51 Pegasi b

There is a far away world.

It orbits a bright star. This world is very hot. It is a giant ball of gas.

It is much closer to its star than we are to our Sun. Because it is so close, it orbits in just four days. People found traces of water in its air. Its name is Dimidium. This name means "half." It is half the mass of a giant planet called Jupiter. This big discovery won a special prize for science.

There is a far away world called Dimidium.

It orbits a star in the Pegasus constellation. This star is like our Sun. In 1995, two scientists found this planet. They used a tool to see how the star moved. The planet's pull made the star move slightly. This was a big breakthrough for science. The scientists even won a Nobel Prize for it.

Dimidium is a gas giant. This means it is a huge ball of gas. It is much closer to its star than Mercury is to our Sun. Because it is so close, it orbits in just four days. This planet is a hot Jupiter. That is a name for big, hot planets. It is about half the mass of Jupiter. The name Dimidium means "half" in Latin.

The planet is very hot. Its atmosphere is thick and puffed up. Scientists found traces of water in its air. One side of the planet always faces its star. This happens because the planet is tidally locked. That means it does not spin like Earth does.

There is a special world far away in the Pegasus constellation.

Its official name is Dimidium. It orbits a star called 51 Pegasi. This star is a main-sequence star, which means it is like our Sun. Dimidium is very important to science. It was the first planet found orbiting a star like ours. This discovery changed how we study space.

Scientists found this planet by watching the star carefully. They used a tool called a spectrograph. This tool looks at light from the star. The planet has a gravitational effect on its star. This pull causes the star to move slightly. The star's speed changes by about 70 metres per second. These small changes happen because the planet is only 7 million kilometres away.

Two scientists named Michel Mayor and Didier Queloz found the planet. They worked at the University of Geneva. They shared their news on October 6, 1995. They used a telescope in France to see the star. Another team at the Lick Observatory in California confirmed it one week later. Because of this great work, they won the Nobel Prize in Physics in 2019.

Dimidium is a gas giant. It is a type of planet called a hot Jupiter. This means it is huge and very hot. The planet has about half the mass of Jupiter. It is about 150 times the mass of Earth. It orbits its star very fast. One full trip around the star takes only four days. This is much closer than Mercury is to our Sun.

The planet is a very strange place. Its atmosphere is thick and puffed up from the heat. Scientists even found traces of water in the air. One side of the planet always faces its star. This is called being tidally locked. The gases might be so hot that the planet glows red. It might even have clouds made of silicates.

Dimidium is a remarkable extrasolar planet located in the constellation Pegasus.

It orbits a Sun-like star known as 51 Pegasi. This planet is a major milestone in astronomy. It was the first planet ever discovered orbiting a main-sequence star. Because of this, it serves as the prototype for a specific class of worlds. Scientists call these worlds "hot Jupiters." This category includes giant planets that orbit very close to their stars.

Astronomers found Dimidium using a technique called the radial velocity method. This process involves using a sensitive instrument called a spectrograph. The spectrograph looks at the spectral lines of the host star. As the planet orbits, its gravity pulls on the star. This gravitational pull causes the star to move slightly back and forth. These movements create small, regular velocity changes in the star's light. For 51 Pegasi b, these changes were about 70 metres per second. These shifts happen because the planet is only 7 million kilometres from its star.

Dimidium is classified as a gas giant. It has a minimum mass that is about half that of Jupiter. This mass is roughly 150 times larger than the mass of Earth. The planet orbits its star incredibly fast. It completes one full orbit in only about four days. This orbit is much closer to the star than Mercury is to our Sun. The planet is also tidally locked to its host star. This means it always shows the same face to the star.

The discovery of this planet was a massive breakthrough. Michel Mayor and Didier Queloz announced the find on October 6, 1995. They worked at the University of Geneva. They used the ELODIE spectrograph at the Observatoire de Haute-Provence in France. Within one week, a team at the Lick Observatory in California confirmed the discovery. This work was so important that Mayor and Queloz won the Nobel Prize in Physics in 2019.

When it was first found, Dimidium was an anomaly. It did not fit the existing theories of how planets form. Scientists did not expect a huge world to exist so close to a star. Since then, researchers have found other hot Jupiters, such as those near 55 Cancri. This has led astronomers to study orbital migration to explain these systems. The planet is massive enough that its star's solar wind cannot blow its atmosphere away. In 2017, scientists even found traces of water in its atmosphere.

The physical environment of Dimidium is extreme. The planet is superheated by its nearby star. This heat causes its atmosphere to puff up into a thick, tenuous layer. Because of this, the planet might have a larger radius than Jupiter. Beneath this layer, the gases may be so hot that the planet glows red. The atmosphere might also contain clouds made of silicates. If the planet has a Bond albedo of 0.1, its temperature would be very high.

Researchers continue to study the planet's light to learn more. A 2015 study suggested they could detect the planet in visible light. This would have helped determine its true mass and size. However, later studies in 2020 could not replicate that result. Recent work suggests the planet has a low albedo, which is how much light it reflects. Current estimates suggest the planet has a radius around 1.2 Jupiter radii. Studying these details helps us understand the diversity of worlds in our galaxy.