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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.

23 Febrero 2005: About 500 million years ago a spheroidal galaxy captured a small gas-rich galaxy in a merger that led to a burst of star formation. Using the integral field unit (IFU) on GMOS-South, Mark Swinbank (University of Durham, UK), led an international research team to explore this merging system that is still in the process of digesting the gas and stellar components of the two original galaxies. The galaxy SDSS J101345.39+011613.06, known simply as “E+A” (geminiann05002a), has a redshift of 0.1055, corresponding to a distance of roughly 490 Mpc (or 1.6 billion light-years). This hybrid galaxy has a disturbed morphology and shows signatures of both old low-mass stars (spectral type K) and massive but short-lived stars (spectral type A) distributed throughout. However, the youngest and most massive ones—the OB-type stars—are missing, which indicates that the last star-forming event in E+A took place a few hundred million years ago. Recent spectroscopy conducted …

10 Febrero 2005: Visible light images from NOAO telescopes (left) have been used by scientists from the Spitzer Science Center to help them better understand dozens of massive embryonic stars in the Trifid Nebula (M20), which were discovered in images from two instruments aboard the Spitzer Space Telescope (right).

31 Enero 2005: NOAO Astronomer Steve Ridgway is part of a team that used the CHARA array on Mount Wilson to make detailed measurements of the physical properties of Regulus, the brightest star in Leo. They found that Regulus’ frenetic spin gives the star a grossly bulging mid-section; its equatorial diameter is one-third larger than its north-south diameter. The star’s axis of rotation happens to point in the same direction as its motion through the galaxy—meaning Regulus zips along like an enormous, spinning bullet.

27 Enero 2005: A long-standing problem in understanding the evolution of stars has been determining the nature of the stellar progenitors for white dwarf stars. In particular, astronomers want to know how a rather massive star (up to seven times the mass of the Sun) can lose enough mass to become a white dwarf. Key questions include: Which main-sequence stars eventually end their life as white dwarfs? How much mass do they lose in late evolutionary stages? What process allows this to occur? Some answers can be found in the 100th published paper based upon Gemini data. A Canadian, U.S., and Australian team led by Ph. D. student Jason Singh Kalirai of the University of British Columbia selected 24 individual white dwarfs[1] in the field of the rich open star cluster NGC 2099 (M37). This initial identification was made from analysis of deep wide-field imaging using the Canada-France-Hawaii Telescope. By following up on …

11 Enero 2005: A current rendering of the 8.4-meter Large Synoptic Survey Telescope (LSST) which will use a special three-mirror design, creating an exceptionally wide field of view. The LSST Corporation has awarded a $2.3 million contract to the University of Arizona Steward Observatory Mirror Lab to purchase the glass and begin engineering work for the 8.4-meter diameter main mirror that will enable the LSST to survey the visible sky in only three nights. LSST press release

2 Enero 2005: Like the annual New Year’s fireworks display, astronomers at Gemini Observatory are ushering in 2005 with a striking image that dazzles the eye with stellar pyrotechnics. In this new image, the face-on spiral galaxy NGC 6946 is ablaze with colorful outbursts fueled by the births and deaths of multitudes of brilliant, massive stars.

24 Diciembre 2004: The staff of the National Optical Astronomy Observatory wishes you all the best this holiday season.

20 Diciembre 2004: Using adaptive optics on the Gemini North and Keck II telescopes on Mauna Kea, Hawai’i, a U.S. team has discovered a new phenomenon in the atmosphere of Saturn’s largest moon Titan. Unlike previous observations showing storms at the south pole, these new images reveal atmospheric disturbances at Titan’s temperate mid latitudes—about halfway between the equator and the poles. Read the Gemini Press Release.

13 Diciembre 2004: Discovered just this past summer, Comet Machholz continues to brighten toward being visible with the unaided eye in both the northern and southern hemispheres. This image was taken at the Kitt Peak Visitor Center Observatory on December 11, 2004.

7 Diciembre 2004: Gemini staff have successfully repeated the coating of a 8-meter primary mirror with protected silver during a 9-day shutdown period. This is the second successful silver coating of a Gemini primary mirror and was applied on Thanksgiving Day in a 7-hour process interrupted by an intense hail storm at midday. This is the second time a Gemini primary mirror has been coated with protected silver (Gemini South was coated in May 2004) and now all key optical surfaces (primary, secondary and science fold mirrors) are coated. This is a milestone in front surface mirror coating technology. The result is a dramatic reduction in the thermal emissivity of the telescope systems—down to an unprecedented level of about 2% or lower. Following the successful coating, team members cheered as reflectivity values were announced and they realized that the coating was successful. The application of protected silver coatings on both Gemini telescopes is …

2 Diciembre 2004: This image of the massive N11 complex is featured on the cover of the December 2004 NOAO Newsletter. Numerous star forming regions and shells blown out by supernovae and strong stellar winds can be seen. The data used to create the image were taken with the University of Michigan Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory near La Serena, Chile, as part of the Magellanic Clouds Emission Line Survey (MCELS).

30 Noviembre 2004: Kevin Luhman (Harvard-Smithsonian Center for Astrophysics), Dawn Peterson (University of Rochester) and S. T. Megeath (also CfA) used the newly commissioned Gemini Near Infrared Spectrograph (GNIRS) on Gemini South to determine the nature of the low-mass object OTS 44. The observations of the faint infrared object confirmed that it is a very low-mass, newborn brown dwarf and the lowest mass brown dwarf found to date in the Chamaeleon I cloud complex. The Chamaeleon I cloud complex is a nearby star-forming region located about 170 parsecs (554 light-years) away from us toward the constellation of Chamaeleon. From the strength of the water vapor (steam) absorption band around 1.5 and 2 microns, and in comparison to other low-mass stellar objects, the team determined OTS 44 to be of very late spectral type M9.5 (geminiann04018a). They estimate its effective temperature at 2300 K. Using the flux in the H band and the object’s …

4 Noviembre 2004: Using archived science verification data from the Hokupa'a/QUIRC Adaptive Optics system on Gemini North, a French/US team of astronomers led by Jean-Pierre Maillard of the Institut d’Astrophysique de Paris has confirmed the physical association of a cluster of massive stars in the infrared source IRS 13 near the center of the Milky Way galaxy. The team also used data from Hubble Space Telescope, the Chandra X-Ray Observatory, the Canada-France-Hawai’i Telescope (CFHT), and the Very Large Array to complement the Gemini data. The Gemini observations consisted of deconvolved H and Kp band images that identified the existence of two formerly undetected sources within the eastern component of IRS 13 (called IRS 13E). When the Gemini data were used in conjunction with longer and shorter wavelength observations, it was possible to conclude that these sources were massive stars comparable to the stars of the same type which are exceptionally concentrated in the …

27 Octubre 2004: Closest Known Brown Dwarf has a Companion. While searching for planet-sized bodies that might accompany the nearby star system Epsilon Indi, astronomers using the Gemini South telescope in Chile made a related but unexpected detection. Widely observed by telescopes on the ground and in space, Epsilon Indi was known to host an orbiting companion, called Epsilon Indi B, which was discovered last year and is the nearest known specimen of a brown dwarf. Brown dwarfs are very small, cool stars thirty to forty times more massive than Jupiter but of similar size. Despite all the observing, it took the combination of Gemini's powerful infrared capabilities and the extremely sensitive spectrograph/imager called PHOENIX (without adaptive optics) to reveal the more elusive body. "Epsilon Indi Ba is the closest confirmed brown dwarf to our solar system," says Dr. Gordon Walker (University of British Columbia, Vancouver, Canada), who led the research team that …

22 Octubre 2004: The third data release (DR3) from the NOAO Deep Wide-Field Survey (NDWFS) is now available. This release includes all the Mosaic-1 optical and ONIS K-band imaging of the 9.3 square degree Boötes survey field. Catalogs of objects detected in the images are also provided. The images can also be obtained via the NOAO Science Archive.

19 Octubre 2004: Eight meter-class telescopes such as Gemini, the Very Large Telescope (VLT), Subaru and Keck have opened up the high-redshift universe for detailed study. Several galaxies out to redshifts of z ~ 6.6 are now known and Gemini has played a significant role in their discovery: "Searching for the end of the cosmic dark ages with GMOS", "Gemini Probes Galaxy Evolution a Billion Years After the Big Bang". Finding even more distant galaxies is particularly important to our understanding of the formation of the very first stellar objects in the history of the universe, and of the ensuing reionization of the intergalactic medium. This epoch of “first light” at redshifts between ~7-15 marked the end of the early universe’s dark ages – a time when the universe was filled with mostly neutral hydrogen. Recently, Pelló et al. (Astronomy and Astrophysics, vol. 416, p. 35, 2004) identified a possible highly magnified object …

9 Octubre 2004: A stunning image released today by the Gemini Observatory captures the graceful interactions of a galactic ballet, on a stage some 300 million light years away, that might better be described as a contortionist's dance. The galaxies, members of a famous troupe called Stephan's Quintet, are literally tearing each other apart. Their shapes are warped by gravitational interactions occurring over millions of years. Sweeping arches of gas and dust trace the interactions and possible ghost-like passage of the galaxies through one another. The ongoing dance deformed their structures while spawning a prolific fireworks display of star formation fueled by clouds of hydrogen gas that were shocked into clumps to form stellar nurseries. This unprecedented image of the cluster provides a unique combination of sensitivity, high resolution and field of view. "It doesn't take long to reach an incredible depth when you have an 8-meter mirror collecting light under excellent conditions," …

5 Octubre 2004: Astronomers including Steve Howell of NOAO-WIYN have used the Gemini North and Keck II telescopes to peer inside a violent binary star system to find that one of the interacting stars has lost so much mass to its partner that it has regressed to a strange, inert body resembling no known star type. Gemini Press Release

27 Septiembre 2004: Mira stars, red giant variables that have been studied for 400 years, are generally half as large in diameter as had been believed, thanks to an opaque shell of water vapor and other molecules that surrounds them. A team including Steve Ridgway of NOAO used the IOTA interferometer on Mount Hopkins, AZ, to make this discovery. Read more in the Astronomy and Astrophysics press release, Forseeing the Sun’s Fate.