Some of you may have read in the newspapers about a scientific study of the Lithium abundance in stars and if they have planets or not. It basically says that if the star has a low abundance of Lithium it can indicate that there are planets around it. Our Sun is famous for having a low abundance of Lithium and we know that we have planets here, but we don't know why we have that low abundance. In media you can therefor read about this study as a big breakthrough in finding planets around stars. They even claim that we now know where to look to find planets.
BBC news - Lithium clue for planet-hunters
Ok, I'm gonna be the bad guy here. The study seem kinda well made but what they actually say is that they've found out that solar type stars with massive planets close to them seem to have a low abundance of Lithium. First of all: solar type stars. In the universe we have alot of different type of stars. Some of them we call solar type because they have about the same temperature at the surface as our own Sun. There can be other criterions as well, but all in all they are kinda similar to our Sun. What I can see they've just looked at solar type stars, so all the other types we can't say much about from this study.
The other thing is that when astronomers find planets around other stars they are mostly very massive with an orbit very close to the star. We need better instruments and methods to find less massive objects further away from the star. Well, we have managed to find those objects but it's very rare cases. So, in this study they have compared with solar type stars that have massive planets close to it.
So, does this explain our Sun's low Lithium abundance? Well, according to me: No. Our solar system does not have a massive planet very close to it.
Do we know where to look to increase the chance of finding planets around other stars? Well, for solar type stars having massive planets close to them: yes, probably. To find planets like our own Earth? The study can't say anything about that.
Can we look at the abundance of every star and say which one is more likely to have planets: No, the study seem to only look at solar type stars.
Is media overexaggerating this news: Yes, as usual!
Although I'm sounding hard here I must say I like this study. It's an interesting study which may help us to understand the role a massive planet close to a star has in affecting the abundance of the star. I just think that media should be better in explaining the research. The BBC article I've linked to is okey: They actually write that it's solar type stars. But some of the articles don't say anything about the limitations of this study.
Are you interested in astronomy?
Posted by
Åsa Karlsson
| Courses I've studied at Uppsala University Math Introduction to Mathematics 3 points Algebra MN1 7,5 points Analysis MN1 15 points Linear Algebra MN1 7,5 points Analysis MN2 15 points Fourier Analysis with Applications 7,5 points ---------------------------------------------------- Math total: 55,5 points (60 points = 1 year) Computing Use of MATLAB 7,5 points Scientific Computing NV1 7,5 points ---------------------------------------------------- Computing total: 15,0 points (60 points = 1 year) Physics Science in Society MN1 7,5 points Quantum Physics and Astrophysics 9 points Mechanics MN1 7,5 points Mechanics MN2 7,5 points Wave Physics NV1 7,5 points Mathematical Methods of Physics NV1 7,5 points Electromagnetism MN1 7,5 points Solid State Physics MN1 7,5 point Thermodynamics MN1 7,5 points Statistical Mechanics MN1 7,5 points Theory of Special Relativity 4,5 points Quantum Mechanics MN1 7,5 points Electromagnetic field theory MN1 7,5 points ---------------------------------------------------- Physics total: 96,0 points (60 points = 1 year) Astrophysics The structure of the Universe 7,5 points Introduction to Astronomy 7,5 points Principles of Astronomy MN1 7,5 points Astrophysics II 5 points Physics of the Planetary System 10 points Radiation processes in Astrophysics 10 points Galaxies 10 points Cosmology 10 points Dynamical processes in astrophysics 10 points Celestial Mechanics 5 points Observational Astrophysics I 5 points Observational Astrophysics II 10 points ---------------------------------------------------- Astrophysics total: 97,5 points (60 points = 1 year) Thesis Image reduction and dust map construction of the local galaxy UGC08012 by using NOT observations | bryt | About Uppsala University Uppsala University (Swedish: Uppsala Universitet) is a research university in Uppsala, Sweden. Founded as early as 1477, it is the oldest such institution in the Nordic countries, and for centuries has been one of Europe's most renowned seats of learning. One of the main centres of higher education in Europe, the university rose to pronounced significance during the rise of Sweden as a Great Power at the end of the 16th century and was then given a relative financial stability with the large donation of King Gustavus Adolphus in the early 17th century. Uppsala also has an important historical place in Swedish national culture, identity and for the Swedish establishment: in historiography, literature, politics, and music. Many aspects of Swedish academic culture in general, such as the white student cap, originated in Uppsala. It shares some peculiarities, such as the student nation system, with Lund University and the University of Helsinki. Uppsala belongs to the Coimbra Group of European universities. The university has nine faculties distributed over three 'disciplinary domains'. It has about 40,000 students (20 000 full-time eq.), and about 2,000 doctoral students. It has a teaching staff of 4,000 (part-time and full-time) out of a total of 6,000 employees. Of its annual turnover of around 4.3 billion SEK (approx. 715 million USD), approximately 60% goes to graduate studies and research. Architecturally, Uppsala University has traditionally had a strong presence in the area around the cathedral on the western side of the River Fyris. Despite some more contemporary building developments further away from the centre, Uppsala's historic centre continues to be dominated by the presence of the university. Source: Wikipedia |
Newspapers I've been in Newspaper: Populär Astronomi, Sep 2009, No 3, Year 10, Page 22 Language: Swedish About: My homepage, my education and astronomy interest, and me moving to Australia. Pages: 4 Newspaper: Upsala Nya Tidning, Dec 7 2008, B6 Language: Swedish About: My homepage and my astronomy interest Pages: 4 | bryt | Articles I've written Popular scientific Newspaper: Populär Astronomi, Sep 2009, No 3, Year 10, Page 30 Language: Swedish Swedish title: Behövs verkligen mörk materia? English title: Do we really need dark matter? About: The MOND theory. Pages: 4 Popular scientific Newspaper: Populär Astronomi, Sep 2008, No 3, Year 9, Page 32 Language: Swedish Swedish title: Solens nya innehållslista English title: The Sun's new content list About: The chemical abundances in the Sun according to Martin Asplund et al. Pages: 4 |
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