Exoplanet HD95086 b

This image from ESO's Very Large Telescope (VLT) shows the newly discovered planet HD95086 b, next to its parent star. The observations were made using NACO, the adaptative optics instrument for the VLT in infrared light, and using a technique called differential imaging, which improves the contrast between the planet and its dazzling host star. The star itself has been removed from the picture during processing to enhance the view of the faint exoplanet and its position is marked. The exoplanet appears at the lower left.

The blue circle is the size of the orbit of Neptune in the Solar System.

The star HD 95086 has similar properties to Beta Pictoris and HR 8799 around which giant planets have previously been imaged at separations between 8 and 68 astronomical units. These stars are all young, more massive than the Sun, and surrounded by a debris disc.

Image credit: ESO/J. Rameau

Note: For more information, see Lightest Exoplanet Imaged So Far?

Debris Disk Around a White Dwarf Star

This illustration is an artist's impression of the thin, rocky debris disc discovered around the two Hyades white dwarfs. Rocky asteroids are thought to have been perturbed by planets within the system and diverted inwards towards the star, where they broke up, circled into a debris ring, and were then dragged onto the star itself.

Illustration credit: NASA, ESA, STScI, and G. Bacon (STScI)

Note: For more information, see Hubble Finds Dead Stars "Polluted" with Planetary Debris.

Kappa Coronae Borealis

Kappa Coronae Borealis, based on Herschel PACS observations at 100 μm. North is up and east is left. The star is in the center of the frame (not visible in this graphic) with an excess of infrared emission detected around it, interpreted as a dusty debris disc containing asteroids and/or comets. The inclination of the planetary system is constrained at an angle of 60º from face-on.

Image credit: ESA/Bonsor et al (2013)

Note: For more information, see Retired Star Found with Planets and Debris Disk.

WASP-12b

This artist's concept shows the searing-hot gas planet WASP-12b (orange orb) and its star. NASA's Spitzer Space Telescope discovered that the planet has more carbon than oxygen, making it the first carbon-rich planet ever observed. Our planet Earth has relatively little amounts of carbon -- it is made largely of oxygen and silicon. Other gas planets in our solar system, for example Jupiter, are expected to have less carbon than oxygen, but this is not known. Unlike WASP-12b, these planets harbor water, the main oxygen carrier, deep in their atmospheres, where it is difficult to measure.

Concentrated carbon can take the form of diamond, so astronomers say that carbon-rich gas planets could have abundant diamond in their interiors.

WASP-12b is located roughly 1,200 light-years away in the constellation Auriga. It swings around its star every 1.1 days. Because the planet is so close to its star, the star's gravity stretches it slightly into an egg shape. The star's gravity also pulls material off the planet into a disk around the star (shown here in transparent, white hues).

Illustration credit: NASA/JPL-Caltech

Note: For more information, see PIA13690: Signature of a Carbon-Rich Planet

BP Psc: Stellar Cannibalism

The composite image on the left shows X-ray and optical data for BP Piscium (BP Psc), a more evolved version of our Sun about 1,000 light years from Earth. Chandra X-ray Observatory data are colored in purple, and optical data from the 3-meter Shane telescope at Lick Observatory are shown in orange, green and blue. BP Psc is surrounded by a dusty and gaseous disk and has a pair of jets several light years long blasting out of the system. A close-up view is shown by the artist's impression on the right. For clarity a narrow jet is shown, but the actual jet is probably much wider, extending across the inner regions of the disk. Because of the dusty disk, the star's surface is obscured in optical and near-infrared light. Therefore, the Chandra observation is the first detection of this star in any wavelength.

The disk and the jets, seen distinctly in the optical data, provide evidence for a recent and catastrophic interaction in which BP Psc consumed a nearby star or giant planet. This happened when BP Psc ran out of nuclear fuel and expanded into its "red giant" phase.

Jets and a disk are often characteristics of very young stars, so astronomers thought BP Psc might be one as well. However, the new Chandra results argue against this interpretation, because the X-ray source is fainter than expected for a young star. Another argument previously used against the possible youth of BP Psc was that it is not located near any star-forming cloud and there are no other known young stars in its immediate vicinity. The Chandra image supports this absence of a cluster of young stars, since multiwavelength studies show that most of the X-ray sources in the composite image are likely to be rapidly growing supermassive black holes in the centers of distant galaxies.

Credits: X-ray (NASA/CXC/RIT/J.Kastner et al), Optical (UCO/Lick/STScI/M.Perrin et al); Illustration: NASA/CXC/M.Weiss

Beta Pictoris b

This story is a little old, having come out back in June, but there aren't any other new stories to report on at the moment.

For the first time, astronomers have been able to directly follow the motion of an exoplanet as it moves to the other side of its host star. The planet has the smallest orbit so far of all directly imaged exoplanets, lying as close to its host star as Saturn is to the Sun.

The team of astronomers used the NAOS-CONICA instrument (or NACO), mounted on one of the 8.2-meter Unit Telescopes of ESO's Very Large Telescope (VLT), to study the immediate surroundings of Beta Pictoris in 2003, 2008 and 2009. In 2003 a faint source inside the disc was seen, but it was not possible to exclude the remote possibility that it was a background star. In new images taken in 2008 and spring 2009 the source had disappeared! The most recent observations, taken during autumn 2009, revealed the object on the other side of the disc after having been hidden either behind or in front of the star. This confirmed that the source indeed was an exoplanet and that it was orbiting its host star. It also provided insights into the size of its orbit around the star.

The above composite shows the reflected light on the dust disc in the outer part, as observed in 1996 with the ADONIS instrument on ESO's 3.6-meter telescope. In the central part, the observations of the planet obtained in 2003 and autumn 2009 with NACO are shown. The possible orbit of the planet is also indicated, albeit with the inclination angle exaggerated.

Photo credit: ESO/A.-M. Lagrange