Proxima Centauri is the closest star to earth other than our sun. It is a companion star to the binary star system Alpha Centauri A and B, and is about 4.22 light-years from earth.
A team of astronomers has discovered a planet called Proxima Centauri d orbiting the nearby star. It’s thought to be smaller than the earth and might have oceans of liquid water.
Alpha Centauri
The closest star to earth other than the sun is Alpha Centauri, a triple star system that contains two very bright stars and one fainter red dwarf. The system is 4.2 light-years away, and its two main stars are Alpha Centauri A and Alpha Centauri B, also known as the AB pair. The third star is Proxima Centauri, a red dwarf that is about 0.3 light-years from the other two.
Alpha Centauri A and B are both incredibly similar to our own Sun, in age, spectral type, size, and color. The difference is that Alpha Centauri B is much smaller, dimmer, and closer to the center of the system than our own Sun.
This makes the pair a natural place to look for exoplanets, which can orbit stars in close proximity like Alpha Centauri A and B, but are often harder to spot due to their spectral lines. So astronomers have spent years studying the pair and their wobbles in an attempt to detect planets.
For a long time, scientists could only detect planetary orbits by measuring the radial velocity of the stars — the rate at which they change their positions in relation to each other. But that method can be hard to get right, especially when stars move a lot.
A better approach is to measure the angular momentum of a star, which lets astronomers see if it’s moving faster or slower than other stars nearby. This has been done before, but astronomers weren’t getting any useful results, so Beichman and his team have come up with a new way to do it.
The new technique uses an instrument called the Near-infrared Exoplanet Array Recorder (NEAR), which blots out starlight at 10 microns, a wavelength too narrow to be absorbed by Earth’s atmosphere but too long to scatter. It’s designed to sweep in and out of the light of each star every tenth of a second, using data from both stars to help calibrate its focus.
Scientists hope that NEAR will help them find the exoplanets they’ve been looking for. But even if it finds nothing, the team will still have the data to use for future searches.
Proxima Centauri
The closest star to earth other than the sun is Proxima Centauri, located in the southern constellation of Centaurus. It is a red dwarf, and is classified as a class M5 star. It has a luminosity that is about 2.5% of the Sun’s.
The star is very active and has massive flares that can reach temperatures of 27 million K, high enough to emit X-rays. These massive flares have been observed with several X-ray space telescopes, including EXOSAT and ROSAT.
There is a lot we don’t know about this star, but we do have evidence that it hosts one planet. This planet is roughly Earth-sized, orbiting within the star’s habitable zone (HZ).
It completes one orbit every 11 Earth days, placing it in the range where liquid water could exist on its surface. It’s also very close to the star, so it would get a lot of light and heat from the star.
Researchers say this makes the planet very likely to have a thick hydrogen and helium atmosphere. This type of atmosphere can trap heat, keeping it from warming up the planet.
Another interesting thing about this planet is that it orbits a flare star, which means it has to contend with massive flares from the star. These flares can be dangerous to life on the planet.
Astronomers are hoping that this new planet, which is called Proxima c, will be able to survive the star’s radiation. In the meantime, they will continue observing the star to look for more planets around it and to see if it can support life in the future.
The discovery of this planet is a major breakthrough in our quest to find other exoplanets. We’ve previously identified three low-mass planets in this system, and this new detection puts us closer to finding a fifth one.
The new discovery is a great boost for the search for exoplanets, and it shows that the technology we have now can help us detect even the most distant planets in our galaxy. We hope this is the first of many discoveries.
Barnard’s Star
Barnard’s Star is a red dwarf, meaning it has only a fraction of the mass of our Sun and is very hot. It shines via thermonuclear fusion, changing light elements into more heavy ones and releasing immense amounts of energy. It is a member of the main sequence, meaning it will eventually burn out and become a blue dwarf or a white dwarf.
Barnard’s Star is a bright, dim, and extremely close star to Earth. It is located about 6.5 light-years from our sun, and if it were seen directly it would appear as a first-magnitude star in the constellation Ophiuchus (the Unicorn).
In 1963 Peter van de Kamp, of Swarthmore College, published a paper claiming to have detected an exoplanet orbiting the star. He used a technique called astrometry to measure how the star moved and found that it wobbled in a characteristic way, a sign that an extraterrestrial planet was tugging on it.
However, other astronomers were skeptical of the findings and a number of attempts to detect planets around the star failed to reveal any. Later, it was proposed as a target for Project Daedalus, a study by the British Interplanetary Society that sought to design an unmanned space probe that could reach Barnard’s Star in a human lifetime.
Since the 1960s, a large number of exoplanets have been discovered by looking for signs of periodic Doppler shifts in the frequency of starlight, a signal that can be interpreted as a planet’s gravitational tug on its host star. In 2015, a team of astronomers saw some of these signals and began a very detailed investigation into Barnard’s Star.
After several years of careful analysis, they announced in November 2018 that they had found a super-Earth orbiting Barnard’s Star. It had a mass of 2.3 times that of our Earth, and orbited its parent star every 233 days.
The discovery of this super-Earth was a real surprise for the astronomy community and is one of the most important exoplanet discoveries in history. The discovery of a super-Earth around Barnard’s Star may help scientists understand how to find more habitable planets beyond our solar system, which is already home to the largest collection of planets.
Ross 248
The closest star to Earth other than the Sun is Ross 248, located in the Constellation Andromeda. It is a red dwarf with a spectral type of M4 V. It has 15% of the mass of the Sun and only 21% of its diameter.
It is too faint to see with the naked eye, but it is a flare star that occasionally increases in luminosity. It was discovered in 1925 by Frank Elmore Ross, who first reported it in his “Second List of New Proper-Motion Stars,” Astronomical Journal.
As a red dwarf, it emits most of its energy in infrared light. This could explain why a planet around this star would not be able to support life, as it would not be able to absorb sunlight and convert it into energy on its surface.
Another interesting aspect of this star is that it doesn’t follow a straight path as it orbits the galactic plane. This wobble is likely caused by the gravity of one or more large planets that orbit it.
Despite its close proximity to the Sun, Ross 248 is a cool and dim red dwarf with a spectral type that is similar to Proxima Centauri (M5.5 or 4.9 Ve). It has about 12 percent of the mass of the Sun, seven percent of its diameter, but 11/100,000th of its luminosity.
The spectral type of this star means that it has a low temperature and is therefore very unlikely to have liquid water on its surface. If it did have liquid water, it would be very close to its parent star, so that it would be very difficult for us to detect.
If we did find a planet around Ross 248, it would be much larger than our Moon. It would also be much farther from the star than Mercury is from the Sun.
This would mean that it could be millions of kilometers away, which is a great distance to travel using current technology. If a spacecraft were to go this far, it would be thousands of years before it came back.