives the object name from the Case or Markarian catalogs. ... For Markarian galaxies the errors of coordinates usually lie inside 2'' (Lipovetsky [ 1983 ]). Column 4 gives the eye-estimated apparent blue magnitudes according to the same sources. ... Other names of a galaxy we give in column 7. ... In column 3 we cite the original emission-line code of the galaxy for the strength of [O III ] doublet according to the Case catalog (s - strong, m - medium, w - weak). ...

Subject, Problems and Objects of Theoretical Astrophysics. ... Stellar Photospheres, Their Features. ... Physics of Continuous Radiation Absorption in Stellar Photospheres. ... Continuous Radiation Absorption in Stellar Photospheres of Various Spectral Classes. Solar Type Photospheres. ... Characterisics of Absorption Lines. ... Interstellar Absorption Lines, Their Features. ... Physical and Dynamic Features of Interstellar Medium, Which Follows from Observations of Interstellar Absorption Lines. ...

... Contacts . 2012: . ... We refined the fundamental parameters of the components, the orbital periods, and the conditions of photospheric heating of the secondary component by the ultraviolet radiation of the hot component. ... The observations of the star clusters associated with ultra-luminous x-ray sources (ULXs) in four galaxies on the 6-meter and VLT telescopes have shown that all the ULXs are located within 200pc of very young star clusters (younger than 5 million years). ... Archive . ...