Space

Astronomers using the James Clerk Maxwell Telescope (JCMT) in Hawaii are making new discoveries about the origins of the planets, stars and galaxies with the start of a new survey to map the Universe.

The JCMT Legacy Survey, made up of 7 projects, makes use of two sophisticated new instruments - SCUBA-2 and HARP – which will allow the astronomers to detect and probe clouds of cold dust associated with the mysterious earliest phases of the formation of galaxies, stars and planets.

SCUBA-2 is a powerful camera capable of mapping regions of the sky by detecting the heat emitted by this extremely cold dust. It has recently been delivered to the JCMT and is under commission. When completed it will have the ability to pinpoint and image many hundreds of distant, dust enshrouded galaxies in a single night.


Venus Express looking back on Earth Credits: ESA/VIRTIS/INAF-IASF/Obs. de Paris-LESIA (Earth views: Solar System Simulator JPL-NASA)
This image composite shows the signatures of methane (CH4), carbon dioxide (CO2), ozone (O3) and nitrous oxide (N2O), minor species of the Earth’s atmosphere but powerful greenhouse gases, detected by the Visual and Infrared Thermal Imaging Spectrometer (VIRTIS) on board ESA’s Venus Express at infrared wavelengths, while the spacecraft was pointing Earth along its orbit around Venus.
Supercomputer simulations of dusty disks around sunlike stars show that planets even as small as Mars can create patterns that future telescopes might detect.

Much of the dust in our solar system forms inward of Jupiter's orbit, as comets crumble near the sun and asteroids of all sizes collide. The dust reflects sunlight and sometimes can be seen as a wedge-shaped sky glow -- called the zodiacal light -- before sunrise or after sunset.

The computer models account for the dust's response to gravity and other forces, including the star's light. Starlight exerts a slight drag on small particles that makes them lose orbital energy and drift closer to the star.


This week, Astronomy & Astrophysics is publishing new observations with AMBER/VLTI of the gas component in the vicinity of young stars. An international team of astronomers led by E. Tatulli (Grenoble, France) and S. Kraus (Bonn, Germany) [1] used the VLT near-infrared interferometer, coupled with spectroscopy, to probe the gaseous environment of Herbig Ae/Be stars. These are young stars of intermediate mass (approximately 2 to 10 solar masses), which are still contracting and often show strong line emissions.


Juno Spacecraft to Study Jupiter, we are informed by space.com. Don't people think before they give names, or choose songs? They select for weddings "I will always love you" by Whitney Houston, which is a song of irreversible parting, and I have even heard of a Church of England vicar choosing John Lennon's "Imagine there's no heaven" for something or other. I live on the eastern side of the Pond, which makes me a European, and the name of our continent is taken from that of Europa in Greek mythology.
Astronomers studying new images of a nearby galaxy cluster have found evidence that high-speed collisions between large elliptical galaxies may prevent new stars from forming, according to a paper in the November 2008 Astrophysical Journal Letters.

Led by Jeffrey Kenney, professor and chair of astronomy at Yale, the team saw a spectacular complex of warm gas filaments 400,000 light-years-long connecting the elliptical galaxy M86 and the spiral galaxy NGC 4438 in the Virgo galaxy cluster, providing striking evidence for a previously unsuspected high-speed collision between the galaxies. The view was constructed using the wide-field Mosaic imager on the National Science Foundation telescope at Kitt Peak National Observatory near Tucson, Arizona.


COROT has discovered a massive planet-sized object orbiting its parent star closely, unlike anything ever spotted before. It is so exotic, that scientists are unsure as to whether this oddity is actually a planet or a failed star.

The object, named COROT-exo-3b, is about the size of Jupiter, but packs more than 20 times the mass. It takes only 4 days and 6 hours to orbit its parent star, which is slightly larger than the Sun.

As a planet, COROT-exo-3b would be the most massive and the densest found to date - more than twice as dense as lead. Studying it will help them better understand how to categorise such objects. The mystery is how such a massive object formed so close to its parent.


For several decades, scientists have thought that the Solar System formed as a result of a shock wave from an exploding star — a supernova — that triggered the collapse of a dense, dusty gas cloud that contracted to form the Sun and the planets.

Models of this formation process have only worked under the simplifying assumption that the temperatures during the violent events remained constant but astrophysicists at the Carnegie Institution’s Department of Terrestrial Magnetism (DTM) say their new model says that a supernova could indeed have triggered the Solar System’s formation under the more likely conditions of rapid heating and cooling.


The “birth rate” for stars is certainly not easy to determine. Distances in the universe are far too great for astronomers to be able to count all the newly formed celestial bodies with the aid of a telescope so it is fortunate that emerging stars give themselves away by a characteristic signal known as “H-alpha” emissions.

The larger the number of stars being formed in a particular region of the firmament, the more H-alpha rays are emitted from that region.

More newborn stars are apparently emerging around the universe than previously assumed, say researchers at Bonn University who published a paper in “Nature” explaining that a systematic error in the method of estimation has resulted in a lower number.

The detailed study, called the ACS Nearby Galaxy Survey Treasury (ANGST) program, explored a region called the Local Volume, where galaxy distances range from 6.5 million light-years to 13 million light-years from Earth.

A typical galaxy contains billions of stars but looks smooth when viewed through a conventional telescope because the stars appear blurred together. In contrast, the galaxies observed in this new survey are close enough to Earth that the sharp view provided by Hubble's Advanced Camera for Surveys and Wide Field Planetary Camera 2 can resolve the brightness and colour of some individual stars. This allows scientists to determine the history of star formation within a galaxy and tease out subtle features in a galaxy's shape.