The purpose of this page is to provide a place for pictures which have been uploaded to my server, but have yet to be put on a specific page, for lack of time to write the text required to put them in proper perspective. In the meantime, they serve as 'eye candy', and through the links provided to their original Internet posting, an opportunity for viewers to read more about them before they are moved to their final destination. Because they will all be moved to another page, anyone who wants to link to one of these images should use the original posting, instead of this page. (In fact, since search engines take weeks or months to notice changes in the location of images, this page is gradually being phased out, as being more confusing than useful -- see Finding Pictures Which Have Been Moved, immediately below.) Also, before linking to or using material from this site on another website, read my Copyright and 'Fair Use' Notice.

At the center of the image below is the variable star LL Pegasi (also known as AFGL 3068) (RA 23 19 12, Dec +17 11 35), a binary star consisting of a carbon star (that is, a star with strong absorption features due to carbon atoms in its atmosphere) and a hotter, bluer star of uncertain type. The pair are hidden by thick clouds of dust and gas ejected by the cooler star (the nebular structure is referred to as IRAS 23166+1655), as the star (presumably) nears the end of its life. In other words, the star is thought to be in a pre-planetary nebular stage. Theoretical calculations indicate that in such binary systems, gravitational interaction of the companion with gases ejected by the dying star can create spiral structures, and LL Pegasi demonstrates the most spectacular example of such a structure, consisting of nearly 5 complete arcs around the star. The two stars are thought to be about 110 AUs apart, and orbiting each other once every 800 years or so (the distance and period are dependent upon estimates of the distance of the system, which is thought to be about 3000 light years, but is not at all certain). The orbits are presumed to be relatively eccentric, so that periastron passages involve considerably greater gravitational interaction than those which exist during other parts of the orbital motion. The connection between the orbital interaction and the spiral structure is thought to be confirmed by the rate at which the gas in the spiral structure is expanding (about 30 thousand miles per hour) and the distance between the spiral arcs; these suggest a periodicity of 800 years in forming the arcs, in agreement with the probable orbital period. The temperature of the spiral structure is only a few hundred degrees, far too low to create significant visible radiation at even a fraction of the distance to the system. As a result, even in this near infrared image, most of the light by which the structure is seen is believed to be the light of the Milky Way itself, reflected off the structure. For comparison purposes, the "bright" star to the north (above) the spiral is a 13th-magnitude object, and the many stars and galaxies seen in this image are barely visible in most views of the region, as shown in the comparison image, below. Image Credit: ESA, Hubble, R. Sahai (JPL), NASA

An artist's impression of the formation of a circumstellar disc around a star. Rotation of material falling toward the star causes it to form a circular disc surrounding the star (in the case of our Sun, this is referred to as the Solar Nebula). As material falls toward the star, it is heated and compressed. For smaller stars, most of the material may become part of the star; but for hot, bright massive stars (such as represented by this image) much of the infalling material is ejected into space, at very high velocity. Because of the density of the material in the circumstellar disc, the ejected material is forced to follow a path perpendicular to the plane of the disc, forming two "polar" jets. (Credit: L. Calçada/M. Kornmesser, ESO)

Gravitational lensing by galaxy cluster Abell 2218. This image will be moved to a fixed location later this year. For now, refer to apod100620 for more information. (Credit: Andrew Fruchter (STScI) et al., WFPC2, HST, NASA Digitally reprocessed: Al Kelly)

Light and dark streaks on slopes in Acheron Fossae, a depression named after an albedo feature (a region which stands out from its surroundings because it is lighter or darker than usual) on Mars. No one knows the reason for the dark streaks, but it appears that dark sand has run downhill almost like a liquid, coating the surface. Over time, the sand darkens, again for reasons unknown. As we observe Mars in more detail (in this case, with the Mars Reconnaissance Orbiter), we find more and more strange-looking features with no Earthly counterparts, and as a result, no obvious explanation. (HiRISE, MRO, LPL (U. Arizona), NASA, apod100301)

Galaxies imaged by the HUDF infrared camera on the Hubble Space Telescope, in the same region as the Hubble ultra deep sky survey of 2004, reveal faint red galaxies (mostly dots almost too small to see in this image) with redshifts of 8 or more. The thousands of brighter foreground galaxies, although interesting in their own right, are not as crucial to our understanding of the universe as the fainter, more distant galaxies, which may reveal the nature of galaxy formation in its earliest stages. (NASA, ESA, G. Illingworth (UCO/Lick & UCSC), R. Bouwens (UCO/Lick & Leiden U.), & the HUDF09 Team, apod091209)

The light from a distant (approximately 10 billion light-years away) quasar (Q2237+0305) is gravitationally lensed by an intervening spiral galaxy (about half a billion light-years away). In this particular case, the result is four dots, referred to as an Einstein cross. As stars in the nearby spiral move around, the lensing effect changes, causing changes in the brightness of the individual dots in periods of only a day or so. Other images of gravitational lenses are scattered elsewhere on this site, and will be combined with this one on a new page, in the near future. (Image taken in October 1999 by J.Rhoads, S.Malhotra, I.Dell'Antonio (NOAO)/WIYN/NOAO/NSF, apod100207; intervening galaxy brightness enhanced by Courtney Seligman)

An infrared image of the Small Magellanic Cloud shows a "tail" of gas (part of the Magellanic Stream), probably stripped from the SMC by gravitational interactions with the Large Magellanic Cloud, or our galaxy, and clusters of stars formed from the gas. (NASA, JPL-Caltech, STScI, apod100107)