Update on Extrasolar Planet Hunting
So as fate would have it two days after writing my most recent blog entry, an article was published with the title “First Picture of Planet around Sun-Like Star”. In my previous blog post I mentioned how we had only indirectly observed planets around other stars and had yet to photograph one directly. Well first I must say that even before this new discovery, my statement was not entirely correct. Some people within the last year have claimed that they had photographed planets around stars. I did not mention it because the jury is still out on these pictures as to whether or not what is seen is actually an orbiting planet or perhaps just a background object.
However, even with those couple of photos floating around, this new one is slightly more interesting. Those few photos we have so far of possible planets have all been around very dim stars called red dwarfs or even dimmer brown dwarfs. This new picture is of a star that is very much like our sun. The planet observed is giant (about eight times the mass of Jupiter) and lies far out from its star (about 330 times the Earth-Sun distance). It’s large mass, or size, is one the key factors in being able to view it directly. This planet is extremely far out from its host star; for frame of reference, Neptune is our farthest planet and lies only 30 times the earth-sun distance.
The discovery was made by the Gemini North Telescope on top of Mauna Kea, which is associated with the previously mentioned Subaru Telescope. However, more studies will have to be done to prove this object is in fact orbiting the observed star, but evidence from the indirect method of detection supports the idea that this is not just a background object in the picture.
Given the distance to its star and other strange qualities such as its large mass and hot temperature (about 1500C compared to Jupiter at 110C), we may have to really start looking at our models of planet formation. Currently our theories would not predict, or allow for, such a planet to be where it is and how it is. For those who want to see the pretty picture of the planet, Google the star name 1RXS J160929.1-210524 (nice name huh?) or should be available from the Gemini observatory’s website.
Tags: brown dwarf, gemini telescope, planet, red dwarf, subaru telescope