The silicates that produce the 10 and 18 micron features appear to be broadly similar to terrestrial minerals such as Forsterite and Enstatite. ... Where pre-solar silicate dust grains can be isolated from meteorite material, these also tend to be Mg-rich silicates rather than Fe-rich silicates. ... It has been suggested that the interstellar silicate grains have a different 10 micron feature profile than what is observed for the silicates around evolved stars. ...

... 2005 August 8 . Mars to Appear Normal This August . ... Regardless of numerous urban legends circulating, Mars will appear relatively normal in August. October is the best month to see Mars this year. ... As Earth catches up to Mars in their respective orbits around the Sun, Mars will keep rising earlier in the night. On 2005 October 30, Earth will have caught up to Mars and the planets will be the nearest to each other in their orbits -- this time around. ... About APOD | ...

... Tonight's Sky . ... Sky this Month . ... Star Atlas . ... stars . ... The Sky This Week: April 1 - 10 . ... Observing springtime deep-sky objects with a large telescope . ... Why do some stars appear to flash a variety of different colors when you look at them through a telescope? ... So, Earthт??s atmosphere will bend some colors from especially bright stars more so than others, which makes the source look like itт??s flashing colors. Get instant access to subscriber content on Astronomy.com! ...

... Using the DRAO Synthesis Telescope (Landecker et al. 2000), the Canadian Galactic Plane Survey ( CGPS ; Taylor et al. 2002) has captured a multitude of HISA features, the majority of which are invisible in prior surveys at lower resolution. ... Since the HISA gas temperature must be less than the background brightness temperature, all the H I shown in this poster has T ~ 100 K. Figure 1 provides panoramic views of the cold H I visible as HISA in the CGPS. ... GIFs: HISA + CO | HISA only | ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... SEARCH ASP SITE: Match ALL words Match ANY word . ... ASP Conference Series . ... Accidental Astrophysics: The Devil's In the Magnitudes, Part II . ... The star second to the Sun in brilliance is Sirius. ... Recall the magnitude system, passed down to us through a hundred generations of sky watchers, as a means of quantifying stellar brightness ("Accidental Astrophysics," May/June, p. 9). ... Yes, it is a magnitude difference, but that difference is due to the distance between us and the star. ...

... In the Center of Spiral Galaxy M61 . ... M61 is a barred spiral galaxy located in the nearby Virgo Cluster of Galaxies. Visible in M61 are a host of features common to spiral galaxies: bright spiral arms, a central bar, dust lanes, and bright knots of stars. ... Jupiters Great Red Spot from Voyager 1 . ... What will become of Jupiter's Great Red Spot? ... It's also known for a giant swirling storm system, the Great Red Spot, featured in this sharp Hubble image from April 21. ...

2009-05-20 O.Hainaut There are many steps between the data coming out of a camera on a professional telescope and the final image that appears in magazines or on our web sites. ... preliminary: from the telescope to Photoshop. cleaning: remove the artifacts remaining in the image . ... In each filter, several images are acquired. ... Fig 1: a raw image (click for full scale) . ... At this stage, the images are still in FITS, the astronomical format, with one FITS file per filter. ... The final image. ...

... July 13, 1999 . The Flame Nebula in Infrared . ... Explanation: What lights up the Flame Nebula? Fifteen hundred light years away towards the constellation of Orion lies a nebula which, from its glow and dark dust lanes, appears like a billowing fire. ... Rather the bright star Alnitak , the easternmost star in the Belt of Orion visible to the nebula's right, shines energetic light into the Flame that knocks electrons away from the great clouds of hydrogen gas that reside there. ...

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. ...

... The HH flow associated with young stellar object HL Tau has an exciting history and even until now the origin of some its features is not clear yet. ... Knotty structures of Herbig-Haro jets are common phenomena and knowing the origin of such structures is essential for understanding the processes of jet formation. ... In the flow detected compact knots with high (-150 km/s) and bow shape structures in front of those, with low radial velocities (-50 km/s). ...

... A detailed study of two consecutive bright points observed simultaneously with CDS, EIT and MDI is presented. The analysis of the evolution of the photospheric magnetic features and their coronal counterpart shows that there is a linear dependence between the EIT Fe XII 195? flux and the total magnetic flux of the photospheric bipolarity. ... In a follow-up study, we used wide slit (90arcsec240arcsec) movies of four EIT coronal bright points (BPs) obtained with CDS. ...

Galaxies are diffuse objects which are imaged against a background of finite brightness and noise. Galaxies which have the maximum contrast with respect to this background are the ones that are first discovered. ... These galaxies have been missed to date but active surveys for them are underway. ... In this page we present several examples of these newly discovered Low Surface Brightness galaxies as well as examples of high surface brightness galaxies. ...

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. ...

... X CB (X) Opening of a set X by a disk B. Closing of a set X by a disk B. Science-Driven Feature Selection (a) (b) Mount Wilson Classification The Mount Wilson classification scheme groups sunspots into four classes based on the complexity of magnetic flux distribution in associated active regions [1]: class : groups dominated by a single unipolar sunspot class : a pair of sunspots of opposite magnetic ... Convex hulls are utilized to measure polarity mixture in (j). ...

A team of U.S. and German astrophysicists have made the first ever detection of X-rays coming from a comet. ... Following the initial detection, the team reported repeated X-ray emissions from the comet over the next 24 hours. ... One preliminary theory is that X-ray emission from the Sun was absorbed by a cloud of gaseous water molecules surrounding the nucleus of the comet, and then were re-emitted by the molecules in a process physicists call "fluorescence." ... Comets . ...

The antenna element Ravi ATNF, Narrabri 1. ... Miriad works out the radio Parabolic reflector: A parabolic reflector adds all the fields from a surface = aperture at a focal point. ... Feeds are `compact' and `corrugated' horns The inner profile is curved The inner surface has grooves Cross-section of a horn Sub-reflector 28 main-reflector Feed horn O `optical axis' The feed horn adds all the rays that come from the 28 deg. wide sub-reflector. The feed down-weights rays that come off-axis. ...

... Imaging of the core of the OMC-1 region using NICMOS camera 2 through the F212N and F215N filters shows a wide variety of interesting structure on scales of 0.2" at a very high dynamic range (Stolovy et al. ... The application of image restoration techniques, including multi-channel variants of the Richardson-Lucy technique, offers the chance to enhance structure on the finest scales and also to suppress the prominent and richly structured point-spread functions of the many bright stars in the...

... Since the fast mode window is necessarily small, the source PSF fills much of the window (clearly evident for bright sources). ... As such, the source and background extraction apertures may be truncated by the window. ... While often there will be only one object in the image, one should check for spurious detections which could affect the analysis of the target source and also for missed sources or prominent objects in the window, which may contaminate the target. ...

... 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. ...