Hubble photographed a concentration of planets that move within the Milky Way and do not orbit a star
Avi Blizovsky, the scientist
Bodies the size of large planets may cruise through space without a shepherd in the M22 cluster region. The photo taken by Hubble is a close-up of the cluster
Astronomers have recently been able to observe what appears to be a small population of planet-sized objects moving through the galaxy with no connection to their parent star.
Using the Hubble Space Telescope, scientists have been able to locate what appear to be six objects, weighing only 80 times the mass of Earth, and these are the smallest independent objects seen so far. Smaller bodies observed were planets orbiting other suns.
The international team of researchers who used the magnification effect of the background stars calculated the size of the objects, and came to a conclusion about their nature, but stated that it was necessary to make additional observations in order to confirm the proposal. However, the scientific team was excited by the use of the experiment's method, which used a natural phenomenon known as microlenses, to succeed in photographing such dim objects.
"Hubble's sharpness allowed us to perform this new and special type of observation that successfully demonstrates our ability to see very small objects," said Kalish Shehu, a scientist at the Hubble Space Telescope Science Center and principal investigator in an article published in Nature. adding that: "This holds the potential for an in-depth study of dark and low-mass objects.
Microlensing occurs when a star in a bright background is obscured by a star in front of it, and the closer star amplifies the light of the distant star. Astronomers can estimate the mass of a nearby star based on the duration and strength of the boost.
Certain objects, too dim to observe directly, were discovered when they passed in front of bright stars in the massive central block of the Milky Way. Some of them appear to have no more than a quarter of the mass of the planet Jupiter.
If such free planets are indeed as small as the research estimates they are exactly? Orphan planets torn apart by the gravity of their parent stars? There are many of them in the universe. Astronomers estimate that about ten percent of the planets formed in star clusters are torn from the parent star. The cluster in question, M22, is about 8,500 light years from Earth.
Until now, microlensing has been used to discover light bodies in the disk and halo of our galaxy. But Hubble's exceptional visibility was needed to perform such a search in a globular star cluster.
In normal lensing events, background stars brighten and dim in a length of time that depends on the mass of the closer object. Since the events were shorter than the time intervals between Hubble's photographs, there is only a maximum estimate for the size of the objects - about a quarter of Jupiter's mass.
To retest the findings, Sahu and his colleagues plan to observe the heart of the globular cluster continuously for seven days. They expect to detect enough short microlensing events to more precisely measure the mass of the small objects. If it does confirm the current findings, the dim wanderers could provide an unexpected look at the process of star and planet formation. say the astronomers.
