The last regular posting of 2006 is a good time to remind you that Tammy Plotner's What's Up 2007 is now available. It's a 410 page PDF file that takes you through celestial events on a day to day basis for the entire year. Loaded with photographs and charts, What's Up 2007 is free to download, or you can buy a printed version for $25. A third alternative is to check the Astronomy What's Up weblog daily, where each day's entry will be posted as the year progresses. I skipped ahead at random and landed on February 14, which I learned from Plotner's book is not only Valentine's Day but also the birthday of astronomer Fritz Zwicky, who catalogued galaxy clusters and did yeoman work on supernovae. The celestial object for the day is the Spirograph Nebula, whose image (taken by the Hubble telescope) adorns the page. Plotner's clear prose walks us through the basics: ...the light you see tonight from the IC 408 planetary nebula left in the year 7 AD. Its central star, much like our own...

Interesting things happen when gravitational lenses go to work. The earliest observations of the phenomenon involved entire clusters of galaxies. When the alignment is right, a galaxy cluster between the observer and a still more distant galaxy will bend the light of that galaxy. It will appear as one or more luminous arcs which are actually made up of its multiple images distorted (and magnified) by the gravitational lens. All this happens because, as Einstein told us, spacetime is curved by the presence of matter. Here's how gravitational lensing looks. Notice the blue arcs of the lensed galaxy in the background surrounding the galaxies at their center, which have distorted spacetime enough to make this image possible. The latest work on the lensing phenomenon focuses on smaller structures like groups -- rather than entire clusters -- of galaxies. Astronomers using the Canada-France-Hawaii Telescope (Hawaii) are devoting 500 nights of telescope time to a survey of an area of the...

What were the first objects in the universe? They may have been enormous stars a thousand times more massive than the Sun. If so, new observations suggest the apparent clusters found by the Spitzer Space Telescope could be the first galaxies, tiny by Milky Way standards and containing the mass of less than a million Suns. By contrast, the Milky Way today seems to house at least a 100 billion stars, and may be the result of the merging of far smaller galaxies like these. This is remarkable stuff. Spitzer is looking at patchy infrared light found across the entire sky, light that comes from vast objects more than 13 billion years away. That number catches the eye, of course, because the universe is now thought to be some 13.7 billion years old. The light, which is either from stars or violent black hole activity, was once ultraviolet or optical, but the expansion of spacetime has stretched it into the infrared. Image: The right panel is an image from NASA's Spitzer Space Telescope of...

What got me interested in Pismis 24-1 was simply the image. It's one of those spectacular displays we've come to expect from Hubble, obtained using the telescope's Advanced Camera for Surveys. Pismis 24-1 is part of the open cluster Pismis 24, some 8000 light years from Earth in the nebula NGC 6357 in Sagittarius. The cluster is filled with massive stars, but what seizes the attention is the juxtaposition of the cluster itself (the brightest stars in the image) and the gorgeous tapestries of the nebula in which it is embedded. Pismis 24-1, the brightest star in the cluster, was originally thought to weigh up to 300 solar masses, making it twice the assumed upper mass limit for individual stars. But as the image below shows, it's at least a binary, and ground based observations suggest that it may even be a triple system, with the third star too tightly bound to be resolved. If so, it's a whopper of one, each of the three stars averaging about 70 solar masses. Ahead for these...

It's a gorgeous day in the mid-Atlantic states following one of the most colorful autumns in memory. Most of the leaves are down now, which gives me plenty to do. I had intended to look at the new paper from the California & Carnegie planet finder team, but the great outdoors beckons. Instead, we'll examine their latest next week, along with more on interstellar flight scheduling with reference to Marc Millis' recent presentation at Princeton and an intriguing Fred Hoyle insight. For today, here's a quick post on how adaptive optics can sharpen a telescope's view. In the image below, you're seeing two views of the part of the Orion Nebula known as the Trapezium. The Subaru telescope on Mauna Kea (Hawaii), working without adaptive optics, obtained the image on the right back in 1999. The image on the left shows the effect of a new laser guide star system and enhanced AO, and as you can see, the difference in detail is remarkable. Be sure to click to enlarge both views. Image: The...

Following up on this morning's post re cosmic rays and the early Earth comes news that the Chandra X-ray Observatory has mapped cosmic ray acceleration in Cassiopeia A, a 325-year-old supernova remnant. The map, showing that electrons are being accelerated close to a theoretically maximum rate, provides evidence that supernova remnants are major contributors of energetic charged particles like cosmic rays. "Scientists have theorized since the 1960s that cosmic rays must be created in the tangle of magnetic fields at the shock, but here we can see this happening directly," said Michael Stage of the University of Massachusetts, Amherst. "Explaining where cosmic rays come from helps us to understand other mysterious phenomena in the high-energy universe." Image: This extraordinarily deep Chandra image shows Cassiopeia A (Cas A, for short), the youngest supernova remnant in the Milky Way. New analysis shows that this supernova remnant acts like a relativistic pinball machine by...

Though I hadn't planned another entry for today, this is just too beautiful to pass up. We're looking at the Orion nebula (be sure to click the image to enlarge) in infrared, ultraviolet and visible light, a composite using both Hubble and Spitzer data that brings out unheard of detail -- the green swirls are from Hubble's ultraviolet and visible light detectors; the red and orange are Spitzer working in the infrared. This massive star formation region located in the sword of Orion is home to about 1000 young stars. Note the set of stars called the Trapezium, identifiable as a bright area near the center of the image. Each of these massive stars pours out ultraviolet that heats hydrogen and sulphur in the nebula. The stellar wind from clusters of stars embedded in the dust and gas helped to create the distinctive shapes and swirls of this celestial artwork.

Imagine our Sun spewing out a flare 100 million times stronger than usual, releasing the energy of 50 million trillion atomic bombs. The effect on our planet would be catastrophic. Fortunately, what the Swift satellite has spotted occurred a bit further away in a binary system called II Pegasi, some 135 light years from Earth. Swift is designed to detect gamma-ray bursts -- the most powerful of all explosions -- and this flare was energetic enough to produce a false alarm for such a burst. NOTE: The original entry here referenced the power of 'fifty trillion' atomic bombs; the actual figure used by NASA was corrected, as above, to 'fifty million trillion.' Thanks to Robin Goodfellow for catching the typo. II Pegasi is an interesting system. The flare star is 0.8 times the mass of the Sun; its companion is 0.4 solar masses, and the stars are separated by only a few stellar radii. That produces fast rotation on both stars, and while II Pegasi may be a billion years older than the Sun,...

Learning how interstellar dust turns into stars is a major challenge. But the AKARI satellite, an infrared observatory created by the Japan Aerospace Exploration Agency, could become a breakthrough tool in these studies. Launched in February of this year, AKARI is engaged in an infrared All Sky Survey, with spectacular early results from the Large Magellanic Cloud. The far-infrared image shown below shows that clouds of dust are found throughout this satellite galaxy of the Milky Way. Image: This false-colour view of the Large Magellanic Cloud is a composite of images taken by AKARI at far-infrared wavelengths (60, 90 and 140 microns). The Large Magellanic Cloud is a neighbour galaxy to the Milky Way. Interstellar clouds in which new stars are forming are distributed over the entire galaxy. The bright region in the bottom-left is known as the 'Tarantula Nebula' and is a productive factory of stars. Credit: JAXA. Infrared is ideal for these studies because stars tend to form within...

US readers should be aware of Monster of the Milky Way, a PBS program on Nova that's scheduled to air tomorrow evening. It's about the search for supermassive black holes in the center of galaxies and ties in nicely with this morning's post on galactic jets. Those of you with high-definition sets are in for a treat, though you may wind up taping it if the doorbell gets active enough on Halloween. The show runs at 8:00 Eastern time.

M 87, an elliptical galaxy 50 million light years away in the constellation Virgo, houses a gigantic black hole. The object amounts to 3 billion solar masses and is apparently the source of the huge jet of particles and magnetic waves shown in the image below. That conclusion comes from work proceeding in Namibia as part of the HESS (High Energy Stereoscopic System) collaboration, where scientists have detected sudden changes in M 87's emission of very high energy (VHE) gamma rays. Image: The radio galaxy M 87 seen in visible light. The central region, from which the VHE gamma rays are seen, is located in the upper left part of the image and the relativistic plasma jet extends to the bottom right. Credit: Hubble Space Telescope (HST). The variability in gamma ray emissions is interesting because it tells us about the size of the region producing the rays. There seem to be numerous ways to accelerate particles in a galaxy like M 87, but now we know that the actual source is an area...

Here's something to think about, or better, try to visualize on an evening when there's good celestial viewing outside. A typical globular star cluster holds several hundred thousand stars. Out on the periphery of such systems, the stars are relatively widely spaced. But move into the center and you'll find stars packed thousands of times tighter than in our Sun's neighborhood. Imagine the view in such a place -- 10,000 stars closer to us than Alpha Centauri turning the night ablaze. The Hubble Space Telescope paints this picture of conditions in the globular clusters that surround the Milky Way. And as part of these findings, the scientists involved say that such clusters sort out their stars on the basis of mass. You can imagine that in that tightly packed center, close encounters, collisions and mergers between stars would not be uncommon. The result: heavier stars sink toward the cluster's core, while lighter ones move eventually to the periphery, a process never before witnessed...

Next week we'll take a look at some interesting new work on the formation of rocky worlds around red dwarfs (including what might show up in the habitable zone around such stars), and a French study on the characteristics of gas giant exoplanets. I also want to talk about a new SETI attempt looking for signal leakage from a nearby solar system rather than directed beacons. For the weekend, though, ponder a project to get the public involved in deep sky astronomy by using the Internet to deliver live video of observing sessions. The company involved, Astrochannels.com, is still in beta testing, but the plan seems to be to stream views of galaxies, globular clusters, nebulae and other intriguing objects, along with a commentary, during scheduled live showings. Users will be able to vote on objects to be studied and participate in online forums. The next showing is tonight starting at about 10:20 Eastern time (0220 UTC), with the viewing schedule available here (Comet SWAN is an...

There are images that need to be appreciated slowly, the way you sip a rare wine. They should be carried with you a while, pondered, mulled over, and sometimes, as happened to me last night, they slip into your dreams. That dream was powerful enough to push the image below into today's entry. It's a snapshot of 28 galaxies, all of them close to 13 billion years old, factories of star formation whose intense blue light has been red-shifted to the ancient hue we see today. All told, the astronomers doing this work have found more than 500 galaxies that existed less than a billion years after the Big Bang. This vista follows up an earlier story in these pages describing work done by Rychard Bouwens (UC-Santa Cruz) and colleagues, who worked with the Hubble Ultra Deep Field and the Great Observatories Origins Deep Survey fields in their analysis of early galaxy formation. They believe these galaxies were producing stars at a rate ten times faster than we observe in nearby galaxies....