An international group of astronomers has discovered two exoplanets orbiting a nearby dwarf star known as TOI-2095, which is 137 light-years from the sun.
Using NASA's Transiting Exoplanet Survey Satellite (TESS), an international team of astronomers discovered the two exoplanets orbiting the dwarf star at short orbital periods.
According to the results published in the journal arXiv, the new celestial bodies, called TOI-2095 b and TOI-2095 c, belong to the category of "super-Earths". Their sizes range from 1 to 4 Earth radii.
The TESS satellite is surveying about 200,000 of the brightest stars near the sun with the aim of searching for transiting exoplanets, ranging from small rocky worlds to gas giants.
To date, 6,400 exoplanet candidates (TESS Objects of Interest, or TOI) have been identified, of which 330 have been confirmed so far.
Now, a team of astronomers led by Felipe Morgas of the University of La Laguna, Spain, reports that two exoplanets detected by TESS have been confirmed.
By making optical observations and radial velocity measurements, they found that the transit signals in TOI-2095's light curve are planetary in nature.
According to the study, the TOI-2095 b planet is about 25% larger than Earth and has an orbit of 17.66 days. It is closest to its host star, at a distance of about 0.1 astronomical unit (AU), and has an equilibrium temperature of 73.85 degrees Celsius (347 K), while Its mass is estimated to not exceed 4.1 Earth masses.
As for the second planet in the TOI-2095 c system, it has a radius of about 1.33 Earth's radii, and it orbits its host every 28.17 days, at a distance of about 0.137 astronomical units from it. TOI-2095 c has an equilibrium temperature of approximately 23.85 °C (297 K), and its maximum mass has been calculated to be 7.4 Earth masses.
The host star, TOI-2095, is about 56% smaller in mass than the Sun. It is a red dwarf star of spectral class M2.5 V, has an effective temperature of 3,485 °C (3,759 K), and metallicity (abundances of iron and hydrogen) at -0.24. The star is estimated to be at least a billion years old.
The paper's authors note that the newly discovered exoplanets are close to the inner edge of TOI-2095's habitable zone and that their parameters make them attractive targets for further follow-up observations.
Astronomers find evidence of two planets forming in a distant star system
Astronomers believe they have found evidence of two planets forming in a young star system about 200 light-years from Earth.
Scientists detected two shadows in a disk of gas and dust surrounding TW Hydrae, a red dwarf star less than 10 million years old. Two smaller disks are believed to lie within this star system.
Red dwarfs are the smallest, less than half the mass of the Sun, and the most common type of star in the Milky Way.
The two discs are believed to be evidence of a pair of planets in the making. Scientists said the findings, published in the Astrophysical Journal, give insight into how Earth and the other planets in the solar system looked when they were forming some 4.6 billion years ago.
Scientists analyzed data captured by the Hubble Space Telescope and found two shadows in the disk of gas and dust in the TW Hydrae star system.
The first shadow was spotted in observations from 2017, while the second shadow appeared four years later, baffling astronomers.
The scientists suggested that there were two deviant discs casting their shadows, and they were very close to each other in the previous observation, so the scientists missed their observation. And with the passage of time they now separated and split into two shadows. "We've never seen this before on a protoplanetary disk. It makes the system much more complex than we originally thought," said Dr. John Debbs, an astronomer at the Space Telescope Science Institute in the United States, who is also the principal investigator on the study.
The simplest explanation is that the skewed disks are likely caused by the gravitational pull of two planets in slightly different orbital planes. Hubble is assembling a comprehensive view of the system's structure.
Scientists pointed out that the TW Hydrae system gives them an opportunity to see what our solar system was like during its formative years.
Scientists said that the suspected planets are located in an area close to the distance between Jupiter and the sun, and the shadows complete one cycle around the star approximately every 15 years.
Scientists added that the outer disk also contains a strange gap at twice the average distance of Pluto from the sun, which may be possible evidence of the existence of a third planet in the star system.
However, they added, it would be difficult to detect any inner planets because their light would be lost in the star's glow and the surrounding dust would dim the reflected light.
Study author Rebecca Nealon, Assistant Professor of Physics at the University of Warwick, explained: "The shifting shadows in TW Hydrae present a particular challenge to theorists. But our models were able to show that the most likely explanation is these two tilted disks casting shifting shadows. It is possible that the TW Hydrae will hide Two planets are in perverse orbits, thus perpetuating the mystery of this planet-forming disk."
What is the size of supermassive black holes? Animation from NASA providing the answer
Supermassive black holes are at the center of all large galaxies, including the Milky Way. These cosmic bodies weigh between 100,000 and tens of billions of times the mass of the sun.
And if you've ever wondered how big these celestial bodies are, a new animation from NASA may give you the answer you're looking for.
A black hole is a region of space where the force of gravity is so strong that nothing, not even light, can escape. And the gravitational force is so strong because the material has been compressed into a small space. These astronomical objects can be formed due to dying stars. The largest black holes in the universe are called supermassive (or supermassive) black holes.
More than 100 supermassive black holes have been confirmed. And in 2019, astronomers took the first image of giant black holes at the center of M87 and the Milky Way. They revealed a bright ring of hot gas orbiting a circular region of darkness.
Direct measurements, many of them made with the help of the Hubble Space Telescope, "confirm the existence of more than 100 supermassive black holes," said Jeremy Schnittman, a theoretical researcher at NASA's Goddard Space Flight Center.
"How do supermassive black holes become so big? When galaxies collide, their central black holes may eventually merge together," Schnittmann added.
A new animation released by NASA shows 10 supermassive black holes lurking at the center of their host galaxies, measured by the sizes of their shadows. The clip also contains a black hole in the Milky Way.
Starting with the sun, the images in the video are steadily zoomed out to compare the sizes of black holes to different objects in the solar system.
The black hole in the Milky Way is called Sagittarius A*, and it weighs 4.3 million suns, based on long-term tracking of stars in orbit around it. The diameter of its shadow extends about half the diameter of Mercury's orbit in our solar system.
In the video, as well as Sagittarius A*, a dwarf galaxy dubbed J1601 + 3113, which hosts a black hole with a mass of 100,000 suns, is shown.
The clip shows two monstrous black holes in the galaxy known as NGC 7727, located about 1,600 light-years away. One of the two black holes weighs about 6 million solar masses, and the other weighs more than 150 million suns.
Astronomers expect the two black holes to merge within the next 250 million years.
The video ends with TON 618, which is among the most distant and massive black holes that astronomers have direct measurements of.
NASA said: "This giant contains more than 60 billion solar masses, and boasts shadows so large that a ray of light could take weeks to traverse it."
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