We all know that super massive black holes lurk in the center of galaxies. We know that they can have strong impacts on the surroundings; usually we can see how things are being impacted by the outflows of energetic particles being ejected from feeding black holes. However, if a black hole is not active and does not have jets usually we cannot see anything left over, any remnants from its energetic past. Well recently using the Chandra X-ray observatory a ghost of an eruption from a massive black hole has been observed and may have some interesting things to tell us.

The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source HDF 130 is over 10 billion light-years away a time when galaxies and black holes were forming at a high rate. Scientists think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced large amounts of radio and X radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy.

However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so.

This is the first X-ray ghost ever seen after the demise of radio-bright jets. Astronomers have observed extensive X-ray emission with a similar origin, but only from galaxies with radio emission on large scales, signifying continued eruptions. In HDF 130, only a point source is detected in radio images, coinciding with the massive elliptical galaxy seen in its optical image. This radio source indicates the presence of a growing supermassive black hole.

The power contained in the black hole eruption was likely to be considerable, equivalent to about a billion supernovas. The energy is dumped into the surroundings and transports and heats the gas. Because they’re so powerful, these eruptions can have profound effects lasting for billions of years.

The data tells us that there should be many more such ghosts lurking around out there, especially if black hole eruptions are as common as are thought in the distant universe. This is a good discovery as it tells us that we do not have to catch a black hole in the act to witness the big impact they can have. Using Chandra I’m sure searches will begin for other such remnants. Once we have found more of them we can search for patterns in the data, see if there are commonalities in these eruptions or links between the data and other such things such as the mass of the black hole. 

Modern develops in hunting for planets outside of our own solar system have yielded the discovery of well over a hundred different planets now. These newer methods include very new telescopes with the resolving power of being able to actually see an exoplanet, with which only 1 so far has been confirmed photographed, and other methods include using radial stellar velocity, or the Doppler effect, and the transit method. Now for the first time since its inception 50 years ago the method of astrometry has found an exoplanet.

The method of astrometry was first thought of 50 years ago to search for planets outside our solar system, called exoplanets. It involves measuring the precise motions of a star on the sky as an unseen planet tugs the star back and forth. But the method requires very precise measurements over long periods of time, and until now, has failed to turn up any exoplanets. This method is different from the more commonly used method of using the Doppler Effect or radial velocity of a star. Most exoplanets have been detected by watching for a wobble of a star, a gravitational tug from an orbiting planet due to the Doppler Effect. Astrometry also looks for a wobble but it is different  it measures the displacement the planets cause in their parent star’s apparent position on the sky, due to their mutual orbit around the center of mass of the system.

Two astronomers from NASA’s jet propulsion laboratory in California have been collecting data for the past 12 years from an instrument mounted on a telescope at the Palomar Observatory near San Diego. After looking at data from 30 different stars they have finally found what they were looking for: a planet surrounding the star VB 10. The planet itself is about 6 times the mass of Jupiter and an orbit a bit farther out making a cold Jupiter.  The star itself is quite small, a dwarf, at only 1/12 the mass of the sun. For a long time VB 10 was known as one of the smallest stars and now is the smallest star with a planet around it.  Because the star is so small, its planetary system would be a miniature, scaled-down version of our own. For example, VB 10b is located about as far from its star as Mercury is from the Sun. Any rocky Earth-sized planets that might happen to be in the neighborhood would lie even closer in.

The finding confirms that astrometry could be a powerful planet-hunting technique for both ground- and space-based telescopes. For example, a similar technique would be used by SIM Lite, a NASA concept for a space-based mission that is currently being explored. This is an exciting discovery because it shows that planets can be found around extremely lightweight stars. It seems that nature likes to form planets, even around stars quite different from our Sun. Now that it’s proven that this technique actually works and yields results it seems likely others might take it up, and more exoplanets will be found. One more tool in the planet hunter’s arsenal; one step possibly closer to finding a planet like our own.�

Scientists from the Max Plank Institute for Radio Astronomy in Bonn Germany using NASA’s Fermi Gamma Ray Space Telescope and the world’s largest radio telescope array have solidified a theoretical link between radio jets coming from the center of active galaxies and gamma ray bursts. This is a fine demonstration and use of new technology combined with an innovative use of existing technology.

Active galaxies are extremely bright galaxies which emitted oppositely directed jets of charged particles from their centers traveling near the speed of light.  Some, called Blazars, are especially bright because their jets are orientated along our line of sight.  These jets glow brightly in the radio part of the spectrum and in the 90’s it was hinted with the Chandra X-ray Observatory that they might emit in the higher energy parts of the spectrum as well. Astronomers believe these jets arise from matter that is falling into the central massive black holes of the galaxies, but the exact processes behind them is not well understood; which makes them the object of much study.

Now the Fermi telescope uses it’s Large Area Telescope, LAT, to scan the entire sky every 3 hours getting snapshots of the gamma ray bursts throughout the sky and monitor flares. Gamma ray bursts are the highest energy form of light below cosmic rays, and the origins of these gamma ray bursts is still undetermined; the objective of Fermi is to help clarify these origins. 

The new study was part of the MOJAVE program, which is a long-term study of the jets form active galaxies using primarily the VLBA. The VLBA is the National Science Foundation’s Very Long Baseline Array, a set of 10 radio telescopes located from Hawaii to the Virgin Islands and operated by the National Radio Astronomy Observatory in New Mexico.  Signals from these 10 different telescopes are combined and the array acts like a single enormous radio dish more than 8,500 kilometers across. The VLBA can resolve details about a million times smaller than Fermi and50 times smaller than any optical telescope.

Astronomers combined data from the VLBA and LAT. Active galaxies detected in the LAT’s first few months of operations generally possess brighter and more compact radio jets than galaxies the LAT did not see. Moreover, an active galaxy’s radio jets tend to be brighter in the months following any gamma-ray flares observed by the LAT.  A correlation was also found between active galaxies with the brightest gamma ray emission and those with the fastest jets.

The scientists were also able to use this data to study a phenomenon known as Doppler boosting. Doppler boosting makes radio-emitting blobs look brighter and appear to move faster than the speed of light due to the angle at which it is viewed and the fact the speed of the particles is close to the speed of light.  The VLBA data shows that the bigger the Doppler boost seen in a radio jet, the more likely it is that Fermi recorded it as a gamma ray source. Also, many objects found by Fermi to be extreme in gamma rays are broadcasting strong bursts of radio emission at the same time. 

All of this data points to the conclusion that the portion of an active galaxy’s radio jet closest to the galaxy’s center is also the source of the gamma rays.  These findings show us a very interesting and before unknown link between two “sides” of one object and possibly one process. This may bring astronomers one-step closer to solving two very large mysteries: the processes behind the jets and the exact processes or origins of gamma ray bursts. It could turn out to be quite nice and convenient if both questions could have the same answer, or an answer that comes from the same place. This new finding is also a demonstration of the use of the new technology of Fermi the space telescope that was designed just to study gamma ray bursts, a first of its kind, and the technology behind the VLBA, using standard radio telescopes in a new way to improve their usefulness. 

The largest mirror ever to be launched into space now has a set launch date.  The European Space Agency’s Herschel Space Observatory and Planck Satellite are set to launch into space May 6^th. . Together these two pieces of equipment should be bringing in lots of new and exciting information about our own solar system and distant galaxies.

Sir Frederick William Herschel was a German born British astronomer from the 18^th and 19^th century. He was most famous for discovering the planet Uranus and discovering infrared radiation.  The Herschel Space Observatory will be the first to cover the full far infrared and sub-millimeter telescope.  The large mirror measures in at 3.5 meters; it’s a novel and advanced concept using 12 silicon carbide petals brazed together into a single piece. It is one of the major technological highlights of the mission.  Herschel will be investigating a large array of astronomical objects including: galaxy formation in the early universe and galaxy evolution, star formation and its interaction with the interstellar medium, chemical composition of atmospheres and surfaces of solar system bodies, and molecular chemistry across the universe.  Sounds like it has it work cut out.

The Planck Satellite will be going up with Herschel Observatory.  The satellite is named after the famous German physicist Max Planck who is considered the founder of quantum theory.  The satellite was designed to observe the anisotropies of the cosmic microwave background radiation, or CMB, over the entire sky using high angular resolution.  The mission is meant to improve upon the data collected from the well-known WMAP mission and will be used to test theories of the early universe and the origin of cosmic structure. 

Herschel and Planck will start their journey in space on board an Ariane 5 departing from Europe’s Spaceport in Kourou, French Guiana. Final preparations for the launch are now being made such as fueling the two satellites and filling Herschel’s cryostat (a vessel used to maintain cryogenic temperatures) with helium.  Once launched the two satellites will separate and be put into separate orbits around the second lagrangian point of the earth-sun system, a distance of about 1.5 million km’s from Earth.  Both satellites are part of the European Space Agency’s Horizons 2000 Scientific Programme, which consisted of about 15 satellite or telescope projects over the last 20 years including such other projects as Cluster, Huygens, XMM-Newton, and others.

The launch of these two satellites/observatories is exciting. They are new and advanced pieces of technology aimed at answering some large questions in astronomy today.  And are a fine example of astronomy goals and projects outside of the US.  So for now we just have to keep our fingers crossed and hold our breath for a successful launch and problem free start up. 

Observational astronomers, engineers, and telescope experts are always working hard to better their observational equipment.  Even with all of our advanced technology when looking at things at such great astronomical distances we are still limited. However, recently astronomers in Germany made a break through with a new technique for improving resolution power of telescopes, allowing us to see previously unseen objects or resolve new details of known objects.

A team of astronomers, led by Stefan Kraus and Gerd Weigelt from the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany, used European Southern Observatory’s (ESO) Very Large Telescope Interferometer (VLTI) to obtain the sharpest image of the young double star Theta 1 Orionis C in the Orion Trapezium Cluster.  The Theta 1 system is a massive binary system of young stars in the Orion star-forming region. In previous images of the system, even with the Hubble Space Telescope, the telescopes were not able to resolve the two separate stars in the system, which are only separated by a distance of about 20 milliarcseconds.  The team was also able to derive the properties of the system including the masses of the two stars, about 38 and 9 solar masses, and also an accurate measure of the distance to the system, about 1350 light years.

The increase in resolution power came from using the technique of interferometry.  This method allows one to combine light collected from several telescopes, making what is like a “virtual” telescope with a resolving power equal to that of a ground based telescope with a 200 meter mirror or a space based telescope with a 130 meter mirror.  The Very Large Telescope now allows European astronomers to reconstruct images from the interferometric infrared data with the use of its near infrared beam combination instrument AMBER.  This gives the astronomers a resolving power of about 2 milliarcseconds.

Early imaging interferometry was almost exclusively done with long wavelength radio telescopes because the longer the wavelength of incoming radiation the easier it is to measure the phase information of data. Examples of radio interferometers are the Very Large Array, or VLA, and The Multi-Element Radio Linked Interferometer Network, or MERLIN. As the speeds of correlators and associated technologies have improved, the minimum radiation wavelength observable by interferometry has decreased. Now this is the first time astronomers have been able to use this technique with the shorter wavelength of infrared.

So far this technique with the VLIT has only been used to study Theta 1 in the Orion region.  The results obtained will be important for studying the Orion region and for theoretical models of massive star formation, as Theta 1 is a particularly massive and young star in an active star forming region.  Beyond the Orion data this method for observing promises to yield new discoveries and information about many different objects and topics. It is quite exciting innovation bringing us closer to new information without the need for necessarily spending much more time and money on new equipment. 

Melbourne, FL (March 24, 2009) – This spring, the Emerald Book Company will bring the universe to your local bookstore.

Our Undiscovered Universe: Introducing Null Physics is for anyone who has ever questioned the universe and its origins. For years, the public only had two places to turn for answers about the universe: the Big Bang and “alternative theories.”  In Our Undiscovered Universe , Witt addresses the foundation of reality through a new theory–Null Physics. This theory tells readers the why, how, and what of the universe. Recently, the subject matter was published in the January 2009 issue of Physics Essays. Physics Essays is published by Physics Essays Publication through the American Institute of Physics.

“I am overjoyed to be working with Emerald Book Company,” said Terence Witt, author of Our Undiscovered Universe . “Their contribution will ensure more readers will enjoy studying Null Physics and I look forward to discussing the theory.”

Terence Witt has a web page associated with Emerald Book Company that includes biographical information, press releases, dates of upcoming media appearances, as well as peer quotes.

Look for Our Undiscovered Universe soon at your local bookstore.

About Terence Witt
Terence Witt is the founder and former CEO of Witt Biomedical Corporation. He holds a BSEE from Oregon State University and is a visiting scientist at Florida Institute of Technology. Witt lives in Florida with his wife Ginny and enjoys scuba diving, playing tennis, and piloting planes. Our Undiscovered Universe: Introducing Null Physics is available through Ingram Books, Baker & Taylor, or directly through Emerald Book Company. Emerald Book Company is a division of Greenleaf Book Group, LP. Go to www.OurUndiscoveredUniverse.com for more information.

It has been observed for some time now that most large galaxies have super massive black holes at their center. It is generally believed that all galaxies have a central black, but some have thought for a while now that large galaxies may have more than one central black hole.  However, until very recently a binary black hole system had never been observed.  Astronomers from the National Optical Astronomy Observatory, NOAO, in Tucson AZ have found what they believe is the first binary system of two massive black holes.

The astronomers from NOAO used data from the Sloan Digital Sky Survey, SDSS, to look at quasars billions of light years away. More than 100,000 quasars are known while the astronomers for this study looked at 17,500 quasars from SDSS data.  A quasar is a quasi-stellar radio source; a powerfully energetic and distant galaxy with an active nuclei. They are hundreds of times brighter than our own galaxy and powered by matter falling into the black hole, or accreting, and as the matter falls in it heats up dramatically causing a luminous glow.

Astronomers are able to use “see” the central black hole by looking for a particular signature in the radiation coming from the in falling matter.  Now with two central black holes they would be too close together to actually distinguish their own accretion disks however there should be a characteristic dual signature in the emission lines.  It was this distinct signature that NOAO astronomers were looking for, and believe they have found.

Once the signature was detected the scientists had to rule out the possibility that it was coming from two separate galaxies in the same line of sight superimposed on each other. It took some work but they were able to determine that the emissions were coming form the same distance with only one possible host galaxies.  The double set of broad emission lines is pretty conclusive evidence that what was being seen is a binary black hole system. The smaller of the two black holes is estimated at about 20 million solar masses while the larger one is about 50 times bigger, as determined by their orbital velocities. 

This is an exciting discovery as it is the first of its kind. Further study can be used to research theories on galaxy mergers, super massive black hole evolution, and theories on gravity and relativity. It is theorized that galaxy mergers happen frequently and if each galaxy had a central black hole a merger would create a binary like this one. This theory also predicts that the two black holes will eventually merge themselves, evidence of which should, if theory is correct, be observable within the next few years. Also this is an ideal place to study theories of gravity and relativity, as the gravitational pull from a massive black hole binary system would be so strong gravitational effects not normally observable would be present.  It should be quite interesting to see what research and information comes from further study of this system. 

The year 2009 is the international year of astronomy; it marks 400 years since Galileo used the telescope to first look up at space. As part of the celebration NASA and other astronomical societies having been doing things to celebrate.  NASA is doing its part this month by allowing the public to be the astronomers. They have put the public in control of the Hubble Space Telescope. NASA has picked six astronomical objects and is allowing the public to vote on which object Hubble will view and collect data on next. I decided to go over each of the six objects and describe what they are and why they might be of interest.

The first object is a star-forming region called NGC 6334 also known as the Cat’s Paw Nebula or the Bear Claw Nebula. It is located in the Scorpius constellation that is located in the southern hemisphere near the center of the galaxy.  It is located about 5,500 light years away. It glows with a deep red color that originates from a large amount of ionized hydrogen in the area. The nebula is usually obscured by large amounts of gas and dust sometimes making it difficult to observe from ground based telescopes.  The region is a very active star-forming region, which is the reason it is considered for observation. Observing these star forming regions tells us a lot about the birth and evolution of stars, and the interaction of a large number of young stars in close proximity to each other.

The second contestant is the planetary nebula NGC 6072, which is also located in the constellation Scorpius. There is not much information available on this object and it has not been viewed very often.  It is a remnant of a dead low mass star; a white dwarf with an envelope of gas and molecules surrounding it that were puffed off layers of the star as it was dying. Observing planetary nebulas is always useful, it gives us information about stars after they die and how the elements given off interacts with surrounding gas and dust. They also usually make for very pretty pictures.

The third object is planetary nebula NGC 40, otherwise known as the Bow-Tie Nebula. It is located about 3,500 light years form Earth in the constellation Cepheus. It is also composed of hot gas surrounding a dying/dead star. The white dwarf left behind radiates at about 50,000 degrees C and the gas envelope at about 30,000 degrees C.  This nebula has been imaged more than the other nebula, perhaps making it a less attractive candidate.

The fourth object in the contest is the spiral galaxy NGC 5172.  It is located at a distance of about 57 mega parsecs or about 150 million light years. It is a spiral type Sbc. IT has been a host to several well-documented supernovae. From what we can tell it is very similar in size and shape to our own Milky Way galaxy, which is the reason it may be a good candidate for study. Since we can not get an outside looking in view of our own galaxy studying ones similar to our own tell us information we could not otherwise get.

The next possible object is the edge on galaxy known as NGC 4289. It is located in the Virgo Constellation about 50 million light years away.  It is also a spiral galaxy but instead of being viewed face on it is seen completely edge on.  There are advantages to looking at the same types of things from different views; especially with astronomy. When looking at things so far away with things obstructing your view, light traveling so far, being bent around objects being able to see galaxies edge on can help with verifying measurements of brightness, velocity and other variables.

The last option for an object to choose is Arp 274, or NGC 5679, and is actually two (possibly three) galaxies interacting with each other.  It is also located in the Virgo constellation. Interacting galaxies are treasure-troves of data. By studying them we can information on formation and evolution or galaxies. We get information on how these interactions affect star formation, surrounding galaxies, central black holes, and more. I think this is a great candidate for further study. 

So those are the six objects open for voting. I encourage any readers to go check out NASA’s site and vote. I personally think this was a great idea on NASA’s part. Hubble has always been very popular and a great tool for creating public interest in astronomy, which can at times be hard to do.  I think it’s smart to give the general people the option to pick what they think is interesting and what they want to know more about. I encourage anything that the industry wants to do to try and rose public support, especially in times when funding is hard to come by NASA needs to keep the public in its corners.  I’m excited to see who the winner will be. 

The Apollo missions of the 1970’s can be credited with many great discoveries–the most notable of which, were the six missions that sent twelve astronauts to the moon.  During these manned missions to the Moon, rock samples were collected and returned to the Earth.  The analysis of these samples led to the current hypothesis of lunar formation.  This hypothesis suggests that the Moon was formed by a catastrophic collision between Earth and Mars-sized planetesimal.  After this collision, the Moon would have been covered by a thick blanket of magma, which cooled to form a crust much different from the Earth’s crust.   Then 3.8 billion years ago, during the late heavy bombardment, the Moon’s surface was pounded by meteor impacts, leaving the surface deformed and heavily cratered.  New data gathered by the Japanese mission, SELENA, may offer new insights into the formation of the moon.

SELENA focused on the differences between the near and far side of the moon, such as: compositional, gravitational, topographical, and tectonic differences.   However, it is difficult for spacecrafts to relay information from the far side of the Moon, due to the fact that the Moon is tidally locked to the Earth.  SELENA was able to surmount this obstacle by using a companion satellite positioned in an elliptical orbit at a higher altitude.  This companion satellite was then able to relay information between Earth and SELENA. 

Because the Moon is a homogeneous body, there are several differences between the near (Earth facing) and far-side of the Moon.  The nearside of the Moon is covered by dark basaltic plains, (the very features that Galileo once mistook for seas).  The far side of the Moon is much more heavily cratered, and the higher elevations are composed of a bright material. These compositional differences are accompanied by differences which are intrinsic properties of the materials that make up each side of the Moon, such as crustal thickness and density.  Other differences between lunar faces include volcanic activity and surface age.

Another key difference between the lunar faces is the gravitational anomalies found on either side of the Moon.   These differences in gravitational anomalies can be used to deduce possible density differences of the interior.  Positive gravitational anomalies on the nearside of the Moon have been known about for several years and are associated with the large areas of basaltic planes.  These planes are referred to as mascons (mass concentrations).    These mascons could be the result of basaltic magma filling basins after basin formation, or they could be the result of mantle uplift that could have occurred during a large impact event.  SELENA was able to map the gravitational anomalies of the lunar far-side for the first time.  What SELENA discovered was that the far-side mascons have small central positive gravitational anomalies that are surrounded by a wide ring of negative anomalies.  These differences in gravitational anomalies observed on either side of the Moon could suggest that the far-side of the Moon may have had much cooler and rigid conditions in its early history.  

SELENA also used a Lunar Radar Sounder to map subsurface stratigraphy beneath the nearside basaltic basins.  The results of this experiment show that the thickness of the most recent volcanic flows may have been deformed compressive stresses that occurred during a period of global cooling, and not entirely because of the stresses which occurred during mascon formation.

The terrain camera onboard SELENA was able to photograph volcanic flows on the lunar far-side.  These photos were then used to estimate the age of the far-side basalts using cratering statistics. Based on the cratering statistics, the age of the lunar far side was found to be much younger than the lunar nearside, with volcanic activity continuing to make fresh surface until approximately 2.5 billion years ago.

Although the data gathered so far is not enough to paint a clear picture of lunar evolution, it has become clear that the mascons formed much differently on either side of the Moon during late heavy bombardment.  To help interpret these discoveries, new data will be on its way as China, India, and the United States all have orbiters slated for lunar observation in the next couple of years.  In the meantime we are left to wonder, are these differences due to external processes such as a giant impact, or are they due to internal processes such as core formation, and crustal differentiation?  One thing seems clear, the difference in surface age on either side of the Moon will be an important variable when devising a model for lunar evolution.

Using the Hubble Space Telescope, NASA scientists have discovered stars doing something very interesting: speeding around through the interstellar medium.  This came as quite a surprise especially since they were not even looking for them. This is not usual behavior for stars and brings up many new questions about what these stars are doing and why.

The scientists discovered 14 of these crazy runaway stars.  Because of their movement it was harder to gather information about them but scientists were able to deduce some facts about the stars. The stars appear to be young, maybe only about a million years old.  This was deduced from looking a their strong stellar winds. Most stars only have such winds when they are quite young or very old. The nebulae around the stars do not math that of those typically seen around old dying stars. And only very massive stars have winds throughout their lifespan, but these stars could not be that massive because they do not have glowing clouds of ionized gas around them. They are estimated to be about 2 to 8 solar masses.

These stars plow through regions of dense interstellar gas creating brilliant arrowhead shaped glowing bow shocks and trailing tails of glowing gas. These bow shocks are created when the strong winds coming from the stars slam into the surrounding dense gas. It’s difficult to tell their exact distance from Earth but depending on the distance these bow shocks could be 100 billion to a trillion miles wide. By studying these bow shocks we can tell that the stars are moving very quickly, about 180,000 km/hr.  All stars are moving as they are orbiting around the galaxy but not nearly at these speeds, the sun for comparison moves through the galaxy at only about 13,000 km/hr.  Assuming this “young” phase lasts only a million years the stars would have traveled about 160 light years.

The scientists have hypothesized that these stars were likely kicked out or ejected from massive star clusters.  There’s two possible ways this expulsion could have happened.  One way is if a binary system, consisting of two stars orbiting each other, had one star go supernova the explosion would eject the companion star.  The other possibility would be if two binary systems or a binary and a third star collided one of the stars could have used he energy from the interaction to escape the system.

Runaway stars have been observed before, the first being found in the late 80s. However, those stars produced much larger bow shocks meaning they were probably more massive with larger stellar winds.  Scientists think these new objects, the medium size stars, are probably more common since medium sized stars are more common in general and because they would be more susceptible to being ejected.  These objects are difficult to find and observe because one doesn’t know where to find them or where to look for them. 

Follow up studies are planned to look for more of these objects, called interlopers, and to study these recently discovered ones. Further studies will tell us more about the effects these speed demons have on the environments they pass by or interact with. Theorists and modelers will have to set to work on looking at the origins of the objects and the causes of their ejections. Pretty interesting to think about these stars being expelled from their homes now doomed to zoom around the galaxy alone.