(CNN) Just 11 light years from earth is the GJ 15 A star system with two planets orbiting a red-dwarf star. This makes it the closest solar system to Earth that contains multiple planets.
While you're here, how about this:
It's an asteroid! No, it's the new smallest dwarf planet in our solar system - CNN
(CNN) A large asteroid could be reclassified as a dwarf planet -- which could make it the smallest in the solar system -- after new research revealed its shape, astronomers said on Monday.
How Did That Planet Get There? TESS Investigates a Planetary Mystery | Digital Trends
NASA’s planet-hunting satellite TESS, or Transiting Exoplanet Survey Satellite, has made another intriguing discovery. This time, it’s located a planet somewhere where it shouldn’t be, right in the middle of a zone in which any planet should have been annihilated by its star.
The star HD 203949 is located 257 light-years away and is a K2-type giant star, slightly cooler than our sun. Traveling around this star is a large planet, HD 203949b, which is 8.2 times the mass of Jupiter and in a 184-day circular orbit.
So far, so typical. But there’s something odd about HD 203949b because it should have been engulfed by its star long ago. The boundaries of a star, called its envelope, expand and contract over time. When the giant star HD 203949 was younger in its red giant phase, its envelope should have covered the planet and destroyed it — and yet the planet is still there.
'Dirty' Collisions Shed Light on Planet Formation | Space
Planetary models are incredibly complex, requiring scientists to account for everything that happens to a growing planet on timescales spanning a few days to millions of years. In the past, astronomers would simplify their models of colliding objects by assuming that all of the material from both the impactor and its target perfectly merged into a single object — an unrealistic expectation, since at least some pieces would most likely be flung into space and lost. But because computers of the past were less powerful than those today, scientists were forced into the simplification.
In the past decade, however, improvements in computational power have allowed researchers to begin studying more-realistic collision scenarios. Now, scientists can model so-called hit-and-run collisions , where two bodies scraped each other in passing, or even the total annihilation that could occur when two planetary embryos slammed together. These imperfect "dirty collisions" not only affect how large planets grow to be but also help to explain their orbits.
This may worth something:
Spot six planets in the sky this week: Mercury, Mars, Uranus and more | New Scientist
THE coming week is a great time to look for planets. A new moon on 28 October means no moonlight and, with the exception of Neptune , every planet is visible at some point in the coming days. Even distant Uranus, which at 8 pm GMT on 27 October will be a mere 2.8 billion kilometres away.
Venus is the easiest to find, with an apparent magnitude of -4.6. In the magnitude scale, objects with lower numbers are brighter. It is close to the sun, …
'Impossible' exoplanet and an alternate planet-formation theory | Space | EarthSky
The discovery of exoplanet GJ 3512b – a planet “too big for its star” – adds fuel to the competition between 2 theoretical models of how planets form. It suggests many more Jupiter-like planets are waiting to be found, orbiting nearby sunlike stars.
Notice the spiral structure here? This isn’t a galaxy; it’s a computer simulation of a newly forming solar system. It’s part of the disk instability model of how planets form, a model that’s been less accepted by astronomers – until now. A new discovery suggests this model may be correct. If so, Jupiter-like worlds may be common around nearby sunlike stars. Image via astronomical theorist Alan Boss/ Carnegie Science .
Boss’s new work is supported by a September 27, 2019, paper, published in the peer-reviewed journal Science , reporting on the discovery of a new exoplanet labeled GJ 3512b . This confirmed, massive, Jupiter-like planet orbits a very low-mass red dwarf star. And thus this planet – sometimes called the planet that shouldn’t exist – belies the previously most-popular theory of planetary formation, which had suggested it was impossible for such a massive planet to form around such a small star. From the September 27 paper:
'Improbable Planet' Somehow Survives Being Swallowed by Red Giant Star | Space
Scientists have discovered a "survivalist" planet that shouldn't exist orbiting a pulsating star.
Using astroseismology data from NASA's Transiting Exoplanet Survey Satellite , or TESS, a team of researchers studying the red giant stars HD 212771 and HD 203949 detected oscillations, which are "gentle pulsations at the surfaces of stars," lead author Tiago Campante of the Instituto de Astrofísica e Ciências do Espaço (IA) and Faculdade de Ciências da Universidade do Porto, told Space.com. This is actually the first time that oscillations have been found by TESS in stars that host exoplanets.
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" TESS observations are precise enough to allow measuring the gentle pulsations at the surfaces of stars. These two fairly evolved stars also host planets, providing the ideal testbed for studies of the evolution of planetary systems," Campante said in a statement .
Lessons from scorching hot weirdo-planets
Illustration of a hot Jupiter planet in the Messier 67 star cluster. Hot Jupiters are so named because of their close proximity — usually just a few million miles — to their star, which drives up temperatures and can puff out the planets.
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Hot Jupiters were the first kind of exoplanet found. A quarter-century later, they still perplex and captivate — and their origins hold lessons about planet formation in general.
In 1995, after years of effort, astronomers made an announcement: They'd found the first planet circling a sun-like star outside our solar system. But that planet, 51 Pegasi b, was in a quite unexpected place — it appeared to be just around 4.8 million miles away from its home star and able to dash around the star in just over four Earth-days. Our innermost planet, Mercury, by comparison, is 28.6 million miles away from the sun at its closest approach and orbits it every 88 days.
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