Space Sci Rev (2007) 132: 1–182 DOI 10.1007/s11214-007-9224-0 Astrophysics in 2006 Virginia Trimble · Markus J. Aschwanden · Carl J. Hansen Received: 11 May 2007 / Accepted: 24 May 2007 / Published online: 23 October 2007 © Springer Science+Business Media B.V. 2007 Abstract The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the Universe) and others of which there are always many, like meteors and molecules, black holes and binaries. Keywords Cosmology: general · Galaxies: general · ISM: general · Stars: general · Sun: general · Planets and satellites: general · Astrobiology · Star clusters · Binary stars · Clusters of galaxies · Gamma-ray bursts · Milky Way · Earth · Active galaxies · Supernovae 1 Introduction Astrophysics in 2006 modifies a long tradition by moving to a new journal, which you hold in your (real or virtual) hands. The fifteen previous articles in the series are referenced oc- casionally as Ap91 to Ap05 below and appeared in volumes 104–118 of Publications of V. Trimble Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575, USA e-mail: [email protected] V. Trimble Las Cumbres Observatory, Santa Barbara, CA, USA M.J. Aschwanden () Lockheed Martin Advanced Technology Center, Solar and Astrophysics Laboratory, Organization ADBS, Building 252, 3251 Hanover Street, Palo Alto, CA 94304, USA e-mail: [email protected] C.J. Hansen JILA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309, USA e-mail: [email protected] 2 V. Trimble et al. the Astronomical Society of the Pacific. The ground rules are fairly simple: we read a lot, decide what we think is important, and tell you about it. Used in compiling Sects. 3–6 and 8–13 were the issues that arrived as paper between 1 October 2005 and 20 Septem- ber 2006 of Nature, Physical Review Letters, Science, Astrophysical Journal (plus Letters and Supplements Series), Monthly Notices of the Royal Astronomical Society, Astronomy and Astrophysics, Astronomical Journal, Acta Astronomica, Revista Mexicana Astronomia y Astrofisica, Astrophysics and Space Science, Astronomy Reports, Astronomy Letters, As- tronomische Nachrichten, Publications of the Astronomical Society of Japan, Publications of the Astronomical Society of the Pacific, Journal of Astrophysics and Astronomy, Bul- letin of the Astronomical Society of India, Contributions of the Astronomical Observatory Skalnate Pleso,andIAU Circulars. Read less systematically (sometimes because only spo- radically available) and cited irregularly were Observatory, Astrofizica, New Astronomy (plus Reviews), Journal of the American Association of Variable Star Observers, Astronomy and Geophysics, Mercury, New Scientist, Science News, American Scientist, Scientometrics, Monthly Notes of the Astronomical Society of South Africa,andJournal of the Royal Astro- nomical Society of Canada. Additional journals provided material for Sects. 2 and 7,and are mentioned there. Many of the discussions start with (but move in random directions from) some particu- larly exciting item, which is described as deserving a green circle (the identifier in the senior author’s notebook) or gold star or red flag. It is not required that the reader agree with us (though experience indicates that the authors cited quite often do). 1.1 Up Some of these are launches, some first lights or extended operations, and others miscella- neous good news. • ESA’s Venus Express was launched from Baikonur on 9 November 2005 and entered orbit on 11 April, though apparently with a spectrometer mirror jammed (Science 312, 827). • SALT (South African Large Telescope) was officially opened in November, 2005 (Na- ture 438, 18; also reporting the curious factoid that Richard Woolley was the only South African born director of SAAO to date; and yes, they missed the chance to appoint a very good one this time around). First light comes later. • Auger caught its first ultrahigh energy cosmic rays in November (Nature 438, 270). The facility is safely back in Argentina from an unknown site in Chile, to which one of your authors accidentally transported it in an earlier review. • Japan began putting CO2 samplers on commercial flights in November (Nature 438, 266) with the intention of providing closely spaced four-dimensional data. • The secular (as opposed to ApXX) year ended with the launch of the first satellite of the European GPS equivalent on 28 December. • Stardust returned safely on 15 January (Nature 459, 255), though what it was carrying was really comet dust, from Wild 2, and the connection with Woolley, just mentioned, is in name only. • New Horizons took off for Pluto on 19 January. • A successful launch of ASTRO-F, the second Japanese infrared satellite on 21 February led to its being renamed AKARI. First light was on 13 April, and an all-sky survey is underway. • FUSE was back up and working in February 2006. • Cerro Pachon was chosen as the site for the Large Synoptic Survey Telescope in March (Nature 441, 397). LSST will not be lonesome, since Gemini South and SARS are already there. We confess to having rooted for San Pedro Martir. Astrophysics in 2006 3 • April was an uncruel month, with initial operations of CARMA (the union of radio mil- limeter facilities made out of OVRO and BIMA, Nature 441, 141), the initiation of optical SETI at Oak Ridge Observatory (Harvard), and the first 10 dishes of the Allen (SETI) Telescope Array in place at Hat Creek. Rebuilding of Mount Stromlo Observatory is in progress (Science 312, 684), with the Great Melbourne Telescope to become Sky Map- per and the reconstructed near infrared integral field spectrograph already dispatched to Gemini. • The operation of SoHO was extended to 2009 in a May decision (Nature 441, 562). It sometimes discovers sun-grazing comets as well as So’s and Ho’s. • Construction began at about the same time on Antares, a French neutrino detector under the Mediterranean (Science 312, 1305). International collaborations are hard at work try- ing to figure out how to distinguish French neutrinos from those of other nationalities. We suspect it has something to do with the flavor. • PAMELA took off from Baikonur on 15 June (Nature 441, 920). Its job is to look for positrons and anti-protons in cosmic rays from any source. • MAGIC (which detects TeV photons by Muggle1 methods) has seen a source known also to HESS and INTEGRAL (ApJ 637, L41). As it is the largest single-dish atmospheric Cerenkov detector and the authors ranged from Albert to Zapatero, this item could have appeared in several other sections. • The Japan Aerospace Exploration Agency (JAXA) launched the Sun-observing satellite Solar-B on September 23 and renamed it to Hinode, the Japanese word for sunrise. Its sharp vision with 0.2 arc-second resolution makes it like a “Hubble for the Sun” (NASA press release). • Awards given in September by the Astronomical Society of the Pacific included outreach and amateur achievement to colleagues from Iran and the Czech Republic. • APEX, the Atacama Pathfinder Experiment at Chajnantor produced a package of 20 sci- entific letters (A&A 454, L13 and following). We would have called the facility a trial balloon for ALMA, but even our linguistically elastic minds rebelled at that bit of cogni- tive dissonance. • The World/International Year of Astronomy in 2009 will also see Darwin’s 200th birthday (12 February, just like A. Lincoln) and the 150th anniversary of publication of Origin of the Species. The competition will surely be good for science education in general, though perhaps bad for astronomy specifically. Students have reminded us that, in addition to the first telescope observations, 1609 also witnessed the publication of Kepler’s New Astronomy (which made him something like the 14th Copernican in world history). • NASA announced a selection of Discovery Program concepts for future study. They are an asteroid sample return, Venus chemistry and dynamics orbiter, mapping of gravitational fields on the moon, and possible continuing use of DeepImpact to fly to a second comet or revisit Temple 1 and look for changes since it Deeply Impacted. 1.2 Down We have not succeeded in putting these in chronological order, and indeed were in some cases undecided whether a particular entity belonged here or in Sect. 1.3. 1Anyone who hasn’t heard that muggles are non-magicians in the series of novels centered on Harry Potter probably isn’t going to like this review very much anyway. 4 V. Trimble et al. • The last Western Union telegram was sent on 27 January 2006 (Los Angeles Times,8Feb- ruary, p. B13). The first came on 24 May 1844 from Samuel F.B. Morse. Nokia will keep its SMS (Short Message Service) in Morse. What this means for astronomy is that if NAS Domestic Secretary Abbott were attempting to stage the Curtis-Shapley debate this year, he would have to figure out some other way to invite the participants. • China has stopped selling lunar real estate for $37 per acre (Nature 438, 269). We missed our chance to buy some but have hopes that stones from the Great Wall might make their appearance on the open market, like the ones from London Bridge some years ago (yes; it serves as a candle snuffer). • Marshall Field disappeared into Macy’s this year and will be mourned by all who remem- ber The Imperturbability of Elevator Operators by S. Candlestickmaker. Overcivility may never happen again (Hecht’s, Filene’s, Woodward and Lathrop, Robinsons,andThe May Company, where Mary Livingston worked, are other recent losses).