An age-defying star
For years, astronomers have puzzled over a massive star lodged deep in the Milky Way galaxy that appears to be extremely old and extremely young at the same time.
The age-defying star IRAS 19312+1950 stands out as extremely bright inside a large, chemically rich cloud of material, as shown in this image from NASA’s Spitzer Space Telescope. But a new study by a NASA-led team of researchers suggests the star – which is about 10 times as massive as our sun and emits about 20,000 times as much energy – is a newly forming protostar.
That was a big surprise because the region had not been considered a stellar nursery before. But the presence of a nearby interstellar bubble, which indicates the presence of a recently formed massive star, also supports this idea.
Hurricanes Madeline and Lester
The islands of Hawaii rarely take a direct hit from a hurricane. This week, two Pacific storms were lining up to change that.
The natural-color image above is a composite built from two overpasses by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite on 29 August. At the time, Hurricane Madeline and Hurricane Lester were hovering between category 3 and 4 storms. The bright streaks across the ocean surface (crossing Hawaii and Lester) are areas of sunglint, where sunlight reflected directly back at the VIIRS imager. At 11 am Hawaii Standard Time on Tuesday, Madeline was around 600 kilometres east-southeast of Hilo, Hawaii, and sustained wind speeds of 185 kilometres per hour. At the same time, Lester’s wind speed was 195 kilometres per hour and its position 2,100 kilometres east of Hilo.
At this time forecasters predicted that Hurricane Madeline would pass just south of Hawaii as a category 1 storm on Wednesday evening with Lester expected to approach Hawaii at hurricane force today and tomorrow, though models are so far predicting that it will pass just north of the islands.
According to several news reports, no hurricane has made landfall on the Big Island since recordkeeping started in 1949. Only 13 hurricanes have passed within 200 nautical miles of the island during that period.
This fiery illusion is actually a celestial feature named the Polaris Flare. This name is somewhat misleading; despite its moniker, the Polaris Flare is not a flare but a 10-light-year-wide bundle of dusty filaments in the constellation of Ursa Minor (The Little Bear), some 500 light-years away.
This image is not a true-colour view, nor is it an artistic impression. Rather it comprises observations from the Planck space observatory, which scanned and mapped the entire sky, including the plane of the Milky Way galaxy, looking for signs of ancient light (known as the cosmic microwave background) and cosmic dust emission between 2009 and 2013.
This dust emission allowed Planck to create this unique magnetic map of the sky. The relief lines laced across this image show the average direction of our galaxy’s magnetic field in the region containing the Polaris Flare.
Dust grains in and around the Milky Way are affected by and interlaced with the galaxy’s magnetic field, causing them to align preferentially in space.
Using a combination of Herschel space telescope observations and a computer simulation, scientists think that the Polaris Flare filaments could have been formed as slow shockwaves pushed through a dense interstellar cloud, an accumulation of cold cosmic dust and gas sitting between the stars of our galaxy.
These waves swept up the gas and dust in their path, sculpting the material into the snaking filaments we see.
Scientists can now directly probe a previously hard-to-see layer of chemistry thanks to a unique X-ray toolkit developed at the Department of Energy’s Lawrence Berkeley National Laboratory.
The X-ray tools and techniques could be extended, researchers say, to provide new insights about battery performance and corrosion, a wide range of chemical reactions, and even biological and environmental processes that rely on similar chemistry.
In a first-of-its-kind experiment using an X-ray source known as a synchrotron, researchers demonstrated a direct way to study the inner workings of an activity centre in chemistry known as an “electrochemical double layer”. It forms where liquids meets solids – where battery fluid (the electrolyte) meets an electrode, for instance (batteries have two electrodes: an anode and a cathode).
A key breakthrough enabling the latest experiment was tailoring “tender” X-rays – which have an energy range tuned in a middle ground between the typical high-energy (or “hard”) and low-energy (or “soft”) X-rays used in research – to focus on chemistry within the double layer of a sample electrochemical system. The study was published this week in Nature Communications.
The Great Elephant Census
The first-ever pan-African survey of savanna elephants, a $7-million, three-year Great Elephant Census, announced results this week.
The report published in the journal PeerJ confirms substantial declines in elephant numbers over just the past decade. The current rate of decline is 8% per year, primarily due to poaching.
The Pan-African survey shows the estimated savannah elephant population to be 352,271 within the 18 countries surveyed to-date, representing at least 93 percent of savannah elephants in these countries.
For savannah elephant populations in 15 of the countries examined, for which repeat counts were available, populations declined by 30% between 2007 and 2014. Some 84% of the population surveyed was sighted in legally protected areas.
But large numbers of carcasses were observed in many protected areas indicating that elephants are struggling both within and outside of parks. Experts say the ivory trade and poaching pose serious threats and there is now a risk that savannah elephants could disappear from parts of Africa.