GIANT PLANETS IN PROTOPLANETARY DISKS WITH SPIRAL ARMS?

There are many theories about the formation of the planets but the direct observational evidences are quite a few. Recently, the ground-based telescopes photographed two large spiral arms around two young stars. The mechanisms that have generated these structures are not very clear.

Recent studies based on computer simulations suggest that such structures may indicate the presence of giant planets "invisible" (too faint to be seen with existing tools). A comparison between simulations and direct observations may be able to obtain not only the position of the planet but also its mass.
The method proposed in addition to opening a new avenue for detecting extrasolar planets also offers a new look at the mechanisms that act in the early stages of planet formation.

To know more:
http://arxiv.org/abs/1507.03596
http://arxiv.org/abs/1507.03599
http://arxiv.org/abs/1511.01178
http://arxiv.org/abs/1412.3412
http://hubblesite.org/newscenter/archive/releases/2015/40/full/

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Protoplanetary disks in the hostile environment of Carina

Image: Star-forming region in the Carina Nebula. Credit: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA) In a recent paper (Mesa-Delgado et al. 2016) [1] the authors report the first direct imaging of protoplanetary disks in the star-forming region of Carina, the most distant, massive cluster in which disks have been imaged.

A Sapphire Super-Earth

Twenty-one light years away, in the constellation Cassiopeia, a planet by the name of HD219134 b orbits its star with a year that is just three days long. With a mass almost five times that of Earth, it is what is known as a super-Earth. Unlike our planet, however, these super-Earths were formed at high temperatures close to their host star and contain high quantities of calcium, aluminum and their oxides – including sapphire and ruby. HD219134 b is one of three candidates likely to belong to a new, exotic class of exoplanets. These objects are completely different from the majority of Earth-like planets. They have 10 to 20 percent lower densities than Earth. Researchers looked at different scenarios to explain the observed densities. For example, a thick atmosphere could lead to a lower overall density. But two of the exoplanets studied, 55 Cancri e and WASP-47 e, orbit their star so closely that their surface temperature is almost 3,000 degrees and they would have lost this ...

A BINARY ORIGIN FOR A CENTRAL COMPACT OBJECT (CCO)?

Figure: False-Colour X-ray and infrared emission image from the core of the infrared shell. The RGB colours correspond to Chandra X-ray 0.2-10 keV (blue), IRAC infrared 8 μm (green), and HPACS 70 μm (red) data. The intensity scale is logarithmic for all channels. Overlaid are equal brightness levels from the MIPS 24 μm band. Note that around the CCO the infrared emission is suppressed in the 70 μm band and enhanced in the 24 μm band suggesting higher dust temperature. Credit: Doroshenko et al 2016 Central compact objects (CCOs) are thought to be young isolated neutron stars that were born during the preceding core-collapse supernova explosion.

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