Anuncios

7 Julio 2005: The Gemini community has embarked on a broad, multi-faceted search for planets around other stars. The prospect of answering the age-old question of how common solar systems like our own are in the universe captured the imaginations of astronomers who attended the June 2003 Aspen meeting, where new capabilities for the Gemini telescopes were imagined. In preparation for the next generation of planet-finding instruments, Gemini Observatory is actively looking for sub-stellar mass companions using the existing Adaptive Optics (AO) system Altair on Gemini North, and building the specialized near-infrared coronagraph (NICI) with its own AO system for Gemini South. Proposing for the NICI Planet Search Campaign We request that astronomers interested in participating in the NICI Planet Search Campaign send a short letter of interest to Joe Jensen, including the following details: name and institution; names and affiliations of other possible team members with whom you plan to or would …

5 Julio 2005: The blinking image above are two images of Tempel 1 about 20 minutes before and after the Deep Impact probe impacted the comet. These images of were taken using the Kitt Peak Visitor Center’s 20in Ritchey-Chretien telescope (RCOS) and an SBIG ST10XME CCD camera. A full size version of the above animation as well as a time-lapse animation are available on our Deep Impact page.

2 Julio 2005: The Gemini North telescope on Mauna Kea successfully captured the dramatic fireworks display produced by the collision of NASA's Deep Impact probe with Comet 9P/Tempel 1. Researchers in two control rooms on Hawaii’s Big Island (on Mauna Kea and in Hilo) were able to keep enough composure amid an almost giddy excitement to perform a preliminary analysis of the data. They concluded from the mid-infrared spectroscopic observations that there was strong evidence for silicates or rocky material exposed by the impact. Little doubt remains that the unprecedented quality of the Gemini data will keep astronomers busy for years. “The properties of the mid-infrared light were completely transformed after impact,” said David Harker of the University of San Diego, co-investigator for the research team. “In addition to brightening by a factor of about 4, the characteristics of the mid-infrared light was like a chameleon and within five minutes of the collision …

1 Julio 2005: How can you watch the planned first-of-its-kind collision between a comet and a spacecraft from Earth this weekend, even if your night skies don’t allow a direct view? The Visitor Center at Kitt Peak National Observatory plans to offer a live feed of the encounter between NASA’s Deep Impact mission and Comet Tempel 1 starting this Sunday night (local time), running about an hour before the planned 10:52 p.m. PDT impact though about 45 minutes afterward. The feed will consist of still images of the distant comet, and a frequently updated movie assembled from the individual frames, similar to the animation above (imaged on the night of June 14-15, 2005).

28 Junio 2005: Imaging by Gemini North's Michelle mid-infrared imager/spectrograph has allowed an international team of researchers to isolate and characterize the dusty remains of the supernova remnant SN 2002hh some 20 million light-years away. Led by UK astronomer Michael Barlow (University College London), the team imaged SN 2002hh in the relatively nearby galaxy NGC 6946 to study the dust expelled (and/or created) during the supernova explosion. Earlier Spitzer Space Telescope observations identified the dust excess from the supernova as part of the Survey for Evolution of Emission from Dust in Supernovae (SEEDS) project using Spitzer Infrared Nearby Galaxy Survey (SINGS) Legacy data set. However, due to a lack of spatial resolution, these observations failed to confirm the identity of Source 1 (see Figure 1) as the supernova. The new Gemini results provided an approximately ten-fold increase in resolution at 11.2 and 18.5 microns and were able to clearly isolate the supernova source …

16 Junio 2005: This image of a faint optical remnant of Gamma-Ray Burst (GRB) 050607 was obtained by James Rhoads (Space Telescope Science Institute) using the Mayall 4-meter telescope on Kitt Peak in the early morning hours of June 7, 2005. Rhoads suspended his science program and got “on source” on the GRB just 10 minutes after an alert was issued on the burst being detected by NASA’s Swift satellite.

15 Junio 2005: It's Tough Being Small(At Least in the Trapezium Region...) The observed distribution of stars as a function of mass has a well-established behavior known as the initial mass function (IMF). For normal stars the IMF says that the quantity of more massive stars is lower than the number of less massive counterparts. In other words, smaller stars are more numerous than bigger ones. How does the IMF behave at lower masses, e.g. subsolar masses or for brown dwarfs, or even planetary size bodies? Stars in the Orion Trapezium region are bombarded by intense ultraviolet radiation. Does such a hostile environment influence the IMF? We do not yet know the answers to these questions. To help provide answers, Gemini South Flamingos-I observations of the outer Trapezium region by Lucas et al. have probed the region to very faint levels in the infrared. These observations provide partial but very instructive clues. Lucas …

3 Junio 2005: The cover of the June, 2005 NOAO/NSO Newsletter features this false color image of the dynamic solar chromosphere, taken on 18 January 2005. Daily images like this one, made with the new SOLIS vector spectromagnetograph, have been obtained with various instruments on Kitt Peak for 31 years. The June Newsletter contains articles on a new roadmap for optical-infrared astronomy, related partnership opportunities at NOAO, and recent Gemini science instrument productivity.

1 Junio 2005: Dust Growth and Planet Formation Silicates found in the general interstellar medium or molecular clouds are exclusively amorphous, non-crystalline dust grains. However, both amorphous and crystalline dust grains are observed in more evolved stellar and planetary systems including those that, while still young, are in their later stages of formation. Thus, crystalline dust is present near T Tauri and Herbig Ae/Be stars, which are only a million or so years old, debris disks such as Beta Pic, which is 15-20 million years old, and our solar system, which is billions of years old (e.g., Comet C/1996 Q1). During the early formation and evolution of the dust in these systems, crystalline silicates form by a process that is still a mystery. The earlier we can look into the process of stellar evolution the better we can understand how the dust surrounding a young star is processed. Spectroscopy in the mid-infrared provides …

18 Mayo 2005: Curtains of gas and dust open dramatically to reveal the inner area of this starforming region. The unceremoniously named bright star SAO 152320 shines with intense light in the center of this field. Clouds of gas glow strongly and dust shrinks quickly under its radiative prowess. This vista lies some 4,000 light years away toward the constellation Monoceros. This is a portion of a much larger nebula called Gum 1.

6 Mayo 2005: The draft report of the O/IR Long Range Planning Committee is available for community review and input until May 15. See the O/IR Long Range Planning Committee web page for more information and to download a draft report.

28 Abril 2005: A joint Chile-United Kingdom team led by Simon Casassus (University of Chile) has used the NOAO-built Phoenix near-infrared spectrometer on Gemini South to obtain high-resolution spectra (R~75,000) of the [Al VI] 3.66-micron line region in the planetary nebula NGC 6302 (the Bug Nebula). By modeling the multi-component structure of the line, the team has been able to derive values for the electric quadrupole constant in the [Al VI] transition and measure a reliable isotopic ratio for aluminum. This is the first time such a constant in an atomic transition has been measured in any astrophysical object. The isotopic ratio of Aluminum (Al-26/Al-27) is of astrophysical interest because it is a signpost of recent nucleosynthesis. Al-27 is the stable isotope, while Al-26 is radioactive – with a half-life of 720,000 years. Because the ratio is poorly established, the origin of Al-26 is currently assigned to a range of astrophysical processes ranging …

16 Abril 2005: These images show two views of the active galaxy Centaurus A—in visible light from Cerro Tololo and in infrared light from two instruments aboard the NASA-JPL Spitzer Space Telescope. For more details, see the Image Gallery page.

12 Abril 2005: Recent spectroscopic studies of infrared light reflected from the surface of Sedna reveal that it is probably unlike Pluto and Charon since Sedna's surface does not display evidence for a large amount of either water or methane ice. Due to Sedna’s extreme distance from the Sun, the frigid surface has probably been untouched for millions of years by anything except cosmic rays and solar ultraviolet radiation. Gemini Observatory astronomer Chad Trujillo led an effort by the same California Institute of Technology research team responsible for Sedna's original discovery to obtain spectra of this distant planetoid using the Near Infrared Imager (NIRI) on Gemini North. Their aim was to better understand the surface of this distant world and how it has evolved since its formation. “It is likely that Sedna has experienced an extremely isolated life in the outskirts of our solar system,” said Trujillo. “Out there beyond what we used …

5 Abril 2005: The winter rains were plentiful in 2004-2005, giving rise to a beautiful display of wildflowers along the road to Kitt Peak. A number of telescopes are visible in the background of this image from March 2005, including the Mayall 4-meter telescope at the peak of the mountain.

28 Marzo 2005: Can galaxies observed at very high redshifts (at a time when the universe was a fraction of its current age) evolve to look like today's nearby galaxies simply by growing older? The answer is no according to an international team of scientists led by Inger Jørgenson (Gemini Observatory) who used GMOS on Gemini North, combined with HST imaging data to survey distant galaxies and chart their evolution. The team's results demonstrate that cluster galaxies closer to us are not aged versions of the kinds of early galaxies seen in distant clusters that existed when the universe was half its current age, about seven billion years ago. To evolve into galaxies like those we see in nearby clusters, these galaxies require more than just a single episode of star formation as current theories suggest — the distant early "progenitors" have to undergo a set of profound transformations that most likely include …

25 Marzo 2005: This open star cluster in the constellation Scorpius is set against the dramatic backdrop of the Milky Way. At 800-1000 light years away, M7's 80-odd stars are spread over some 20-25 light-years and are in excess of 200 million years old. This image of M7 was taken during the Advanced Observing Program.

11 Marzo 2005: How do massive stars form? The time scale for massive star formation is much shorter than for low-mass stars. During the birth process, a massive core will form first and begin evolving (converting hydrogen to helium) while the larger protostar is still accreting material. Like their lower-mass cousins, massive stellar objects are obscured by overlying envelopes of gas and dust during their formation which makes this stage of massive star formation a challenge to observe. Despite the difficulty of discerning the massive cores as they form, progress is being made on both theoretical and observational fronts. New, large-aperture ground-based telescopes (like Gemini) are providing capabilities which allow astronomers to look much farther away to study more of these rare massive stars in their formative stages and evolve in their birth environments. An international team including Robert Blum (CTIO), Peter Conti (JILA), Augusto Damineli, Elysandra Figuerêdo, and Cássio Barbosa (University of …

10 Marzo 2005: The March 2005 NOAO-NSO Newsletter contains articles on the pending NSF Senior Review, observing opportunities in Semester 2005B, the Gemini WFMOS instrument concept, and the WIYN One-Degree Imager.

1 Marzo 2005: How do you hide something as big and bright as a galaxy? You smother it in cosmic dust. Researchers used data from NASA's Spitzer Space Telescope and the NOAO Deep Wide-Field Survey to uncover a hidden population of monstrously bright galaxies approximately 11 billion light-years away.