Within the Milky Way, there are an estimated 200 to 400 billion stars, all of which orbit around the center of our galaxy in a coordinated cosmic dance. As they orbit, stars in the galactic disk (where our Sun is located) periodically shuffle about and get closer to one another. At times, this can have a drastic effect on the star that experience a close encounter, disrupting their systems and causing planets to be ejected.
Knowing when stars will make a close encounter with our Solar System, and how it might shake-up objects within it, is therefore a concern to astronomers. Using data collected by the Gaia Observatory, two researchers with the Russian Academy of Sciences (RAS) determined that a handful of stars will be making close passes by our Solar System in the future, one of which will stray pretty close!
Continue reading “In 1.3 Million Years, a Star Will Come Within 24 Light-Days of the Sun”
In 1915, Einstein put the finishing touches on his Theory of General Relativity (GR), a revolutionary new hypothesis that described gravity as a geometric property of space and time. This theory remains the accepted description of gravitation in modern physics and predicts that massive objects (like galaxies and galaxy clusters) bend the very fabric of spacetime.
As result, massive objects (like galaxies and galaxy clusters) can act as a lens that will deflect and magnify light coming from more distant objects. This effect is known as “gravitational lensing,” and can result in all kinds of visual phenomena – not the least of which is known as an “Einstein Cross.” Using data from the ESA’s Gaia Observatory, a team of researchers announced the discovery of 12 new Einstein Crosses.
Continue reading “Gaia Finds 12 Examples of Einstein Crosses; Galaxies Being Gravitationally Lensed so we see Them Repeated 4 Times”
Spiral galaxies are one of the most commonly known types of galaxy. Most people think of them as large round disks, and know that our Milky Way is counted among their number. What most people don’t realize is that many spiral galaxies have a type of warping effect that, when you look at them edge on, can make it seem like they are forming a wave. Now scientists, led by Xinlun Chen at the University of Virginia, have studied millions of stars in the Milky Way and begun to develop a picture of a “wave” passing through our own galaxy.
Continue reading “You Can Actually See the Milky Way’s Wave When You Map Its Stars”
Within our galaxy, there are thousands of stars that orbit the center of the Milky Way at high velocities. On occasion, some of them pick up so much speed that they break free of our galaxy and become intergalactic objects. Because of the extreme dynamical and astrophysical processes involved, astronomers are most interested in studying these stars – especially those that are able to achieve escape velocity and leave our galaxy.
However, an international team of astronomers led from the National Astronomical Observatories of China (NAOC) recently announced the discovery of 591 high-velocity stars. Based on data provided by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and the ESA’s Gaia Observatory, they indicated that 43 of these stars are fast enough to escape the Milky Way someday.
Continue reading “Astronomers Discover Hundreds of High-Velocity Stars, Many on Their Way Out of the Milky Way”
In 2013, the European Space Agency (ESA) deployed the Gaia mission to space, a next-generation observatory that will spend the next five years gathering data on the positions, distances, and proper motions of stars. The resulting data will be used to construct the largest 3D space catalog ever, totaling 1 billion stars, planets, comets, asteroids, quasars, and other celestial objects.
Since the mission began, the ESA has issued three early releases of Gaia data, each of which has led to new research findings and more detailed maps of our galaxy. Based on the third release of mission data, known as Early Data Release 3 (Gaia EDR3), astronomers have created a map of the entire sky that includes updated data on celestial objects and manages to capture the total brightness and color of stars in our galaxy.
Continue reading “This is Not a Photo of the Milky Way. It’s the Map of 1.8 Billion Stars From Gaia’s Major New Data Release”
In the past few decades, the study of exoplanets has grown by leaps and bounds, with 4296 confirmed discoveries in 3,188 systems and an additional 5,634 candidates awaiting confirmation. Because of this, scientists have been able to get a better idea about the number of potentially-habitable planets that could be out there. A popular target is stars like our own, which are known as G-type yellow dwarfs.
Recently, an international team of scientists (led by researchers from the NASA Ames Research Center) combined data from by the now-defunct Kepler Space Telescope and the European Space Agency’s (ESA) Gaia Observatory. What this revealed is that half of the Sun-like stars in our Universe could have rocky, potentially-habitable planets, the closest of which could be in our cosmic backyard!
Continue reading “Based on Kepler Data, There’s a 95% Chance of an Earth-Like Planet Within 20 Light-Years”
For decades, astronomers have been trying to understand why the Milky Way galaxy is warped the way it is. In recent years, astronomers have theorized that it could be our neighbors, the Magellanic Clouds, that are responsible for this phenomenon. According to this theory, these dwarf galaxies pull on the Milky Way’s dark matter, causing oscillations that pull on our galaxy’s supply of hydrogen gas.
However, according to new data from the European Space Agency’s (ESA) star-mapping Gaia Observatory, it is possible that this warp is the result of an ongoing collision with a smaller galaxy. These findings confirm that the warp in our galaxy is not static, but subject to change over time (aka. precession), and that this process is happening faster than anyone would have thought!
Continue reading “The Disk of the Milky Way is Warped Because it Already Collided With Another Galaxy”
Jupiter’s moon Europa continues to be a source of wonder and scientific intrigue. As one of the four Galilean Moons (so-named because of their founder, Galileo Galilee), Europa is one of Jupiter’s largest satellites and is considered one of the best bets for finding extraterrestrial life in the Solar System. And recently, it joined its cousins (Io and Callisto) in passing in front of a star.
This type of rare event (a stellar occultation) allows astronomers to conduct unique observations of a celestial body. In Europa’s case, the occultation took place in 2017 and allowed astronomers to make more precise measurements of Europa’s size, its position relative to Jupiter, and its true shape. All this was made possible by the ESA’s Gaia Observatory, which let astronomers know exactly when and where to look for the moon.
Continue reading “Thanks to Gaia, we Now Know Exactly How Big Europa is”
Despite the many advancements made in the field of astronomy, astronomers still struggle to get an accurate assessment of the Milky Way Galaxy. Because we are embedded in its disk, it is much more difficult to assess its size, structure, and extent – unlike galaxies located millions (or billions) of light-years away. Luckily, thanks to improved instruments and tireless efforts, progress is being made all the time.
For instance, a team of astronomers recently combined the latest data obtained by the ESA’s Gaia observatory with the infrared and optical observations of other telescopes to start mapping the bar-shaped collection of stars at the center of our Milky Way. This constitutes the first time in history that astronomers have been able to make direct measurements of this barred structure.
Continue reading “Gaia Mission is Mapping Out the Bar at the Center of the Milky Way”
During the early 1990s, NASA’s Pioneer 10 and 11 probes became the first robotic missions to venture beyond Neptune. In 2012 and 2018, the Voyager 1 and 2 missions went even farther by crossing the heliopause and entering interstellar space. Eventually, these probes may reach another star system, where their special cargo (the Pioneer Plaques and the Golden Records) could find their way into the hands of another species.
Which raises an important question: where might these spacecraft eventually wander? To address this, Coryn Bailer-Jones of the Max Planck Institute for Astronomy and Davide Farnocchia of NASA’s Jet Propulsion Laboratory recently conducted a study that examined which star systems the Voyager and Pioneer probes will likely encounter as they drift through the Milky Way over the next few million years…
Continue reading “Voyager and Pioneer’s Grand Tour of the Milky Way”