Announcements

9 June 2009: This issue includes an article by Andrei Tokovinin about speckle interferometry at the SOAR telescope. Short-exposure images of a 1.08" binary star were co-added with re-centering on the global centroid (left), or on the brightest pixel, selecting the sharpest 10 percent of images (right). This latter technique, dubbed “lucky imaging”, is gaining popularity .

8 June 2009: Using the Gemini Near-Infrared Spectrograph (GNIRS), astronomers have obtained an ultra-deep (~29 hour integration) near-infrared spectrum of a massive compact quiescent galaxy at a redshift of about 2.2 (when the universe was only about three billion years old). Understanding how a massive galaxy–especially this early in the history of the universe–can squelch star birth with such efficiency is a challenging problem for both observational and theoretical astrophysicists. The team, led by Mariska Kriek of Princeton University, used GNIRS on Gemini South to dissect the light of the galaxy, identified as 1255-0, in what is the deepest single-slit near infrared spectrum ever taken of a galaxy with a redshift greater than 2 (Figure 1). The spectrum, for the first time, shows absorption line features in this type of galaxy that allow for accurate redshift determination (Figure 2) and is providing insights into this unique category of galaxies that are very massive …

3 June 2009: Former NOAO Director Jeremy Mould (at left on Kitt Peak), professorial fellow at the University of Melbourne School of Physics, Australia joins Wendy Freedman (top right), director of the Observatories of the Carnegie Institution of Washington in Pasadena, California, USA and Robert Kennicutt (bottom right), director of the Institute of Astronomy at the University of Cambridge in England as the recipients of the 2009 Cosmology Prize of the Peter and Patricia Gruber Foundation.

21 May 2009: Set among the beauty of Kyoto University, Japan about 200 users and staff of the Gemini and Subaru observatories and the National Gemini Offices participated in the first joint Gemini and Subaru science conference from May 18-22, 2009. The 5-day meeting provided an opportunity for participants to share a wide range of research topics spanning studies of our solar system and exoplanets to cosmology and the high redshift universe. Users also shared innovative observing techniques, unique collaborations and looked toward the future of both observatories and how they can work together to best serve our users and remain competitive. In particular, methods and procedures for coordinating the use, planning, and construction of future instruments were discussed. The goals of the conference were to promote a mutual understanding of both communities and to highlight the international nature of modern astronomy. These goals were clearly achieved. Key scientific topics of the conference: …

18 May 2009: The Orion Nebula seen with the infrared eyes of the WIYN High Resolution Infrared Camera (WHIRC) in the emission lines of HeI (1083 nm; blue), FeII (1644 nm; green), and H2 (2122 nm; red).

6 May 2009: Winter on Mauna Kea usually consists of fairly short periods of very poor weather (including snowstorms) among longer periods of good conditions brought on by the passages of fronts coming from the northwest. At times a Kona low-pressure system develops causing conditions at Mauna Kea to deteriorate. However, a passing front will usually clear out the low-pressure system and return good astronomical observing conditions on Mauna Kea. This past winter has, to a large extent, lacked fronts that clear out the low-pressure systems. The result has been a large fraction of observing time lost to weather, and very poor conditions when observing was possible. The long-term weather loss for Gemini North for the 18 northern hemisphere “winter” weeks December 24, 2008 through April 28 is about 35%. Figure 1 shows the range and average cumulative weather loss typical for Gemini North for these 18 weeks (orange shaded area of figure). …

21 April 2009: This Mayall 4-m image of the Medusa Nebula was released during the "Around the World in 80 Telescopes" webcast held from April 3-4, 2009.

14 April 2009: An international team led by Ben Burningham (University of Hertfordshire) has discovered a brown dwarf that will likely set the record as the coolest body ever detected outside our solar system. The object, named Wolf 940b, and its central star, a red dwarf named Wolf 940, lies in the constellation Aquarius at a distance of 40 light-years from Earth. Wolf 940b orbits its star at a distance of around 440 astronomical units, more than ten times farther out than Neptune orbits the Sun. At this distance, it takes wolf 940b around 18,000 years to complete a single orbit. The mass of Wolf 940b is probably between 20 and 30 times that of Jupiter. This places it directly in the regime of “brown dwarfs” – objects that are too large to be considered planets but are too small (and cool) to be classified as stars. With a surface temperature of approximately …

6 April 2009: A team led by Ph.D. student Luan Ghezzi of the Observatorio Nacional Rio de Janeiro, Brazil, has established that there is no detectable amount of Lithium-6 in five stars that host extrasolar planets. The team used the bench High-Resolution Optical Spectrograph (bHROS) on Gemini South to make the observations. One of the interesting properties of stars known to host giant planets is that these stars are systematically metal-rich (by about ~0.2 dex) relative to field dwarfs not known to harbor giant planets. Two hypotheses have been proposed to account for this excess of elements heavier than hydrogen or helium: primordial enrichment or pollution. The first process indicates that the probability of forming giant planets is a steeply rising function of the intrinsic metallicity of the gas which gave rise to the birth of the star and its planets. The pollution scenario, on the other hand, proposes that during the inward …

6 April 2009: This Blanco 4-m image of NGC 6520, and nearby dustcloud Barnard 86, was released during the "Around the World in 80 Telescopes" webcast held from April 3-4, 2009.

30 March 2009: Gemini is pleased to announce the 2009 Gemini Users Meeting that will be held at Kyoto University, Kyoto Japan, in conjunction with the Joint Subaru/Gemini Science Conference. The main goal of the Users Meeting is to provide an opportunity for Gemini's community to provide feedback to the Observatory on both short-term operational issues and long-term strategic issues such as future instrumentation. 2009 Gemini Users Meeting Agenda 9:30 Welcome (Packham) I Operations Status and Reports - Chair: TBD 9:35- Queue completion rates and Operational Efficiency (Jørgensen - 30+5) 10:10 - Dataflow Project (Labrie - 15+5) 10:30 - Gemini Publications: Productivity and Impact (Crabtree - 15+5) 10:50 -Break (20) II Instrumentation / Adaptive Optics Updates - Chair: TBD 11:10 - Altair/LGS (Christou - 10+5) 11:25 - MCAO (Rigaut - (15+5) 11:45 - NICI (TBD - 10+5) 12:00 - GNIRS (Geballe - 10+5) 12:15 - FLAMINGOS-2 (Gomez - 15+5) 12:35-GMOS CCDs (TBD - …

17 March 2009: In a paper published in the March 19, 2009 issue of Science Express, Justyn Maund and Stephen Smartt present data from the Gemini Observatory and Hubble Space Telescope (HST) that confirms the disappearance of the progenitors of two Type II supernovae (SNe). The only other supernova progenitor of this sort known to have definitively disappeared was SN 1987A in the Large Magellanic Cloud, part of our Local Group of Galaxies. Because the identity of the stars found in pre-explosion images has now been confirmed, this work provides the important “nail in the coffin” that the now missing Red Supergiants were the progenitors. The two supernovae, denoted 1993J and 2003gd, both had confirmed pre-existing progenitors identified from archival data which allowed the researchers to compare pre-supernova identification of the progenitor star with post-supernova observations. Maund and Smartt used a technique where images were taken after SN 2003gd had faded away, and …

13 March 2009: The “GLOBE at Night” citizen-science campaign has reached 10,000 contributed measurements during its 13 day campaign this year in March!

9 March 2009: Finding a needle in a haystack might be easy compared to finding two very similar black holes closely orbiting each other in a distant galaxy. Astronomers from the National Optical Astronomy Observatory (NOAO) in Tucson have found what looks like two massive black holes orbiting each other in the center of one galaxy.

3 March 2009: This issue highlights science being done with telescopes available through the broader "System" of telescope access, and includes articles on new and upcoming instruments for SOAR in Chile and WIYN on Kitt Peak.

25 February 2009: Certainly one of the strangest objects in our Milky Way galaxy has been hiding as a variable X-ray source called SAX J1808.4-3658. This X-ray binary has been known to contain an accretion-powered millisecond pulsar located at a distance of 3,500 parsec (~11,500 light-years). It was also the first identified millisecond pulsar system among X-ray binaries. Recent observations with GMOS-S (Gemini Multi-Object Spectrograph – at Gemini South) have revealed a large periodic modulation of its quiescent optical emission. The observations show a light curve with a remarkably regular sinusoidal shape of ~0.4 magnitude in amplitude in r’ band (Figure 1). Conducted by the Canadian-Dutch team led by Zhongxiang Wang (McGill University), the new observations indicate that the light curve modulation is caused by irradiation of the companion star to the pulsar, and not by activity in the accretion disk. The pair is strange because it is comprised of an unusual couple: …

24 February 2009: This image of R136, the massive star cluster at the center of the 30 Doradus nebula in the Large Magellanic Cloud was taken on Spartan’s second commissioning run on the SOAR telescope.

20 February 2009: NOAO astronomer and U.S. IYA Project Director Stephen Pompea shows off the “Galileoscope” student telescope kit in Paris.

11 February 2009: In the context of the currently favored cosmological Λ-Cold Dark Matter model of the universe, the formation and evolution of galaxies remains a major unsolved problem. In particular, the detailed evolution of the bulge and disk components of spiral galaxies is not well represented in current simulations. The data–model discrepancies do not necessarily reflect a failure in the ΛCDM model, but may indicate physical regimes and processes that are either poorly understood or difficult to implement in large simulations. Given the significant challenges faced by current galaxy formation models, guidance towards a true understanding of disk galaxies must come from an observational perspective such as the one described here using the Gemini Multi-Object Spectrograph. A very useful probe in discerning between formation scenarios is a detailed breakdown of the age, metallicity (Z), and kinematic properties of the stellar population (SP) content comprising bulges of all types. Information about both light- …

29 January 2009: NOAO astronomer and U.S. IYA Project Director Stephen Pompea shows off the “Galileoscope” student telescope kit at IYA opening ceremonies at UNESCO Headquarters in Paris.