Anuncios

28 Marzo 2006: Active observing ends on March 31, but dark-sky data will be accepted at the GLOBE at Night program for another week. NOAO is a major co-sponsor of this international public outreach activity, which has involved more than 12,200 people and 3,600 observations (and counting) from across the world.

21 Marzo 2006: Astronomers from the University of Hawaii's Institute for Astronomy (IfA) used Gemini North to make "crucial" observations of an object designated as Asteroid 118401. The Gemini imaging conclusively showed that the body is ejecting dust like a comet, according to an IfA press release based on a paper in the March 23rd issue of Science Express. University of Hawaii graduate student Henry Hsieh and Professor David Jewitt, who led the research, suggest that asteroids and comets are much more closely related than previously thought. The fact that there may be a class of icy bodies like comets that live primarily in the main asteroid belt strongly supports the idea that these objects could be a major source of Earth's present-day water. The Gemini observations were made using the GMOS imager on the night of November 26, 2005. The Gemini observations complement other observations made by the ESO 1.0-meter, UH 2.2-meter …

16 Marzo 2006: A team of astronomers led by Keivan Stassun of Vanderbilt University has used the Gemini South telescope and NOAO’s high-resolution infrared spectrograph Phoenix to uncover the dynamics of a pair of eclipsing brown dwarfs. The observations enabled the team to directly weigh and measure the brown dwarfs (often called “failed stars” for their intermediate mass between planets and stars). The Gemini data complemented data the team gathered from Kitt Peak and Cerro Tololo.

15 Marzo 2006: A U.S.-led team of astronomers, led by Keivan Stassun of Vanderbilt University, has used Gemini South's high-resolution infrared spectrograph PHOENIX to uncover the dynamics of the eclipsing brown dwarf pair 2MASS J0532184-0546085. The observations of the pair, in the Orion Nebula, complemented data from the 0.9-meter telescope at Kitt Peak and the 0.9-meter, 1.0-meter and 1.3-meter telescopes at the Cerro Tololo Inter-American Observatory. The findings show that the radii of the failed stars are quite large (as models predict), but that the least massive of the pair is hotter than the larger partner. The temperature observations are contrary to expectations. The Gemini data consists of a suite of high-resolution spectra made from eight observations between December 2002 and January 2003. This allowed the team to sample the velocities of the two objects throughout their entire orbital phase. This is the first direct, accurate measurements of the physical properties of young …

10 Marzo 2006: Gemini Observatory has worked since its inception to become a unique facility offering northern and southern sky coverage with telescopes fully optimized for mid-infrared (7-25 micron) observing. MICHELLE, the Gemini North mid-infrared imager and spectrometer, was first on the scene, initially operating only in a purely imaging mode for the scientific community in semester 2003B. During that same time, commissioning also began for T-ReCS (the Thermal-Region Camera and Spectrograph) at Gemini South. Since 2003B, Gemini staff members have made tremendous progress in enhancing and improving the mid-infrared performance of our telescopes and instruments. Now, more than ever, Gemini is poised to make great strides in understanding our mid-infrared universe. Gemini Mid-Infrared Capabilities are Better than Ever Among the improvements and enhancements, the 2006A semester marks the commissioning of the imaging polarimetry mode of MICHELLE. Our mid-infrared instruments are now fully operational for the upcoming 2006B semester and performing better than …

6 Marzo 2006: The new NOAO/NSO Newsletter includes articles on a variety of science results from the Magellanic Clouds, the commissioning of the NIFS spectrograph at Gemini North, the new NOAO NVO Portal, the SOAR telescope, and the future of imaging at WIYN.

2 Marzo 2006: A new era in astronomy education and outreach was ushered in with the opening of the ‘Imiloa Astronomy Center of Hawai‘i in Hilo, Hawai‘i. The unique 40,000-square-foot facility blends Hawaiian culture with the science of astronomy, using interactive exhibits, multi-media theaters and a state-of-the-art planetarium. The $28 million (U.S.) center was funded primarily through NASA and is located directly across from Gemini’s Hilo Base Facility on the University of Hawaii Hilo - Science and Technology Park. Gemini has been participating in the development of the center on many levels, from supplying content advisors to making the loan of our unused summit console for use in a Gemini-developed Virtual Observatory exhibit. Discussions are well underway to establish multiple partnerships with the center to leverage with Gemini’s local outreach and education programming. As part of the nine-day public preview events in mid-February, a fundraising dinner paid tribute to Senator Daniel K. Inouye …

24 Febrero 2006: The NOAO Data Products Program has unveiled a new Web-based tool to discover, access, and analyze astronomical imaging data from public archives. This effort is part of a larger program to provide the community with simple, consistent, astronomer-friendly interfaces to the tools and resources of the National Virtual Observatory (NVO).

16 Febrero 2006: Using Gemini observations of globular clusters in NGC 3379 (M105), a team led by PhD student Michael Pierce and Prof. Duncan Forbes of Swinburne University in Australia, have found evidence for normal quantities of dark matter in the galaxy’s dark halo. This is contrary to previous observations of planetary nebulae that indicated a paucity of dark matter in the galaxy. The observations of 22 globular clusters in the Leo Group elliptical galaxy were made using the Gemini Multi-Object Spectrograph (GMOS) on Gemini North in early 2003. The data were obtained in the GMOS multi-slit mode with exposures of 10 hours on-source at a spectral resolution of FWHM ~4Å over an effective wavelength range of 3800Å-6660Å. The final spectra have a signal-to-noise ratio of 18-58/Å at 5000 Å. The spectroscopic data allowed the team to derive ages, metallicities and α-element abundance ratios for the sample of globular clusters. All of the …

15 Febrero 2006: Dr. Douglas A. Simons has been appointed the next director of the Gemini Observatory effective June 1, 2006. The announcement was made today by Dr. William Smith, President of the Association of Universities for Research in Astronomy (AURA). AURA manages the Gemini Observatory under contract with the National Science Foundation on behalf of the partner countries United States, United Kingdom, Canada, Australia, Brazil and Argentina. “I am thrilled that Doug will continue to move Gemini forward to become the leading ground-based astronomical observatory with this appointment,” said AURA President Dr. Bill Smith. Dr. Michael Shull, Chair of the AURA Board, said “Doug’s knowledge and his leadership in the development of Gemini’s current and future instrumentation bode well for the observatory’s future. I am confident that the Gemini partners will benefit greatly from this appointment.” Dr. Simons is preceded by Professor Jean-René Roy who has been the acting director after Gemini’s …

8 Febrero 2006: This artist concept illustrates new Spitzer Space Telescope observations of an unusual class of interacting binary stars that emit excess amounts of infrared radiation, suggesting that these odd objects are surrounded by large disks of cool dust. The results were produced by one of six teams of professional astronomers and high school teachers participating in a unique program co-sponsored by the Spitzer Science Center and the National Optical Astronomy Observatory (NOAO). NOAO Press Release 06-04

3 Febrero 2006: The American Astronomical Society (AAS) has awarded its 2006 Education Prize to Dr. Sidney Wolff, an astronomer and former director of the National Optical Astronomy Observatory in Tucson, Arizona. The AAS Education Prize recognizes outstanding contributions to the education of the public, students and/or the next generation of professional astronomers. NOAO Press Release 06-05

1 Febrero 2006: An international team led by Kambiz Fathi of the Rochester Institute of Technology (RIT) and Thaisa Storchi-Bergmann of the Instituto de Fisica in Porto Alegre, Brazil recently mapped the gas velocity field and structure within the circumnuclear ring of the SBb LINER/Seyfert 1 galaxy NGC 1097 in unprecedented detail. Using the Gemini Multi-object Spectrograph (GMOS) integral field unit (IFU) on Gemini South, in conjunction with HST/ACS observations, the team found clear evidence of radial streaming motions associated with spiral structures that extend to within ~10 parsecs (~33 lightyears) of the unresolved (<3.5 parsecs (<11.4 lightyears)) nucleus. These motions have been interpreted as evidence that a large-scale "fueling chain" transports gas from the outer regions of the galaxy's nucleus directly into the nuclear starburst and supermassive black hole. Obtained on January 8, 2005, each of the Gemini two-dimensional spectroscopic observations covers a field of 5 x 7 arcseconds at a resolution …

26 Enero 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 Enero 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 Enero 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 Enero 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 Enero 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 Diciembre 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 Diciembre 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.