Scientists have discovered a lone orphan planet wandering through the Milky Way with no parent star to guide it – a “rogue” planet, with no day to live with, day or night in the infinite darkness of the Gurudwara siblings. Is stuck.
It is possible that our galaxy is full of them Rogue planet, But this is especially unusual for a specific reason: it is the smallest to date – even smaller than Earth – with the same mass as Mars.
Scientists have discovered more than 4,000 “extrasolar” planets, also called exoplanets, Are the planets that orbit a star other than the sun. Many exoplanets – for example, one where it Liquid iron rain – The planets in our solar system do not match, but they all have one thing in common: they orbit all the stars.
But just a few years ago, astronomers in Poland discovered evidence of a star seriously missing non-floating planets in the Milky Way galaxy. In one New study, The same astronomers have found the smallest such planet ever.
John Scowern / Astronomical Observatory, University of Versailles
Exoplanets are difficult to find, usually just by looking at the light from their host stars. Because free-floating planets have no original star and no radiation, astronomers have to take a different approach to find them.
Diseases are observed using planetary gravitational microlensing, the result of Albert Einstein’s theory of general relativity. In this case, the planet’s gravity (mirror) acts as a kind of magnifying glass, behind which it is able to divert the light of a bright star (source) so that an observer can detect its presence on Earth. .
A post-doctoral scholar at the California Institute of Technology, lead author Dr. News released On Thursday. “The chances of seeing microlensing are slim because the three objects – the source, the lens and the observer – must be almost completely identical. If we only saw one source star, we would have to wait about 1 million years for the source to be microlensed. ”
In search of these events, researchers are monitoring hundreds of millions of stars at the center of the galaxy, which provide the greatest potential for microlensing.
The Optical Gravitational Lens Experiment Survey, led by astronomers at the University of Warsaw, is one of the largest and longest sky surveys in the last 28 years. Currently using a telescope at the Las Campanas Observatory in Chile, astronomers look at the center of the galaxy in the clear night in search of changes in the brightness of the stars.
Because the technique relies solely on the brightness of the source, not the lens, it allows astronomers to detect faint or dark objects – such as rogue planets.
John Scowern / Astronomical Observatory, University of Versailles
Measuring the duration of such an event, in addition to the shape of its light curve, can provide an estimate of the mass of the object that astronomers are looking for. While most of the programs viewed, by the stars, last for several days, the smaller planets provide only a few hours’ window.
In this case, OGLE-2016-BLG-1928, the smallest microlensing event ever recorded lasted only 42 minutes. Based on the incident, astronomers estimated that the planet had a mass similar to Mars and found it to be rogue.
Co-author from the University of Warsaw Astronomy Supervisor, Dr. “When we first saw the event, it was clear that it must have been caused by something very small,” said Radosla Poleski. “If the lenses were orbiting a star, we can detect its existence. In this case we can star the planet within 8 household units (the astronomical unit is the distance between the earth and the sun). . “
It is not entirely clear why these rogue planets have no original stars, but scientists do not think the planets had any say in the matter. Instead, they will actually form “normal” planets – only to be pulled out of their ecliptic systems after discussions with other planets about gravity.
NASA is currently building the Nancy Grace Roman Space Telescope, which is scheduled to begin operations in mid-2020. Studying these free-floating planets can help astronomers better understand the volatile history of young planetary systems – including our own solar system.
