My September cover story on ground-based telescopes and the accompanying blog post focused quite heavily on the constellation of observatories in Hawaii. However, other cutting-edge telescopes are racking up discoveries too.
European astronomers using the Very Large Telescope (VLT) in Chile have found new galaxies and intriguing features around stars in our own galaxy.
For example, one research team led by Nicholas Bouche of the Max Planck Institute for Extraterrestrial Physics in Germany discovered 14 previously unknown galaxies that had been obscured by the bright quasars behind them (from Earth’s viewpoint). To uncover the galaxies, the team used one of the four 8.2-m VLT telescopes equipped with SINFONI, a near-infrared spectrograph combined with adaptive optics to yield both sharp images and high-resolution spectra of their target objects.
A group headed by two astronomers from a Belgian university combined the near-infrared light from three of VLT’s telescopes through an interferometer called AMBER to discover a dusty disk around an aging star 2,600 light-years from Earth. The disk, hundreds of astronomical units across, also envelopes the companion star in the binary stellar system.
A third team led by astronomer Olivier Chesneau of France focused on the Ant Nebula, which is some 8,000 light-years away in the tiny southern constellation of Norma. The researchers combined light from two VLT units through a mid-infrared interferometer (MIDI) to find a slender disk of silicate dust in the middle of the nebula.
Another state-of-the-art observatory, the Large Binocular Telescope (LBT) in southeastern Arizona, is the instrument scientists used to find a galaxy’s odd cigar shape. A team from Germany, Italy and the University of Arizona employed the LBT’s short-wavelength camera and one of its twin 8.4-m mirrors to obtain a mosaic image of one of the 18 dwarf spheroidal galaxies that are satellites of our own Milky Way. The 19 astronomers found that this galaxy is flat, rather than round as most other galaxies of its type are.
According to LBT director Richard Green, the paper that the team is publishing in the October 10 issue of Astrophysical Review Letters is the first article in the astronomical literature that is based on LBT data. Undoubtedly, as the telescope is outfitted with its planned spectrographs and its second giant mirror and infrared camera come online, hundreds more papers will follow.
Finally, this just in: The international consortium planning the Giant Magellan Telescope (GMT) has chosen the Cerro Las Campanas site in Chile for the telescope. Las Campanas is already the home of the twin 6.5-m Magellan telescopes and two smaller instruments. As I reported in my September article, the first of the seven 8.4-m mirrors that will be combined to form the GMT is already being ground and polished at the Steward Observatory Mirror Lab, under the grandstands of the University of Arizona’s football stadium.
Photo of the LBT:
Photo of the four VLT observatories:
2007-10 October, Astronomy, Astrophysics