Announcements

26 January 2006: Strong darkening observed around the equator of Vega suggests that the fifth brightest star in Earth’s sky has a huge temperature difference of 4,000 degrees Fahrenheit from its cool equatorial region to its hot poles. Jason Aufdenberg of NOAO led a team using the CHARA array on Mount Wilson to obtain this result. NOAO Press Release 06-03.

11 January 2006: A team led by a University of Florida astronomer has discovered a planet orbiting a star about 100 light-years from Earth. The star is just 600 million years old, one of the youngest stars ever found with a planetary companion. The discovery was made at Kitt Peak National Observatory with a new interferometric instrument called the Exoplanet Tracker (ET) that promises to greatly expand the efficiency of searches for new exoplanets.

9 January 2006: A team led by astronomers from CTIO has found faint visible echoes of three ancient supernovae by detecting their centuries-old light as it is reflected by clouds of interstellar dust hundreds of light-years removed from the original explosions. The oldest one is likely to have occurred more than six hundred years ago. More in NOAO Press Release 05-12. Additionally, the team has used the Gemini South telescope in Chile to obtain a detailed spectrum of an echo of light from an ancient supernova that enables them to identify the original star’s cause of death. More in NOAO Press Release 06-02.

4 January 2006: There are many milestones an astronomical observatory passes as it progresses through its scientific evolution. As the 2006 calendar year begins, Gemini Observatory has reached one of these important milestones: the publication of the 200th paper based on Gemini data. The paper which marks this event is titled “The luminosity function of the fossil group RX J1552.2+2013” by Claudia L. Mendes de Oliveira, Eduardo. S. Cypriano, & Laerte Sodré, Jr., The Astronomical Journal, 131, 158-167, 2006 January. For more details on the paper see the summary here. Of course this particular paper, like any of the 199 before it, only provides a glimpse at the diversity of research performed during Gemini’s early years. A scan of our publications archive reveals a range of research and discoveries that will continue to expand and diversify, creating a significant legacy for generations of scientists and members of the public. Many of these findings …

3 January 2006: Galaxy Clusters Galaxies frequently appear in large numbers as physical units bound by gravity. The largest are the galaxy clusters with hundreds of members, and at the smaller end are the compact groups of galaxies with a maximum of about 10 members. Between these are the “fossil groups” with members numbering in the dozens. A fossil group of galaxies is a system with a large extended x-ray halo, dominated by one very luminous elliptical galaxy that is surrounded by low-luminosity companions. Claudia L. Mendes de Oliveira (Universidade de Sao Paulo, Brazil) and her collaborators used GMOS, the optical imager/multi-object spectrograph on the Gemini North Telescope, to determine the first luminosity function (LF) of the galaxies in a fossil group based on spectroscopy of the member galaxies. The team observed the fossil group RX J1552.2+2013, and measured a mean redshift of z = 0.136 for 36 of its confirmed members. The …

28 December 2005: A team led by astronomers from CTIO has found faint visible echoes of three ancient supernovae by detecting their centuries-old light as it is reflected by clouds of interstellar dust hundreds of light-years removed from the original explosions. The oldest one is likely to have occurred more than six hundred years ago.

14 December 2005: More than half of the largest galaxies in the nearby universe have collided and merged with another galaxy in the past two billion years, according to a new study using hundreds of images from two of the deepest sky surveys ever conducted. The idea of large galaxies being assembled primarily by mergers rather than evolving by themselves in isolation has grown to dominate cosmological thinking. However, a troubling inconsistency within this general theory has been that the most massive galaxies appear to be the oldest, leaving minimal time since the Big Bang for the mergers to have occurred.

12 December 2005: NGC 1068 The Closest Active Galactic Nucleus NGC 1068 is located about 14.4 megaparsecs away, making it the closest and best-studied example of an active galactic nucleus (AGN). An AGN emits copious amounts of energy from its nucleus, from very energetic x-rays to long wavelength radio waves. In addition to the intense radiation field, the nucleus of NGC 1068 contains a large amount of highly ionized and fast moving gas. In fact, some of the gas has been measured moving at up to several thousand kilometers per second. The accepted view is that the high-energy photons and high speed of the gases are generated in the vicinity of a massive black hole at the very center of the galaxy which is thought to have a mass of several million times that of the Sun. Studying the properties of gas and hot dust in such environment is a powerful approach to …

2 December 2005: M31 is the nearest spiral galaxy to our own Milky Way, located a mere 2.2 million light-years distant. The Local Group Galaxies Survey team used the Mosaic camera on the Kitt Peak Mayall 4-meter telescope to investigate M31’s substantial population of young, massive stars over a very large field of view. Each of the squares in the image, featured on the cover of the December, 2005 NOAO Newsletter, is half a degree on a side, about the size of the full Moon.

22 November 2005: The instrument clusters located at the Cassegrain foci of the Gemini telescopes are perhaps the most unique collections of astronomical instrumentation ever assembled on ground-based telescopes. Each cluster contains as many as four specialized instruments, each of which observes in a particular wavelength regime. When fully populated, both Gemini North and South can observe from the optical, through the near-infrared, and into the mid-infrared, covering a wavelength range from 0.4 to 25 microns. The Gemini South complement of instruments contains the optical imager and multi-object spectrograph GMOS, the mid-infrared imager/spectrograph T-ReCS, the near-infrared spectrograph GNIRS, and the high resolution spectrograph Phoenix. In addition, the optical high-resolution spectrograph bHROS is located in the pier of the telescope and is fed by a fiber link from GMOS. At Gemini North, the optical imager and multi-object spectrograph GMOS, the mid-infrared imager/spectrograph MICHELLE, the near-infrared imager/spectrograph NIRI, and the "point-and-shoot" adaptive optics system ALTAIR …

21 November 2005: International team of North American and European scientists has just published the first set of spectra of high- redshift supernovae based on the Supernova Legacy Survey (SNLS) conducted with MegaPrime/MegaCam at the Canada-France-Hawaii Telescope. The results impact our understanding of dark energy, and have appeared in two scientific papers led by D.A. Howell (University of Toronto) and another by P. Astier (LPNHU, Centre National de la Recherche Scientifique (CNRS) and Universitis Paris VI & VII). A large fraction of the supernova spectra have been obtained with the Gemini telescopes. SNLS uses Type Ia supernovae as standard candles to study the acceleration of the universe. Programs are underway at Gemini and other large telescopes to characterize the dark energy driving this expansion by measuring its average equation of state, w = p/ρ. Dark energy is a new, unaccounted-for form of energy that opposes the self-attraction of matter (due to gravity) and …

17 November 2005: Coming up in January, Saturn will be at opposition, appearing at its largest in the skies of Earth. This image of Saturn and its moon Titan (lower right) was taken during the Kitt Peak Advanced Observing Program, using a set of stacked images from a Web cam on the Kitt Peak Visitor Center 20-inch telescope.

28 October 2005: The recent addition of a field lens in the Altair adaptive optics system has resulted in a significant improvement in near-infrared imaging capabilities at Gemini North. Altair with the field lens will begin regular science use in semester 2006A. Adaptive Optics - Straightening Bent Starlight Adaptive optics (AO) technology uses deformable mirrors to remove distortions to starlight caused by turbulence in Earth's atmosphere. Using this technology, astronomers can improve near-infrared images to rival the resolution of space-based observations. The technology is rapidly evolving and technologies such as laser guide stars and 3-dimensional turbulence mapping (multi-conjugate AO) are making the technology even more powerful. The lens was installed based on recent turbulence monitoring that demonstrated that about 60% of the turbulence on Mauna Kea occurs close to the ground. Altair was originally designed based on the assumption of a dominant turbulence layer at 6.5 kilometers. According to Gemini’s Associate Project Scientist …

19 October 2005: In this giant star-forming region, also called 30 Doradus, energy from hot, young stars creates dramatic voids and filaments in the surrounding gas. The nebula is located 160,000 light-years distant in the southern constellation Dorado, within the galaxy known as the Large Magellanic Cloud. This image was taken with the Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile, as part of the Magellanic Cloud Emission Line Survey (MCELS) project.

11 October 2005: A team of astronomers including NOAO scientists have used the Hubble Space Telescope to identify the source of a mysterious blue light surrounding a supermassive black hole in our neighboring Andromeda Galaxy (M31). The strange light has puzzled astronomers for more than a decade. Infrared image of the Andromeda Galaxy taken with the Mayall 4-meter telescope at KPNO.

5 October 2005: Based on Press Release from the University of Hawaii, Institute for Astronomy Astronomers using the Frederick C. Gillett Gemini Telescope on Mauna Kea have found the source of short flashes of gamma rays from outer space: a collision of two dead stars. For 35 years, astronomers have been fascinated by mysterious flashes of high-energy radiation from apparently random places in the sky. These events, known as gamma-ray bursts, were first discovered by U.S. military satellites designed to monitor nuclear tests in space. A typical burst lasts less than a few seconds, which makes them notoriously difficult to catch. In fact, until recently astronomers had been uncertain whether the bursts were coming from the solar system, the Milky Way, or distant galaxies. Because of this, research on the short bursts floundered for decades. However on July 9, 2005, Paul Price of the University of Hawaii Institute for Astronomy and Kathy Roth …

27 September 2005: Over the course of 14 dark nights at Kitt Peak National Observatory, more than 70 images of the Virgo galaxy cluster were taken by the Case Western Reserve University’s 24-inch Burrell Schmidt telescope. Advanced image processing techniques were used to combine the individual images into a single image capable of directly revealing for the first time a vast, complex web of intracluster starlight between the galaxies.

20 September 2005: With system and science verification complete, the Gemini Bench-mounted High-Resolution Spectrograph (bHROS) is available for science programs in 2006A. Proposals are due September 30, 2005. BHROS: a new and unique high-resolution optical spectrograph on Gemini South is the highest resolution optical (400-1000 nm) echelle spectrograph optimized for use on an 8-meter telescope. It achieves efficiencies of 13-18% (depending upon fiber mode with median seeing), with well-sampled spectra at a spectral resolution of R=150,000. Located within the thermally stable pier of the Gemini South telescope, bHROS is fiber-fed through the core of the telescope from the cassegrain focus. It is anticipated that bHROS will be well-suited for studies that include: High precision abundance analysis including determination of the 6Li/7Li isotopic ratio, abundances in ultra metal-poor stars, ISM, etc. Analysis of absorption line profiles High-precision radial velocity measurements (planet searches etc.)

15 September 2005: Fulfilling one of its central operational goals in a big way, the SOuthern Astrophysical Research Telescope (SOAR) on Cerro Pachón in Chile made the first observations of the glowing remains of the most distant explosion ever seen in the Universe. The international telescope then provided the first accurate measurement of just how incredibly far away this explosion appears to be.

6 September 2005: A unique wide-field view of the Orion Nebula in the mid-infrared, from Gemini South, is featured on the cover of the September 2005 NOAO/NSO Newsletter. This image reveals new details about the preferred locations and inferred lifespans of newborn planetary systems in the nebula. Other topics in the Newsletter include submissions to the NSF Senior Review, new partnership opportunities, and semester 2006A proposal information.