BEIJING, Oct. 13 (Xinhua) — Astronomers have discovered thousands of other exoplanets since the first exoplanet was first discovered in 1992,media reported. In fact, they estimate that our Milky Way galaxy has about 40 billion planets. Therefore, it is natural to think that other galaxies will also have many planets, especially those that look a little similar to ours. But there is a problem with finding these planets.
M51 vortex galaxy.
From our earth, other galaxies are so far away that stars seem to be huddled in tiny areas. It’s hard to identify individual galaxies, let alone any influences on the surrounding planets. So the planets outside the Milky Way have managed to evade astronomers.
But recently, Rozan Di Stefano of the Harvard-Smithsonian Center for Astrophysics and several colleagues said they had found a candidate planet in the M51 vortex. The M51 vortex galaxy is located near the constellation Big Bear, about 23 million light-years from Earth. Named M51-ULS-1b, this extraterrestary may be slightly smaller than Saturn and orbits a twin galaxy at an orbit about ten times the distance between Earth and the sun.
Observations are possible because of a series of special conditions. The planet’s twin galaxies contain a neuter star or black hole that engulfs nearby stars at great speed. Inhalation of stardust releases a lot of energy, making the twin galaxy the brightest source of X-rays in the entire vortex galaxy. In fact, the X-ray brightness of the twin galaxies is one million times brighter than the total brightness of all wavelengths of sunlight.
But the source of these X-rays, black holes or neutre stars, is small. This means that Saturn’s large asteroid, which orbits a billion kilometers away, can completely block the X-ray source if it orbits exactly in a straight line with Earth and is directly in front of the X-ray source.
This particular phenomenon occurred on 20 September 2012. Fortunately, the Chandra X-ray Observatory also observed the phenomenon at the time. The X-ray source gradually disappeared to zero, and then gradually recovered, the entire star process of about 3 hours.
No one noticed at the time, because no one had searched the Chandra Observatory’s data set for such a short change. But then, when Di Stafano and his colleagues saw the data, they immediately saw the end.
There are many reasons why X-ray sources darken in this way. One is the existence of another small star, such as a white dwarf, blocking the X-ray source. But the team believes that M51-ULS-1b is unlikely to be a white dwarf or any other type of star because the twin galaxy has not existed long enough for such objects to evolve near it.
Another possible explanation is natural changes, i.e. the sudden interruption of matter that may have fallen into a black hole or neutrogen star. Di Stafano and his colleagues say that if this is the case, brightness changes will be characterized by changes in the frequency of high-energy light that change faster than low-energy light frequencies and in different ways.
But in this phenomenon observed by the Chandra X-ray Observatory, all light frequencies disappear at the same time and recover at the same time, which is more like an erosion phenomenon. “Approximate symmetry and have a typical star shape, where the light source is the size of the star object, ” they said.
Now that the first planetary candidates for other galaxies have emerged, Di Stafano and his colleagues believe that other exoplanets should also be discovered soon. The team searched only part of the X-ray data from the Chandra X-ray Observatory to find the new planet’s candidate.
There are many sources of data. “These files contain enough data for us to do more research,” the team said. “At the same time, new data is accumulating.
So M51-ULS-1b may be the first planetary candidate we’ve found in other galaxies, but it won’t be the last. (Uniform)