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Antares is a Bug-Eyed Monster 700 Times Bigger Than Our Sun

Artist’s impression of Antares based on new observations by ESO’s VLTI. Credit: ESO/M. Kornmesser

From a “mere” 93 million miles away we’re able to view the surface of our home star the Sun very well with telescopes on Earth and in space…you can even observe large sunspots with your unaided eye (with proper protection, of course.) But the surface details of other stars tens, hundreds, or thousands of light-years away can’t be so easily resolved from Earth. The details are just too fine and get lost in the brilliance of the stars themselves.

But astronomers have now produced the best image yet of the surface of another star beyond our Solar System. Using the European Southern Observatory’s Very Large Telescope Interferometer, located on a high plateau in Chile’s Atacama Desert where the sky is some of the clearest and driest in the world, a team of scientists have mapped the movement of material in the atmosphere of Antares, a red supergiant star 700 times the size of our Sun that shines brightly in the heart of the constellation Scorpius. The observations enabled them to determine how material moves through Antares’ atmosphere and then construct an image of the star itself—the most accurate representation of another star besides the Sun.

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ESO Images NGC 1055, a Spiral Galaxy “On the Edge”

The spiral galaxy NGC 1055, imaged by ESO’s VLT (Credit: ESO)

The European Southern Observatory’s unimaginatively-named but incredibly powerful Very Large Telescope (VLT) located on a remote plateau high in the mountains of Chile’s Atacama Desert has captured a detailed view of NGC 1055, a spiral galaxy a little larger than our own located 55 million light-years away. On galactic scales this is relatively close by, and our edge-on perspective allows astronomers to determine the three-dimensional structure of this island of stars.

Spiral galaxies across the Universe can be found at all angles in relation to our viewpoint here on Earth. Some we see “face on,” which dramatically shows a spiral galaxy’s long, arcing arms and bright center but make it difficult to get a sense of true shape or variations in density. With NGC 1055 we see it “on edge,” without which it likely wouldn’t be known that it’s being tugged by one of its galactic neighbors.

Read the full story from ESO here: A Galaxy on the Edge

ESO Turns its ALMA Eyes on the Sun

ALMA image of the Sun captured in 1.25 millimeters. Credit: ALMA (ESO/NAOJ/NRAO)

The European Southern Observatory has begun imaging the Sun for the first  time, using its Atacama Large Millimeter/submillimeter Array (ALMA)—a suite of large dish-type telescopes located on a plateau 16,000 feet above sea level in the arid Chilean Andes. ALMA’s capabilities to observe in millimeter and submillimeter wavelengths allow imaging of the Sun’s dynamic chromosphere and the features within it, such as the center of a sunspot (above) that’s easily twice the size of Earth.

Read more here from ESO: ALMA Starts Observing the Sun

Ceres Displays Unexpected Flare-ups in Brightness to Ground-Based Survey

Bright reflective material in Ceres' Occator crater, imaged by NASA's Dawn spacecraft in Sept .2015. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Reflective material in Ceres’ 90-km-wide Occator crater, imaged by NASA’s Dawn spacecraft in Sept .2015. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Researchers using the High Accuracy Radial velocity Planet Searcher (HARPS) instrument on ESO’s 3.6-meter telescope at La Silla have detected “unexpected” changes in the brightness of Ceres during observations made in July and August of 2015. Variations in line with Ceres’ 9-hour rotational period were expected, but other fluctuations in brightness were also found that indicate albedo changes on a daily, diurnal basis.

Long story short: Ceres is slowly “blinking.”

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Only the Penitentes Shall Pass: Snow and Stars Near ESO’s ALMA

Icy penitentes march along the cold, dry ground on the Chajnantor Plateau near ALMA (ESO/Babak Tafreshi)

Icy penitentes march along the cold, dry ground on the Chajnantor Plateau near ALMA. Click for full version. (ESO/Babak Tafreshi)

I just had to share this beautiful image by ESO photo ambassador Babak Tafreshi; it shows a star-filled night sky above the Chajnantor Plateau on the border of Chile and Bolivia, the site of the Atacama Large Millimeter/submillimeter Array (ALMA) observatory. The site, chosen for its remote location and incredibly clear, dry sky, is one of the best on Earth for observing the most distant objects in the Universe.

The jagged snow features in the foreground are known as penitentes, for their resemblance to the conical hats of Spanish religious group members known as the Nazarenos. They are the result of Sun and wind erosion on high-altitude snow, although the exact process isn’t entirely known.

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