NASA'S HUBBLE REVEALS ROGUE PLANETARY ORBIT FOR FOMALHAUT
WASHINGTON -- Newly released NASA Hubble Space Telescope images of a
vast debris disk encircling the nearby star Fomalhaut and a
mysterious planet circling it may provide forensic evidence of a
titanic planetary disruption in the system.
Astronomers are surprised to find the debris belt is wider than
previously known, spanning a section of space from 14 to nearly 20
billion miles from the star. Even more surprisingly, the latest
Hubble images have allowed a team of astronomers to calculate the
planet follows an unusual elliptical orbit that carries it on a
potentially destructive path through the vast dust ring.
The planet, called Fomalhaut b, swings as close to its star as 4.6
billion miles, and the outermost point of its orbit is 27 billion
miles away from the star. The orbit was recalculated from the newest
Hubble observation made last year.
"We are shocked. This is not what we expected," said Paul Kalas of the
University of California at Berkeley and the SETI Institute in
Mountain View, Calif.
The Fomalhaut team led by Kalas considers this circumstantial evidence
there may be other planet-like bodies in the system that
gravitationally disturbed Fomalhaut b to place it in such a highly
eccentric orbit. The team presented its finding Tuesday at the 221st
meeting of the American Astronomical Society in Long Beach, Calif.
Among several scenarios to explain Fomalhaut b's 2,000-year-long orbit
is the hypothesis that an as yet undiscovered planet gravitationally
ejected Fomalhaut b from a position closer to the star, and sent it
flying in an orbit that extends beyond the dust belt.
"Hot Jupiters get tossed through scattering events, where one planet
goes in and one gets thrown out," said co-investigator Mark Clampin
of NASA's Goddard Space Flight Center in Greenbelt, Md. "This could
be the planet that gets thrown out."
Hubble also found the dust and ice belt encircling the star Fomalhaut
has an apparent gap slicing across the belt. This might have been
carved by another undetected planet. Hubble's exquisite view of the
dust belt shows irregularities that strongly motivate a search for
other planets in the system.
If its orbit lies in the same plane with the dust belt, then Fomalhaut
b will intersect the belt around 2032 on the outbound leg of its
orbit. During the crossing, icy and rocky debris in the belt could
crash into the planet's atmosphere and create the type of cosmic
fireworks seen when Comet Shoemaker-Levy 9 crashed into Jupiter. Most
of the fireworks from collisions will be seen in infrared light.
However, if Fomalhaut b is not co-planar with the belt, the only
thing to be seen will be a gradual dimming of Fomalhaut b as it
travels farther from the star.
Kalas hypothesized that Fomalhaut b's extreme orbit is a major clue in
explaining why the planet is unusually bright in visible light, but
very dim in infrared light. It is possible the planet's optical
brightness originates from a ring or shroud of dust around the
planet, which reflects starlight. The dust would be rapidly produced
by satellites orbiting the planet, which would suffer extreme erosion
by impacts and gravitational stirring when Fomalhaut b enters into
the planetary system after a millennium of deep freeze beyond the
main belt. An analogy can be found by looking at Saturn, which has a
tenuous, but very large dust ring produced when meteoroids hit the
outer moon Phoebe.
The team has also considered a different scenario where a hypothetical
second dwarf planet suffered a catastrophic collision with Fomalhaut
b. The collision scenario would explain why the star Fomalhaut has a
narrow outer belt linked to an extreme planet. But in this case the
belt is young, less than 10,000 years old, and it is difficult to
produce energetic collisions far from the star in such young systems.
Fomalhaut is a special system because it looks like scientists may
have a snapshot of what our solar system was doing 4 billion years
ago. The planetary architecture is being redrawn, the comet belts are
evolving, and planets may be gaining and losing their moons.
Astronomers will continue monitoring Fomalhaut b for decades to come
because they may have a chance to observe a planet entering an icy
debris belt that is like the Kuiper Belt at the fringe of our own
solar system.
Wednesday, January 9, 2013
Star Vega: This second brightest star in northern night skies too has an asteroid belt around it
2013
WASHINGTON -- Astronomers have discovered what appears to be a large
asteroid belt around the star Vega, the second brightest star in
northern night skies. The scientists used data from NASA's Spitzer
Space Telescope and the European Space Agency's (ESA) Herschel Space
Observatory, in which NASA plays an important role.
The discovery of an asteroid belt-like band of debris around Vega
makes the star similar to another observed star called Fomalhaut. The
data are consistent with both stars having inner, warm belts and
outer, cool belts separated by a gap. This architecture is similar to
the asteroid and Kuiper belts in our own solar system.
What is maintaining the gap between the warm and cool belts around
Vega and Fomalhaut? The results strongly suggest the answer is
multiple planets. Our solar system's asteroid belt, which lies
between Mars and Jupiter, is maintained by the gravity of the
terrestrial planets and the giant planets, and the outer Kuiper belt
is sculpted by the giant planets.
"Our findings echo recent results showing multiple-planet systems are
common beyond our sun," said Kate Su, an astronomer at the Steward
Observatory at the University of Arizona. Su presented the results
Tuesday at the American Astronomical Society meeting in Long Beach,
Calif., and is lead author of a paper on the findings accepted for
publication in the Astrophysical Journal.
Vega and Fomalhaut are similar in other ways. Both are about twice the
mass of our sun and burn a hotter, bluer color in visible light. Both
stars are relatively nearby at about 25 light-years away. The stars
are thought to be around 400 million years old, but Vega could be
closer to its 600 millionth birthday. Fomalhaut has a single
candidate planet orbiting it, Fomalhaut b, which orbits at the inner
edge of its cometary belt.
The Herschel and Spitzer telescopes detected infrared light emitted by
warm and cold dust in discrete bands around Vega and Fomalhaut,
discovering the new asteroid belt around Vega and confirming the
existence of the other belts around both stars. Comets and the
collisions of rocky chunks replenish the dust in these bands. The
inner belts in these systems cannot be seen in visible light because
the glare of their stars outshines them.
Both the inner and outer belts contain far more material than our own
asteroid and Kuiper belts. The reason is twofold: the star systems
are far younger than our own, which has had hundreds of millions more
years to clean house, and the systems likely formed from an initially
more massive cloud of gas and dust than our solar system.
The gap between the inner and outer debris belts for Vega and
Fomalhaut also proportionally corresponds to the distance between our
sun's asteroid and Kuiper belts. This distance works out to a ratio
of about 1:10, with the outer belt 10 times farther away from its
host star than the inner belt. As for the large gap between the two
belts, it is likely there are several undetected planets,
Jupiter-sized or smaller, creating a dust-free zone between the two
belts. A good comparison star system is HR 8799, which has four known
planets that sweep up the space between two similar disks of debris.
"Overall, the large gap between the warm and the cold belts is a
signpost that points to multiple planets likely orbiting around Vega
and Fomalhaut," said Su.
If unseen planets do in fact orbit Vega and Fomalhaut, these bodies
will not likely stay hidden.
"Upcoming new facilities such as NASA's James Webb Space Telescope
should be able to find the planets," said paper co-author Karl
Stapelfeldt, chief of the Exoplanets and Stellar Astrophysics
Laboratory at NASA's Goddard Space Flight Center in Greenbelt, Md.
Saturday, January 5, 2013
All about the Red Planet Mars: Yet another meteorite contains water
2013
WASHINGTON -- NASA-funded researchers analyzing a small meteorite that
may be the first discovered from the Martian surface or crust have
found it contains 10 times more water than other Martian meteorites
from unknown origins.
This new class of meteorite was found in 2011 in the Sahara Desert.
Designated Northwest Africa (NWA) 7034, and nicknamed "Black Beauty,"
it weighs approximately 11 ounces (320 grams). After more than a year
of intensive study, a team of U.S. scientists determined the
meteorite formed 2.1 billion years ago during the beginning of the
most recent geologic period on Mars, known as the Amazonian.
"The age of NWA 7034 is important because it is significantly older
than most other Martian meteorites," said Mitch Schulte, program
scientist for the Mars Exploration Program at NASA Headquarters in
Washington. "We now have insight into a piece of Mars' history at a
critical time in its evolution."
The meteorite is an excellent match for surface rocks and outcrops
NASA has studied remotely via Mars rovers and Mars-orbiting
satellites. NWA 7034's composition is different from any previously
studied Martian meteorite. The research is published in Thursday's
edition of Science Express.
"The contents of this meteorite may challenge many long held notions
about Martian geology," said John Grunsfeld, associate administrator
for NASA's Science Mission Directorate in Washington. "These findings
also present an important reference frame for the Curiosity rover as
it searches for reduced organics in the minerals exposed in the
bedrock of Gale Crater."
NWA 7034 is made of cemented fragments of basalt, rock that forms from
rapidly cooled lava. The fragments are primarily feldspar and
pyroxene, most likely from volcanic activity. This unusual
meteorite's chemistry matches that of the Martian crust as measured
by NASA's Mars Exploration Rovers and Mars Odyssey Orbiter.
"This Martian meteorite has everything in its composition that you'd
want in order to further our understanding of the Red Planet," said
Carl Agee, leader of the analysis team and director and curator at
the University of New Mexico's Institute of Meteoritics in
Albuquerque. "This unique meteorite tells us what volcanism was like
on Mars 2 billion years ago. It also gives us a glimpse of ancient
surface and environmental conditions on Mars that no other meteorite
has ever offered."
The research team included groups at the University of California at
San Diego and the Carnegie Institution in Washington. Experiments
were conducted to analyze mineral and chemical composition, age, and
water content.
Researchers theorize the large amount of water contained in NWA 7034
may have originated from interaction of the rocks with water present
in Mars' crust. The meteorite also has a different mixture of oxygen
isotopes than has been found in other Martian meteorites, which could
have resulted from interaction with the Martian atmosphere.
Most Martian meteorites are divided into three rock types, named after
three meteorites; Shergotty, Nakhla, and Chassigny. These "SNC"
meteorites currently number about 110. Their point of origin on Mars
is not known and recent data from lander and orbiter missions suggest
they are a mismatch for the Martian crust. Although NWA 7034 has
similarities to the SNC meteorites, including the presence of
macromolecular organic carbon, this new meteorite has many unique
characteristics.
"The texture of the NWA meteorite is not like any of the SNC
meteorites," said co-author Andrew Steele, who led the carbon
analysis at the Carnegie Institution's Geophysical Laboratory. "This
is an exciting measurement in Mars and planetary science. We now have
more context than ever before to understanding where they may come
from."
The research was funded by NASA's Cosmochemistry Program and
Astrobiology Institute, part of the Planetary Science Division in the
Science Mission Directorate at NASA Headquarters. The research also
was supported by the New Mexico Space Grant Consortium in Las Cruces,
and the National Science Foundation in Arlington, Va.
Tuesday, January 1, 2013
Dog flu and bird flu similarities: The first systematic surveillance of H3N2 canine influenza virus (CIV) in various dog populations in southern China revealed that the viruses were similar to recently isolated avian-origin strains in dogs and cats from Korea and elsewhere in China
2012
The first systematic surveillance of H3N2 canine influenza virus (CIV) in various dog populations in southern China revealed that the viruses were similar to recently isolated avian-origin strains in dogs and cats from Korea and elsewhere in China.
The researchers based their findings on canine nasal samples taken from dog farms in Guangzhou and Shenzen and from pet dogs.
They reported their findings in the Dec 20 issue of Infection, Genetics and Evolution. Serologic surveillance revealed that the infection rates for avian-origin H3N2 in farmed and pet dogs were 12.22% and 5.3%, respectively.
The authors suggested that the virus probably spread via close contact between infected dogs in different dog populations.
The group warned that virus circulation in a densely populated area with heavy animal trade poses a risk for pets and provides an environment for mutations and reassortment that could lead to new virus strains and possible threats to public health.
Sirturo (bedaquiline) for multidrug-resistant tuberculosis: The US Food and Drug Administration (FDA) approves Sirturo (bedaquiline), the first drug developed specifically to treat multidrug-resistant tuberculosis (MDR-TB), saying it must be used in combination with other TB medications
FDA approves first med for multidrug-resistant TB
Robert Roos 
News Editor
News EditorThe drug, developed by Jannsen Therapeutics, Titusville, N.J., inhibits an enzyme that Mycobacterium tuberculosis uses to replicate and spread, the FDA said in a news release. Janssen officials said it is the first TB drug in 40 years that has a new mechanism of action.
MDR-TB strains are those that resist isoniazid and rifampin, the two drugs most commonly used to treat TB patients, the FDA noted.
"Multi-drug resistant tuberculosis poses a serious health threat throughout the world, and Sirturo provides much-needed treatment for patients who don't have other therapeutic options available," said Edward Cox, MD, MPH, in the FDA release. He is director of the Office of Antimicrobial Products in the FDA's Center for Drug Evaluation and Research.
But he warned that the drug carries significant risks, including heart arrhythmias, and therefore must be used carefully and limited to patients who lack other treatment options.
About 310,000 cases of MDR-TB were identified among reported pulmonary TB patients in 2011, according to the World Health Organization. In the United States, MDR-TB is considered an orphan disease, with 98 patients reported in 2011, according to a Janssen press release.
The FDA said it endorsed Sirturo under its accelerated approval program, which allows the agency to approve a drug on the basis of a demonstrated effect on a surrogate end point that is reasonably likely to predict a clinical benefit to patients. The program speeds the availability of new drugs while requiring companies to conduct more studies of their benefits and safety.
The FDA also granted Sirturo fast-track status, priority review, and orphan-product designation. The drug showed the potential to fill an unmet medical need, has the potential to provide safe and effective treatment where no other satisfactory therapy exists, and is intended to treat a rare disease, the agency said.
Sirturo's safety and effectiveness were established in two phase 2 clinical trials involving 440 patients, the FDA reported. The surrogate end point used in the studies was the time it took for patients' sputum to be clear of M tuberculosis (sputum culture conversion).
Patients in the first trial were randomly assigned to be treated either with Sirturo plus other TB drugs or with a placebo and other TB drugs. Patients in the Sirturo group had a median sputum conversion time of 83 days, versus 125 days for the placebo group.
In the second trial, which is ongoing, all patients received Sirturo plus other TB drugs. Results so far have shown a median time to sputum conversion of 57 days, supporting the efficacy findings of the first trial, the FDA said.
Common side effects identified in the clinical trials include nausea, joint pain, and headache, the agency noted.
The FDA and Janssen said Sirturo carries a boxed warning that the drug can affect the heart's electrical activity by prolonging the QT interval, which could lead to an abnormal and potentially fatal heart rhythm.
The warning also says that in the placebo-controlled trial, 9 of 79 patients (11.4%) in the treatment group died, compared with 2 of 81 (2.5%) in the placebo group.
"Five of the deaths in the Sirturo group and all of the deaths in the placebo arm seemed to be related to tuberculosis, but no consistent reason for the deaths in the remaining Sirturo-treated patients could be identified," the FDA said.
The Janssen statement said Sirturo inhibits mycobacterial adenosine 5'-triphosphate, an essential enzyme for generating energy in M tuberculosis. The drug was discovered more than a decade ago, said Paul Stoffels, MD, chief scientific officer and worldwide pharmaceuticals chairman at Johnson & Johnson, Janssen's parent company.
ICRISAT’s genebank, one of the world’s largest public-funded genebanks, preserves seeds of more than 120,000 accessions of pearl millet, sorghum, chickpea, pigeonpea, groundnut and small millets (finger millet, foxtail millet, barnyard millet, kodo millet, and little millet)
Olympic medalist lauds ICRISAT’s gene conservation efforts in the fight against hunger and poverty
Hyderabad: Dec 30: “ICRISAT’s plant genetic conservation initiatives illustrate the value and use of crop biodiversity in the fight against hunger and poverty, and its impact on the livelihoods of millions of smallholder farmers in the dryland tropics,” said India’s ace badminton player and Olympic bronze medalist Ms Saina Nehwal.
During her visit to the Hyderabad-based International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) today, Ms Nehwal described her experience touring the Institute’s facilities, particularly its RS Paroda Genebank, as delightful and an eye-opener.
“Nature has truly blessed us with a rich genetic diversity, which is unique and important in sustaining life in this planet. This visit gave me a better understanding of the importance of plant genetic conservation in sustaining and using genetic diversity for global food security,” Ms Newhal added.
“ICRISAT’s RS Paroda Genebank is a treasure trove of genes useful to crop improvement for sustainable food production and improved livelihoods, particularly in marginal environments, and genes that can provide climate resilience to future crop varieties through increased drought, heat and salinity tolerance, and pest and disease resistance, said ICRISAT Director General William D. Dar.
ICRISAT has been conducting research-for-development initiatives with partners globally for the past 40 years to increase agricultural production in the semi-arid regions of Asia and sub-Saharan Africa.
ICRISAT’s genebank, one of the world’s largest public-funded genebanks, preserves seeds of more than 120,000 accessions of pearl millet, sorghum, chickpea, pigeonpea, groundnut and small millets (finger millet, foxtail millet, barnyard millet, kodo millet, and little millet), that are kept as in-trust collections on behalf of the Food and Agriculture Organization (FAO) of the United Nations (UN), for the benefit of the present and future generations.
It has also distributed more than 1.4 million seed samples to 146 countries, restored about 55,000 germplasm lines to 9 countries, and released 830 cultivars in 79 countries from its germplasm and breeding materials.
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