Announcements

24 June 2003: A sixth magnitude globular cluster in the constellation Canes Venatici, this ball of 500,000 stars is approximately 160 light years across and 100,000 light years from Earth. The image is a combination of a B-band image and a Z-band image (Z is approximately from 8500 to 9500 A) taken at the WIYN 3.5-meter telescope with the WIYN Tip-Tilt Module (WTTM).

17 June 2003: On the second night of its first commissioning run on the Gemini South Telescope, the facility mid-infrared imager/spectrograph T-ReCS was used to obtain an image of Mars using a spectral filter centered at a wavelength of 12.8 microns. The image was made at 7h27m UTC on 2003 June 4. Bright areas are relatively warm, and dark areas may be cooler. In the "raw" image on the left, the bright region corresponds to the sub-solar point; there is a brightness gradient roughly symmetrical about the sub-solar point, actually skewed a bit towards mid-afternoon due to thermal inertia. The middle image shows a specially processed (unsharp-mask) version of the T-ReCS data that accentuates finer details. The right image is a composite of visible data from the Mars Global Surveyor (National Geographic Society, MOLA Science Team, MSSS, JPL, NASA) taken from the Mars Now webpage and shows Mars at approximately the same orientation …

27 May 2003: This star cluster in Perseus is the home of at least seven extremely large dusty disks around young stars where newborn planets could be forming. These disks were detected in infrared images using the FLAMINGOS instrument at Kitt Peak.

27 May 2003: Issue #26 (June 2003) of the Gemini Newsletter has been printed and is now being shipped to all partner offices.

12 May 2003: In 1943 the American astronomer Carl K. Seyfert reported that a small percentage of galaxies have very bright nuclei that are the source of broad optical emission lines seen in their spectra. Nearly stellar in appearance, these nuclei are responsible for the emission of strong lines produced by atoms in a wide range of ionization stages. Today these objects are known as Seyfert Galaxies and the spiral galaxy NGC 4151 is a good example of this type of object. Seyfert Galaxies belong to a broader class of objects called Active Galactic Nuclei (AGN) that are characterized by energetic emission across the entire electromagnetic spectrum, from the radio to X-rays. The power source for an AGN is thought to be a central supermassive black hole where energy is generated by matter accreting onto the black hole itself and onto its surrounding accretion disk. James Radomski of the University of Florida and …

9 May 2003: This composite picture is a seamless blend of ultra-sharp NASA Hubble Space Telescope images combined with the wide view of the Mosaic Camera on the WIYN 0.9-meter telescope at Kitt Peak National Observatory near Tucson, Arizona.

29 April 2003: Some highly magnetized neutron stars (magnetars) are known to periodically flare up and emit large quantities of X-rays. These bursts are thought to be caused when the solid surface of the neutron star cracks, triggering "star quakes." The energy is transferred to the magnetic field and out into the hot gas that is trapped near the magnetar. One such X-ray burst was recently observed from a type of magnetar that had not been seen to burst before, conclusively linking two types of neutron stars that had previously been thought to be different. Gemini's Near-Infrared Imager, NIRI, was trained on the magnetar 1E 2259+586 shortly after X-ray bursts were detected in June of 2002. The magnetar was observed to be more than 3 times brighter in the infrared than it is in its quiescent phase. NIRI re-imaged the magnetar a week later and confirmed that it was fading, showing that the …

17 April 2003: A compact spiral galaxy in the constellation Coma Berenices, this image of NGC4274 comes from the public Kitt Peak Advanced Observing Program.

15 April 2003: Binary stars evolve in interesting ways. The more massive star in a pair evolves faster and may explode as a supernova if its original mass is greater than about 7 times the mass of our Sun. The result is that either a neutron star or a black hole is found orbiting the lower-mass companion star - as is the case with A0620-00. This system consists of an X-ray novae star, powered by the sporadic accretion material from its companion, a K5 main-sequence star. The relative faintness of the secondary star has allowed the measurement of the radial velocity of both the accretion disk around the black hole and the companion star. The black hole mass is still not well known; the most recent estimate is 11.0+/-1.9Msun (solar mass). 2668-2678, November 2001). A more robust measure is that the mass has to be greater than 2.72+/-0.06Msun. Soft X-ray transients (SXT), also …

2 April 2003: Saturn's moon Titan, the second largest moon in the solar system, is surrounded by a thick atmosphere of molecular nitrogen with a few percentage points of methane. This atmosphere appears to host a variety of meteorological features that show a seasonal cycle. Titan's apparent angular diameter from Earth (~0.8 arcseconds) can be resolved from the ground only with advanced techniques like adaptive optics. The opacity of Titan's stratospheric haze decreases sharply with wavelengths across the visible into the infrared. There are narrow spectral windows in the near infrared between the methane bands through which astronomers can probe Titan's surface and lower atmosphere. Henry Roe (University of California, Berkeley) and his collaborators used adaptive optics on the Gemini North and Keck II telescopes to study the tropospheric haze and the discrete clouds of Titan, and to probe its surface (Figure 1). Their observations have revealed that the southern hemisphere shows more …

1 April 2003: This wide-field image of the Crescent Nebula (NGC6888) was taken at the National Science Foundation's 0.9-meter telescope on Kitt Peak with the NOAO Mosaic CCD camera.

25 March 2003: Over 5 days in late February/early March, staff members completely moved into the new Gemini South Southern Base Facility in La Serena, Chile. The 15,000-plus-square-foot facility features 30 offices, a 42-seat lecture hall, 2 instrument labs, 2 conference rooms and the Gemini South sea-level control room. Approximately 40 staff members currently occupy the facility.

17 March 2003: This image of M5 comes from the public Kitt Peak Advanced Observing Program.

7 March 2003: Located in the constellation Coma Berenices, M100 (also known as NGC4321) is one of the brighter galaxies in the Virgo Cluster. The presence of many young stars give the arms of this spiral galaxy a blue appearance. This image was taken December 20, 2002 at the WIYN 0.9-meter telescope on Kitt Peak.

26 February 2003: The Gemini Near-infrared Imager (NIRI) has been working reliably and delivering excellent images at wavelengths between 1 and 5 microns. In one NIRI program, very sharp images (0.35 arcsecs FWHM without adaptive optics correction) of 11 different sub-regions of the nearby spiral galaxy M33 were collected over a period of two nights in September 2002. The infrared NIRI images probe through the intervening dust in M33 and allow us a clear view of the many evolved giant stars in this galaxy. In the inset infrared (IR) image, 22,000 individual giant stars were detected and measured. The image on the left shows what this same field looks like at visible wavelengths with a seeing of 0.75 arcsecs (FWHM). The dust seen in the optical image all but disappears in the NIRI IR image (a composite of 1.6 and 2.1 micron images). Taking a census of the stars in other galaxies is …

17 February 2003: This month’s Hubble Heritage image of the Dumbbell Nebula is superimposed onto a WIYN image of M27, highlighting the differences in the field of view of the two telescopes. The Heritage site features several other supplemental ground-based images from WIYN and the Mayall 4-meter telescope.

12 February 2003: The tightest orbiting brown dwarf companion ever seen has been discovered orbiting the low mass star LHS 2397a, using adaptive optics on Gemini North. The faint companion completes its orbit around the parent star at a distance of about 3 astronomical units (AUs) every 20 years. The images above show LHS 2397a in four bandpasses. The first image on the left is an optical image in the I Band obtained with the Hubble Space Telescope (HST) on April 12, 1997. The brown dwarf is seen as the very faint object at nine o'clock and is very difficult to detect in this unenhanced image. The next three images were obtained using adaptive optics in the near infrared (J, H and K' bands) on Gemini North five years later (February 7, 2002). The Gemini images use a Fourier filter to enhance the visibility of the companion, hence the presence of the companion …

29 January 2003: This unusual image was created from five frames imaged with filters covering a narrow range of wavelengths. The color changes across filaments are indicative of physical changes in the bright emission nebula.

28 January 2003: Today, in a live videoconference connecting Hawai`i with Chile, the six teachers selected to participate in the Gemini Observatory StarTeachers Exchange Program were officially announced. During the event, the 3 teachers from each location met and shared some of their ideas for the exchange using the same advanced high-speed internet videoconferencing technology that they will use to present lessons to their students back home during the exchange. The Hawai`i teachers are scheduled to visit their colleagues in Chile for two weeks in March and the Chilean teachers will make a reciprocal visit to Hawai`i in October 2003. The three Big Island StarTeachers selected are Kristen Luning, Chairperson of the Math Department at Keaau High School; Alicia Hui, a fifth grade teacher at Haili Christian School; and Christine Copes, a math and Resource Teacher at Waiakea Elementary School. The three Chilean teachers are Carmen Luz Briones, Viviana Calderon and Jenny Opazo. …

21 January 2003: Violent bush fires ravaging Canberra destroyed most of the facilities at the Stromlo Observatory. Fortunately there were no additional human injuries or casualties. More details on the loss of Gemini's Near-Infrared Integral Field Spectrograph can be found at the links below. Astronomy projects in ruins as observatory obliterated Aussie Fires Destroy Mount Stromlo Observatory Australian fire felt in Hilo Gemini Near-Infrared Integral-Field Spectrograph (NIFS): Destroyed by Bushfire January 2003 Historic Australian observatory gutted The Mount Stromlo Fires: A Major Heritage Loss For Australian Astronomy Mount Stromlo Observatory Destroyed by Fire Pictures of the aftermath of the fire of Saturday, 18 January 2003, at Mount Stromlo Observatory