What's more, the view from that Earth-like planet as its giant neighbor moves past would be unlike anything it is possible to view in our own night skies on Earth, according to new research led by Stephen Kane, associate professor of planetary astrophysics at UC Riverside.
The research was carried out on planets in a planetary system called HR 5183, which is about 103 light years away in the constellation of Virgo. It was there that an eccentric giant planet was discovered earlier this year.
Normally, planets orbit their stars on a trajectory that is more or less circular. Astronomers believe large planets in stable, circular orbits around our sun, like Jupiter, shield us from space objects that would otherwise slam into Earth.
Questioning this assumption, Kane and Caltech astronomer Sarah Blunt tested the stability of an Earth-like planet in the HR 5183 solar system. Their modeling work is documented in a paper newly published in the Astronomical Journal .
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, …
NASA Chief Keeps Saying 'Pluto Is a Planet' Because It's a Complex, Amazing World | Space
The long-standing debate over Pluto's planethood recently got a public boost from NASA Administrator Jim Bridenstine, who said the world should definitely be a planet.
"I'm here to tell you, as the NASA administrator, I believe Pluto is a planet ," Bridenstine said to applause from the audience as the conference opened to public attendance.
* * *
NASA Administrator Jim Bridenstine spoke last month at the International Astronautical Congress, where he said that Pluto ought to be considered a planet.
The agency head made similar comments about Pluto in late August. But despite the object's complex characteristics, by the official definition of the International Astronomical Union, which oversees all planetary naming conventions, Pluto is not a planet.
In 2006, a time when many other worlds of Pluto's size were being discovered around the solar system, the body was reclassified as a dwarf planet. The status change came out of a controversial 2006 vote by scientists, with which New Horizons principal investigator Alan Stern and others do not agree .
'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.
While you're here, how about this:
It Seems Impossible, But Somehow This Planet Survived its Star's Red Giant Phase - Universe
Astronomers working with TESS (Transiting Exoplanet Survey Satellite) data have found a planet where it shouldn't be: in the space recently filled by its host star when it was a red giant.
TESS uses Asteroseismology to examine stars. It measures the tiny oscillations in a star that gives clues to its interior structure. These clues are hidden from other types of observations, like brightness and surface temperature. In a new published study, the authors examined two red-giant stars: HD 212771 and HD 203949. These are the first asteroseismology studies of stars that are known to host planets.
The title of the paper is " TESS Asteroseismology of the known red-giant host stars HD 212771 and 203949 ." The lead author of the paper is Tiago Campante, from the University of Porto, Portugal. In a press release , Campante explained how TESS's power helped the authors study these stars: "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 test-bed for studies of the evolution of planetary systems."
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.
* * *
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.
There's Something Strange Going On Inside Neptune | Space
The storm was something of a surprise. In the southern hemisphere there was a swirling, counter-clockwise wind of up to 1,500 mph (2,414 km/h) — the strongest ever recorded. Astronomers called it the Great Dark Spot, and while it had gone by the time the Hubble Space Telescope looked at the planet five years later, they were keen to learn why the winds were so extreme.
* * *
They were also perplexed by another issue: Voyager 2 revealed that Neptune is warmer than Uranus , despite being farther from the sun. As physicist Brian Cox discussed in his BBC documentary, The Planets : "The source of this extra heat remains a mystery." But does that mean we have a double-puzzle on our hands, and can one mystery help to explain the other in some way?
Before we begin to address the two issues at hand, we must first look at what is actually meant by "warmer". Since Neptune is a gas giant , we cannot test the globally average temperature at ground level in the way that we could on Earth's solid surface. Instead, with Neptune's core likely to be small, temperature measurements must be taken at an altitude. Trouble is, which one?
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.
No comments:
Post a Comment