The Young Astronomers
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NASA’s Chandra X-ray Observatory (along with optical data provided by the ESO and infra-red data supplied by the Spitzer space telescope) has produced a truly amazing image of the star cluster NGC 1929 located within the nebula N44.
N44 and NGC 1929 Credit:X-ray: NASA/CXC/U.Mich./S.Oey, IR: NASA/JPL, Optical: ESO/WFI/2.2-m
The nebula and its star cluster are located in the Milky Way’s largest satellite galaxy – the Large Magellanic Cloud (LMC) – at a distance of 160,000 light years from Earth - 940.6 quadrillion miles.
The star cluster is composed of primarily newborn stars that have only recently been forged from the surrounding material.A great number of these are many times the mass of the sun and produce a precipitous amount of hard radiation and vicious solar winds, before burning out in (on the time scales of the universe) sort order as supernovae generating incredible outpourings of energy.
These shockwaves along with the continual bombardment from radiation and particle stream gouges out massive ‘bubbles’ in the surrounding nebula. The x-ray data provided by Chandra (shown in blue) shows the regions of the nebula that are at the highest temperatures – the areas under the heaviest onslaught of radiation or reeling from one or more shockwaves . The cooler gas and dust as detected by Spitzer is displayed in red with the yellow regions show where the radiation is actually causing the surrounding material to glow in the visible range (this data was collected by the ESO’s Max-Planck telescope).
Astronomers have been having a problem with N44 and other similar ‘superbubbles’ in the LMC for sometime now – they are producing too many x-rays.
Before anyone panics, this is not a medical problem (we aren’t all going to suffer radiation poisoning thanks to a few over-active nebulae in another galaxy), it only refers to the measurements pointing to such nebulae producing more x-rays than could be explained using current knowledge – our knowledge of such objects must be incomplete.
A previous study had suggested that the shockwaves of supernovae impacting the bubble’s walls along with the evaporation of hot material from the sides of the bubble could perhaps explain this anomaly. This set of observations at least doesn’t find any supporting evidence for these ideas though it has been the first time that the observations have been sensitive to distinguish between these and other possibilities so progress is being made.
You can read more here
In around eight hours at 06:31 am, (I’m not counting, honest) the Mars Curiosity Rover will begin her descent into the Martian atmosphere and, if all of the many stages of descent and landing go perfectly, begin her mission.
The mission itself is to find out if the past – or present – environment on mars was suitable for microbial life to inhabit the soil. The mission will last as long as Curiosity does, her plutonium power source will give her enough power to be our interplanetary geologist for at least 687 days; a Martian year.
As of an hour ago Curiosity was just 142,783 km away from Mars, less than a third of the distance Earth is from the Moon. If you’d like to know plenty more snippets like this I suggest following @MSL_101 on twitter or the official NASA account, @MarsCuriosity.
I also had to share this brilliant NASA Jet Propulsion Lab video describing the challenges faced during descent. Unsurprisingly it’s described as ‘the seven minutes of terror’:
You can find a good summary of the mission here!
NASA’s Chandra X-ray observatory has produced a spectacular image of the spiral galaxy M83:
Chandra’s view of M87 and SN 1957D Credit: NASA/CXC/STScI/K.Long et al.
The primary target of the image wasn’t the galaxy itself but a supernova remnant within – the remains of SN 1957D
This supernova remnant had previously been detected in both visible and the infra-red though had previously eluded detection in x-rays (Chandra’s first attempt to capture the object in 2000-2001 met with disappointment). This image is the end result of nearly eight and a half days of data collection using Chandra, a truly marathon effort (the observation was completed in stages during 2010 and 2011 rather than in one massive event).
The image show a wide range of X-rays, with low energy rays displayed in red, medium energy in green and those with the highest energies displayed here in blues.
The Chandra team has also produced an annotated version of the image showing the location of the remnant and you can see this below:
Credit: X-ray: NASA/CXC/STScI/K.Long et al., Optical: NASA/STScI
The type of X-ray emission detected from the remnant strongly suggests that it contains a rapidly spinning neutron star – a pulsar. This potentially makes it the youngest pulsar ever observed, positively confirmed as one just 55 years after it was formed (discounting the time it has taken the light to reach us here on Earth). It is potentially the youngest ever observed as there is another contender – SN 1979C – though as of yet astronomers aren’t quite sure if it is indeed a pulsar or a black hole.
M83 itself sits about 15 million light years from us in the direction of the constellation Hydra. It is one of the brightest galaxies visible from Earth and can be observed through binoculars.
M83 Credit: ESO/IDA/Danish 1.5 m/R. Gendler, S. Guisard and C. Thöne
You can read more here
A new image from NASA’s WISE mission has been released showing the beauty of a region of the Orion Molecular Cloud Complex known as the Flame Nebula.
The Flame Nebula as seen by WISE Credit: NASA/JPL-Caltech
The nebula is glowing with infra-red light thanks in no small part to a star 20 times the mass of our own sun that is blanketed with a dense surround of dust and gas. The star churns out vast quantities of energy that warm the dust causing it in turn to give of the infra-red light that has been collected to form this image.
The surrounding dust is so dense it causes the star to appear an amazing 4 billion times fainter to the naked eye than if it was free in space. Without this obscuring dust that star would appear as bright as the stars of Orion’s belt itself.
The smaller bright region about half way down the image is the nebula NGC 2023 – A reflection nebula surrounding a bright B class star
NGC 2023 Credit: Adam Block/NOAO/AURA/NSF
Slightly below and to the right of NGC 2023, the tuft of protruding material is actually the famous Horsehead Nebula:
The Horsehead Nebula Credit: ESO
The final remarkable feature in this image is the bright red crescent in its lower right portion. This is the bowshock – a wave of material deflected out of the way of a moving star – of the star Sigma Orionis.
You can read more about this image here
We are becoming accustomed to a steady stream of new planets and solar systems being discovered by one of the many planet hunting projects that are currently in operation. Whilst all are interesting, some are particularly unusual and intriguing. One such system is Kepler 36.
Located 1530 light years away in the direction of the constellation Cygnus – The Swan – Kepler 36 is a yellow subgiant (that is a star somewhere between a main sequence star like our own sun and a true giant like Arcturus) of spectral class G1IV. It is ever so slightly more massive than the sun though has a much larger radius (1.63 times as large to be exact).
What is truly interesting however is not the star itself, but the two planets that have been detected in its orbit.
Kepler 36b (from here on simply 36b) orbits at a distance of less than 11 million miles. 36b is classed as a ‘terrestrial super-earth’ being half as large as the Earth again and having 4.5 times the Earth’s mass. It whizzes round its parent star once every 14 days (for comparison the innermost planet in our solar system Mercury orbits once every 88 days). Its partner Kepler 36c (from here on 36c) orbits at a distance of 12 million miles and has been described as a ’mini-Neptune’. c is roughly 8 times the mass of the Earth but the majority of this mass is spread out over a large region producing a planet who’s average density is just 0.86g/cm3 – less than the density of water.
The two planets are particularly unusual as they orbit their star very close together (this is in relative terms of course!) with their close orbits producing very close conjunctions (occurrences when the location of two or more stellar objects in their orbits brings them very close together) on average once every 97 days. At such a conjunction the two are separated by a just 5 Earth-Moon distances (just over 1.2 million miles).
Such events would produce exceptional sights with the planets dominating the other’s sky. There are physical consequences for such close encounters however, the strong gravitational forces acting between the two would cause significant gravitational tides. Such tides are likely to produce significant geological activity on the rocky 36b, potentially including volcanoes and lava flows. The close pairings have also likely stripped most if not all of 36b’s atmosphere leaving a barren, hot rock inhospitable to any life as we know it.
Kepler 36b and 36c Credit: CfA
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