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Posts Tagged ‘solar’

New Exoplanet Too Big For Its Stars


An artist's impression of HATS-6. Credit ANU

An artist’s impression of HATS-6. Credit ANU

The Australian discovery of a strange exoplanet orbiting a small cool star 500 light years away is challenging ideas about how planets form.

“We have found a small star, with a giant planet the size of Jupiter, orbiting very closely,” said researcher George Zhou from the Research School of Astrophysics and Astronomy.

“It must have formed further out and migrated in, but our theories can’t explain how this happened.”

In the past two decades more than 1,800 extrasolar planets (or exoplanets) have been discovered outside our solar system orbiting around other stars.

The host star of the latest exoplanet, HATS-6, is classed as an M-dwarf, which is one of the most numerous types of stars in galaxy. Although they are common, M-dwarf stars are not well understood. Because they are cool they are also dim, making them difficult to study.

Link To Full Story

Astronomers Discover And “Weigh” Infant Solar System

December 8, 2012 Leave a comment

Astronomers have found the youngest still-forming solar system yet seen, an infant star surrounded by a swirling disk of dust and gas more than 450 light-years from Earth in the constellation Taurus.

The star currently has about one-fifth the mass of the Sun, but, the scientists say, will likely pull in material from its surroundings to eventually match the Sun’s mass. The disk surrounding the young star contains at least enough mass to make seven Jupiters, the largest planet in our Solar System.

“This very young object has all the elements of a solar system in the making,” said John Tobin, of the National Radio Astronomy Observatory. Tobin and his colleagues used the Submillimeter Array and the Combined Array for Millimeter-wave Astronomy to study the object, called L1527 IRS, residing in a stellar nursery called the Taurus Cloud.

Full Story: http://www.nrao.edu/pr/2012/youngsystem/

Hinode Mission to Capture Annular Solar Eclipse This Weekend


On May 20-21, 2012 an annular eclipse of the Sun will be visible from within a narrow corridor along Earth’s northern Hemisphere — beginning in eastern Asia, crossing the North Pacific Ocean, and ending in the western United States. A partial eclipse will be visible from a much larger region covering East Asia, North Pacific, North America and Greenland.

The joint JAXA/NASA Hinode mission will observe the eclipse and provide images and movies that will be available on the NASA website at http://www.nasa.gov/sunearth. Due to Hinode’s orbit around the Earth, Hinode will actually observe 4 separate partial eclipses.” Scientists often use an eclipse to help calibrate the instruments on the telescope by focusing in on the edge of the moon as it crosses the sun and measuring how sharp it appears in the images. An added bonus: Hinode’s X-ray Telescope will be able to provide images of the peaks and valleys of the lunar surface.

Full Story: http://www.nasa.gov/mission_pages/sunearth/news/eclipse-2012.html

Partial — and Annular — Eclipse of the Sun


People with clear skies across most of the U.S., Canada, and Mexico will experience a partial eclipse of the Sun late this Sunday afternoon (May 20, 2012). Only those near the Eastern Seaboard will miss out.

And, if you happen to be in a swath of land running from Northern California to Texas, you’ll also get a very special kind of partial eclipse: an annular eclipse, in which the rim of the Sun becomes a brilliant ring completely encircling the black silhouette of the Moon.

The Sun will be moving down the afternoon sky when a dark dent begins to intrude into one edge. The dent will deepen, eventually turning the Sun into a fat crescent — or, for western half of the continent, a thin crescent. The dent is the silhouette of the new Moon traveling along its monthly orbit around the Earth.

Most Westerners can see the entire eclipse from beginning to end before sunset. Farther east, sunset puts an end to the show while the eclipse is still in progress — affording weird and spectacular sunset scenes just above the west-northwest horizon. “This is going to be a great photo opportunity,” suggests Robert Naeye, editor in chief of Sky & Telescope magazine.

Full Story: http://www.skyandtelescope.com/about/pressreleases/Partial-151-and-Annular-151-Eclipse-of-the-Sun-to-Sweep-North-America-Sunday-May-20th-150977245.html

Solar ‘Climate Change’ Could Cause Rougher Space Weather

March 29, 2012 1 comment

Recent research shows that the space age has coincided with a period of unusually high solar activity, called a grand maximum. Isotopes in ice sheets and tree rings tell us that this grand solar maximum is one of 24 during the last 9300 years and suggest the high levels of solar magnetic field seen over the space age will reduce in future. This decline will cause a reduction in sunspot numbers and explosive solar events, but those events that do take place could be more damaging. Graduate student Luke Barnard of the University of Reading will present new results on ‘solar climate change’ in his paper at the National Astronomy Meeting in Manchester.

The level of radiation in the space environment is of great interest to scientists and engineers as it poses various threats to man-made systems including damage to electronics on satellites. It can also be a health hazard to astronauts and to a lesser extent the crew of high-altitude aircraft.

The main sources of radiation are galactic cosmic rays (GCRs), which are a continuous flow of highly energetic particles from outside our solar system and solar energetic particles (SEPs), which are accelerated to high energies in short bursts by explosive events on the sun. The amount of radiation in the near-Earth environment from these two sources is partly controlled in a complicated way by the strength of the Sun’s magnetic field.

There are theoretical predictions supported by observational evidence that a decline in the average strength of the Sun’s magnetic field would lead to an increase in the amount of GCRs reaching near-Earth space. Furthermore there are predictions that, although a decline in solar activity would mean less frequent bursts of SEPs, the bursts that do occur would be larger and more harmful.

Full Story: http://www.jodrellbank.manchester.ac.uk/meetings/nam2012/pressreleases/nam12.html

Strong Solar Activity Could Spark Auroras

September 7, 2011 Leave a comment

On Sept. 6th, active sunspot 1283 produced two major eruptions including an impulsive X2-class solar flare.  The blasts hurled a pair of coronal mass ejections (CMEs) toward Earth, which could spark geomagnetic activity when they arrive on Sept. 8-10.  High-latitude sky watchers should be alert for auroras in the nights ahead.  Checkhttp://spaceweather.com for images and updates.

Full Story: http://spaceweather.com/archive.php?view=1&day=07&month=09&year=2011

Ultrafast Substorm Auroras Explained

September 7, 2011 Leave a comment

From time to time, sudden releases of energy in Earth’s magnetosphere lead to major disturbances that result in bright auroral displays over the planet’s polar regions. These auroras are caused by a phenomenon known as a geomagnetic substorm. The precise cause of these substorms has been debated for decades, but new computer simulations, allied to analysis of data from ESA’s Cluster spacecraft, are now filling in many of the missing pieces in the puzzle.

Full Story: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=49107