Astronomy News August 28, 2015

I have always been interested in planets and stars which have been thrown out of orbit. They are commonly known as rogue and it is said many of them are sailing through space on a very lonely journey. The reason I am mentioning this is there is a new simulation which is showing there was a fifth gas giant planet in our solar system which was pushed out of orbit. The date has been said to be very accurate and would account for the positions of the planets now. Could there be a gas giant rogue planet from our solar system sailing through the galaxy? With as many solar systems which are predicted to exist in our galaxy this might not be as uncommon as one might think. While it might be a very small fraction of a percent, that might still be a lot of planets.

Since we are on the subject of rogue objects I have to talk about something very strange which has happened. Supernovae have been found which are not in a galaxy. It is believed these stars were relatively very young when they exploded and the power of their explosions blew them out of their galaxies. Wow that must have been some explosion. It wasn’t until the year 2000 that these types of supernovae were discovered. Previous to that this result was never dreamed of. When older photos were compared, it was found these supernovae were traveling along at the same speed as were stars which somehow were thrown out of our Milky Way galaxy. It is thought there may be a connection with these events and black holes. There may be a situation where somehow the power of a black hole contributes to the explosion of the supernovae. This brings me to another question, one more about my thoughts.

I have to wonder if a star is not only blown out of its galaxy, but planets somehow accompany it. This would mean there is a chance of life traveling through space in a solar system which is not part of a galaxy and is on its own. If this is possible it would be a rogue solar system. Some scientists claim there is no way planets could survive if their solar system was blown out of the galaxy and that the force required would destroy the planets. Even if this is true one has to wonder if a rogue star could pass near a rogue planet and pull it into an orbit around it. The odds of this happening are incredibly miniscule, but space is so big with so many objects in it one would have to think this must have happened at least a few times.

We are still studying Comet 67P/Churyumov-Gerasimenko. On August 13 it made its closest approach to the sun under the watchful eye of the Rosetta space vehicle. All sorts of stuff is burning off of the comet as it rotates while traveling. You can view the comet by copying and pasting this address into your browser’s address area, http://astronomynow.com/2015/08/14/rosetta-studies-comet-67p-at-perihelion/. Sorry About Facts does not use live links.

Almost every astronomer thought every large galaxy had a black hole at its center. That was until the fall of 2012. A new giant galaxy was found at that time. It was so big its diameter was ten times the size of our own Milky Way. As the galaxy was being examined, astronomers were scouring it for the black hole they believed was at its center. The more they searched the more puzzled they became. The astronomers couldn’t find the black hole. What they found was a diffuse core filled without any concentrated peak of light around a central black hole. Scientists still don’t rule out there being a black hole, but it doesn’t look like one is there and that this galaxy belongs to a new class of unusual galaxies, ones that don’t have a black hole at their center. The galaxy is known as A2261-BCG (short for Abell 2261 Brightest Cluster Galaxy).

The Cassini spacecraft has just made a flyby of Saturn’s moon Dione. This is not one of the moons we see mentioned very often. This will be the last time Cassini flies by it. Cassini has a bevy of tests it performs when flying near some large bodies. The close flight took place on August 17, 2015 and measured gravity. It took photos with a resolution of a few feet and mapped areas of unusual thermal anomalies. Even the dust from Dione is being analyzed by Cassini’s dust analyzer. The probe also looked for geologic activity. Cassini has been orbiting Saturn for many years. It has been there since 2004. The probe is nearing its last year and for that event it will dive between the planet’s rings and the planet itself gathering data all the way.

Astronomers are using NASA’s Chandra X-ray Observatory and the 6.5 meter Clay Telescope in Chile to study small supermassive black holes in hope of learning how they grow. The black hole they are studying is said to be about 50,000 the mass of our sun. So far it is the smallest black hole found in the center of a galaxy. One scientist made the following statement. “We found this little supermassive black hole behaves very much like its bigger, and in some cases much bigger, cousins. This tells us black holes grow in a similar way no matter what their size.” The black hole being studies is about 100 times less massive than the black hole in the center of our galaxy.

Scientists conducting a study on gravity now believe the force of gravity is constant throughout the universe. The study lasted for 21 years and used the Green Bank Telescope and Arecibo Observatory. They did this by measuring the steady tick of a pulsar known as PSRJ1713+0747.