Tidal Disruption Events are spectacular to witness considering it is a supermassive black hole pulling in a star that got too close in its orbit. The result of such a phenomenon usually falls on the star losing half its mass to the black hole and the other half to be ejected at an incredible speed. Recently, Jon Miller of the University of Michigan, and his colleagues reported the nearest TDE so far. Galaxy PGC 043234 has a black hole, ASASSN-14li, at its center that recently shred a star to bits.

The event had a redshift of about 0.02 meaning the light had only traveled 290 millions years to reach the earth. This distance is close enough for astronomers to see the X-rays emitted by the star's gas falling into the black hole.

 Some of the gas was whipped outward and ejected, proven by the X-ray spectra that showed blueshifts in the tail of the gas. The blueshifts are an indicator that the gas is moving towards the earth and away from the black hole.

Below are the spectra that show the tail is being whipped towards us while the left shows a brief illustration of what it might look like.


More information can be found at skyandtelescope.com and the journal uploaded to nature.com by Miller and his colleagues.

Learning about the surfaces of celestial bodies gets more exciting as the technology to get data from these bodies improves. There are an infinite amount of questions that still hang in space outside our atmosphere, but there are an equal amount of questions within it. One of these questions, or many of them, deal with climate change and the change in the ocean currents.

Until recently, measurements in the ocean current changes were made by getting an estimate of the amount of water flowing north and south in the Atlantic using a network of buoys. Now NASA can observe the pressure changes in the flow of Atlantic currents using the dual satellite system GRACE. NASA's Gravity Recovery and Climate Experiment can measure the changes in the Earth's gravitational field. This is done by measuring the mass below the satellite. Through tons of data processing the important numbers were found and the pressure underneath the surface of the oceans was found and the changes indicated the flow of water in the currents along the Atlantic. A measurement of the meridional transport can be found by finding the differences in zonal pressures.

 

Below is an early concept of what data taken by GRACE might look like.


The article provided by nasa.gov has more information as does the prepublication of the paper behind the new research method.

Update on Charon

My first post was on New Horizon's HD images of Charon, one of Pluto's moons. New scans have shown an absorption peak at wavelengths near 2.2 microns over the Organa crater. This is particularly interesting considering we have been learning how to interpret absorption peaks in spectrum taken from sources like back bodies. A reading of 2.2 micron wavelengths coming out of a crater are an indication of the presence of ammonia meaning the possibility of an ammonia rich layer under a surface of frozen water.

Ammonia was first discovered on Charon as early as 2000, but the discovery of concentrated ammonia is interesting because the Organa crater is so close to the Skywalker crater, but their surface compositions are extremely different. Some scientists think that the ammonia located in the green highlights below is a result of the Organa crater being created much more recently than the Skywalker crater. Others believe that if there is a source of ammonia, an antifreeze if concentrated, under the frozen surface of Charon then it could be the cause for cryovolcanism and eruptions on the surface of Charon. This ties back to the resurfacing mentioned in my first post meaning the theories about an expansion of freezing water under the surface of Charon could be wrong.

It is important to remember that these are all theories. Some scientist doubt the ammonia is the result of Charon and could have been the byproduct of an asteroid hitting Charon's surface.

At any rate, more information can be found at these links: nasa.gov | discovery.com | areavoices.com

Fifth Giant Planet

For year centuries it was believed that the only existing bodies orbiting our sun where the ones that currently exist. In 2011 scientists proposed the possible existence of a fifth giant planet at the formation of the solar system. Since then it was thought that either Jupiter or Saturn was responsible for the missing planet. Astrophysicists at the University of Toronto have recently discovered that the ejection of the fifth gas giant was most likely produced by a gravitational interaction with Jupiter, having the fifth gas giant's velocity surpass the one necessary to escape the Sun's gravitational force. 

To find the culprit researchers created simulations of interactions between Jupiter, Callisto (one of Jupiter's moons), and the missing planet. They compared this to interactions between Saturn, Iapetus ( one of Saturn's moons, and the missing planet. It was determined that Callisto could return to its orbit around Jupiter while Iapetus could not. Ryan Cloutier, PhD candidate at University of Toronto's Department of Astronomy and Astrophysics  described Iapetus' hypothetical trajectory as "excessively unsettled" if the missing planet had been ejected by Saturn. 

More information on this fifth giant can be found at the Wikipedia article, earthsky.org, or phys.org.