Space and astronomy news
Astronomers have found a core burning star, like our own Sun, that’s only 16% larger than Jupiter; although, it has 96 times as much mass. The observations were made using the European Southern Observatory’s 8.2m VLT Kueyen telescope in Chile. Astronomers watched tracked 60 stars which were known to have a regular dip in brightness, when a dimmer object was passing in front. This survey found 7 of these low mass stars which eclipsed their brighter companion.
Astronomers using the Gemini observatories have got themselves a bit of a mystery. They’ve found a binary system at EF Eridanus, located 300 light-years away from Earth, where one of the objects defies classification. It’s about the size of Jupiter but it’s way too massive to be a planet. It’s the temperature of a brown dwarf, but its light doesn’t match a brown dwarf’s characteristics. The researchers believe that the object was once a regular star, but then it had most of its material stripped away by the gravity of the larger star over the course of 5 billions years. Eventually it just couldn’t give any more.
A team of European and US astronomers think they’ve taken the first direct image of a planet orbiting another star about 230 light-years away. Until now, planets have been discovered because of the effect they have on their parent star – they haven’t been “seen” directly. Using the European Southern Observatory’s 8.2-m telescope in Chile, the team found a faint, red object nearby a brown dwarf star called 2M1207. By analyzing the object with various instruments, they believe the object is approximately 5 times the mass of Jupiter. There’s still some uncertainty, though, so the team will make regular observations over the next 2 years to see how its position and composition changes.
A team of European astronomers have used the European Southern Observatory’s HARPS Instrument to find the smallest extrasolar planet ever discovered; it’s believed to be only 14 times the mass of the Earth. The planet orbits a star called mu Arae every 9.5 days, which is located 50 light-years away in the southern constellation of the Altar. A planet this size lies right at the boundary between rocky planets and gas giants. But since it’s so close to its parent star, it’s probably rocky, with a relatively small atmosphere, so it would be classified as a “super Earth”.
European astronomers have confirmed a new class of objects, known as “very hot Jupiters”, which are large, extremely hot, and orbit their parent star in an orbit that only takes a couple of days. They used the “transit method”, which measure the brightness of a star over a long period of time to watch for a periodic dimming; an indication that a planet is passing in front. As part of a new survey of 155,000 stars, the astronomers have found 137 transit candidates, and confirmed 2 planets so far using other techniques for finding extrasolar planets.
The European Southern Observatory has released the most detailed images ever taken of the surface of Titan, Saturn’s largest moon. The images were taken using a new instrument called the Simultaneous Differential Imager (SDI), which was originally designed to help image extrasolar planets. The images show a number of surface regions with different reflectivity, including several dark areas with very low reflectivity, which could be huge reservoirs of liquid hydrocarbons. Scientists will get a better look when the Huygens probe arrives in early 2005.