Tuesday, March 18, 2014

The California Nebula

Since it's pretty hard to top the recent discovery of inflation, I thought I'd just post a pretty picture for my final blog.


From Nasa's Astronomy Picture of the Day
I first saw this Nebula at the Palomar Visitor's Center.  It is named the California Nebula because it roughly resembles the shape of California (obviously) and it was discovered by E.E. Barnard; the guy Barnard's Star is named after.  According to Wikipedia, the light of this nebula is caused by Balmer beta emission lines from photons that hit the gas from a nearby O7-star that then releases the photon again at visible wavelengths.  It is very hard to see this with no filters so Wikipedia recommends that you use a Balmer beta filter if you wish to see this for yourself.

Monday, March 17, 2014

Direct Evidence for Inflation Detected


Alan Guth and Andrei Linde, developers of the idea of inflation.



The article that I posted yesterday was confirmed today by various scientists announcing their discoveries.  Using the BICEP2 telescope, these scientists have confirmed B-mode polarization patterns on the cosmic microwave background.  The implication of this discovery is that it gives a lot of information about when inflation happened, which one cosmologist approximated at .5 * 10^-37 seconds after the big bang.
Another implication is that this discovery directly proves that gravity is quantized, which sounds like a bigger deal to me but the article says that this is minor compared to the first implication.  This is also the first detection of Hawking's radiation as well as "the first detection of gravitational waves’ action on matter other than their source".  It seems like this announcement/discovery might be big enough to win a Nobel Prize.
B-modes
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Sunday, March 16, 2014

Possible Proof for Inflation to be Announced Tomorrow (Maybe)

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A press conference has been announced for Monday at the Havard Astrophysics center.  This website is speculating that they will announce some "Nobel Prize-worthy" evidence for the theory of cosmological inflation.  They speculate this because recently scientists at the South Pole telescope that detects microwaves might have detected some gravitational waves that originated from the big bang. 

The theory of inflation is way too complicated for me to understand but the gist of it seems to be that there are signals called B-modes which are emitted during the first 1/10000000000000000000000000000000000th (+- few orders of magnitude) of a second after the big bang.  Apparently researchers have found some signal with r = 0.2 (r is like the magnitude), which is more than they expected (r = 0.06).  They say that this bigger r value could affect galaxy formation more than previously expected.

On the article some scientist commented that if the press conference really does have evidence for inflation it could possibly lead to insight on quantum gravity.  While I have no idea what they're talking about, it seems to be a pretty important milestone in astrophysics, as well as physics in general.

Saturday, March 15, 2014

Observations Show that O Class Stars in Orion Prevent Planet Formation of Nearby Protostars

Researchers from Canada and the US have used the Atacama Large Millimeter Array to observe star formation in the Orion Nebula.  What they have found is that any young star that is within 0.1 light years of a O class star will have their surrounding dust be blown away by the photons emitted by the O class star.  This greatly hinders the formation of planets around these young stars, which means that there will be very few solar systems near O class stars.

 These stars from the Nebula form like the simulation showed in class when a large dust cloud reaches the Jeans mass.  The simulation showed that the largest stars formed first during the cloud collapse, so it makes sense that they would start disrupting the small stars before they had a chance to fully form their systems.  One of the Canadian scientists said that “Their energetic photons can quickly deplete a nearby protoplanetary disk by heating up its gas, breaking it up, and sweeping it away.”  I'm guessing this means that the photons from the O class star either impart some kinetic energy onto the gas and allow it to exceed the gravitational potential and escape, or it ionizes it and then emits neutrinos or something fancy.  Probably the former, but I wouldn't really know.

Overall I don't think these observations are really too groundbreaking, but merely a confirmation of something that makes a lot of sense theoretically. (Which is why they used "Death Star" in the title.)

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A picture of  two young stars and a O class star.  Apparently one of them is getting its dust blown away but I don't see it.

Wednesday, February 12, 2014

Gaia Satellite Will Take Five Months to Focus

The recently launched European telescope Gaia has just begun to focus its telescope, and will take up to five months to complete this before it can become fully operational.  Gaia is a telescope designed to survey the Milky Way using spectrophotometry and parallax measurements, it orbits the second Lagrange point of the Earth-Sun system.  As mentioned in lecture Gaia's instruments are significantly more precise than previous apertures so the data we get from this should be really useful.  Unfortunately the article mentions that it takes up to 3 years to process the data back and 5 years to collect... so we will have to wait until 2022 to get all the data!  While this is disappointing, I think it's great that Gaia will be able to collect data from up to a billion stars, as well as possible exoplanets that orbit those stars.  Maybe soon we can have those cool star wars holographic planetary maps.

Here's a pretty picture Gaia took.
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Tuesday, February 11, 2014

New Signs for Heavenly Objects Created

The Scottish Sensory Centre in cooperation with the Royal Observatory have created many new signs in British Sign Language for various planets and other astronomy related terms.



Here's the sign for supernova.  The similarity is uncanny.

Surprisingly, up until now, there were no signs for anything in space other than Earth and Sun, meaning that other planets or stars had to be spelled letter by letter.  This is a big step in the right direction, as the field of astronomy has long discriminated against mutes/deafs, what with their lack of means to communicate.  These new signs will help these forgotten souls finally rise up against the oppression.  Though if they do, they will find that they will be limited to the astronomy of our solar system.  The article reports that only 90 signs have been created, whereas there are billions of stars in the universe, meaning that at most only a few other stars have signs for them.  This is quite a big problem, since these mute/deaf astronomers will not be able to easily communicate about obscure stars with names like J05552+0724AP or PSR B1620-26.  Another problem is that these words only work in British Sign Language, which I'm pretty sure is not the most spoken (signed?) in the world.  I think we should have a sign language specifically for astronomy similar to how we have coordinate systems and date systems designed for it.  The system should be extremely convoluted and counter-intuitive to ensure that it fits in with the rest.

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Monday, February 10, 2014

Oldest Known Star Discovered (Again)

The supposed oldest star.  
Astronomers from Australian National University have discovered a star that has an age that is older than any other currently known star.  According to the article, this star is about 13.6 billion years old and offers insight into the chemistry of older stars.  The star was discovered by the university's own telescope and was confirmed with the Magellan Telescope in Chile. 

The way the astronomers date these stars is by looking at the iron content of the stars.  The more iron it has the older the star is.  This is probably because stars make light by fusion, and fusion of elements gradually increases until it stops at iron.  According to a quick Wikipedia search, iron is the heaviest stable element created by stellar nucleosynthesis, any heavier element created will quickly decay into iron.  If a star doesn't have much iron that means it hasn't been performing fusion for a long time (relatively) and thus must be pretty new.  The researchers mentioned in this article stated that the iron content of this star was found to be 60 times less than "any other star" which sounds pretty vague to me.  Personally I don't think this article is that interesting because I seem to have read this same article on many different occasions and they'll probably find another star that's older than this pretty soon.

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