Exoplanets

[Drone]

Gemini made direct images of two planetary systems:

HR 4796A with dusty ring

HR 8799 with 3 planets (located 130 ly away from us)

 

[Drone]

Astronomers using Kepler Space Telescope have discovered three super-Earth exoplanets orbiting a star called EPIC 201367065.

EPIC 201367065 is a red M-dwarf ~ half the size and mass of our Sun. It lies at a distance of 147 ly.
The three exoplanets are 2.1, 1.7 and 1.5 times the size of Earth.
In order from closest to farthest to their star, the exoplanets receive 10.5, 3.2 and 1.4 times the light intensity of Earth.


******************************

At least two planets larger than Earth likely lurk in the dark depths of space far beyond Pluto, just waiting to be discovered.

The potential undiscovered worlds would be more massive than Earth and would lie so far away that they'd be very difficult, if not impossible, to spot with current instruments. 2012 VP113 and Sedna are two known denizens of the inner Oort Cloud. Their orbits are consistent with the continued presence of a big "perturber" [perhaps a planet 10 times more massive than Earth that lies 250 AU from the sun].

 

[VulkanBros]

Interesting indeed.....

 

[Drone]

Planet J1407b is much larger than Jupiter or Saturn, and its ring system is roughly 200 times larger than Saturn's rings are today. This gigantic ring system is eclipsing the young sun-like star J1407.

Astronomers found ancient star system Kepler-444. It's 11.2 billion years old and hosts five planets smaller than Earth, with sizes varying between those of Mercury and Venus.

 

[Drone]

Astronomers Discover New Super-Jupiter Exoplanet Kepler-432b

It's ~ 2850 ly away. It's one of the most dense and massive planets known so far. The planet has a mass 5.84 times that of Jupiter and orbits its parent star, the red giant Kepler-432, in 52 Earth days.

The host star, Kepler-432, has already exhausted the nuclear fuel in its core and is gradually expanding. Its radius is already 4 times that of our Sun and it will get even larger in the future. The orbit brings the planet incredibly close to Kepler-432 at some times and much farther away at others, thus creating enormous temperature differences over the course of the planet's year (500 C during the winter season and 1000 C in the short summer season).

The days of Kepler-432b are numbered. In < 200 million years, the planet will be swallowed by its continually expanding host star.



Another red giant orbited by a Jupiter-mass planet called Kepler-91b on an orbit of 6.2 days was discovered in 2013.




250 Years of Planetary Detection in 60 S

 

[Drone]

Astronomers Create Habitability Index for Transiting Exoplanets

The habitability of an exoplanet is traditionally assessed by comparing a planet's semi-major axis to the location of its parent star's ‘habitable zone’ – the shell around a star for which terrestrial planets can possess liquid surface water.

In creating it, the scientists factored in estimates of a planet's rockiness, rocky planets being the more Earth-like.

They also accounted for a phenomenon called ‘eccentricity-albedo degeneracy,’ which comments on a sort of balancing act between the a planet's albedo – the energy reflected back to space from its surface – and the circularity of its orbit, which affects how much energy it receives from its host star.

A life-friendly energy equilibrium for a planet near the inner edge of the habitable zone – in danger of being too hot for life, would be a higher albedo, to cool the world by reflecting some of that heat into space. Conversely, a planet near the cool outer edge of the habitable zone would perhaps need a higher level of orbital eccentricity to provide the energy needed for life.

 

[Drone]

KIC 8462852, located 1480 ly from us, produced a series of bizarre light fluctuations, scientists cannot explain. A theory suggest that a megastructure is obscuring the light from it.

Over the duration of the Kepler mission, KIC 8462852 was observed to undergo irregularly shaped, aperiodic dips in flux down to below the 20% level. The dipping activity can last for between 5 and 80 days.

 

[Drone]

Earth came early to the party in the evolving universe. According to a new theoretical study, when our solar system was born 4.6 billion years ago only 8% of the potentially habitable planets that will ever form in the universe existed. And, the party won't be over when the sun burns out in another 6 billion years. The bulk of those planets - 92% - have yet to be born.

There is enough remaining material [after the Big Bang] to produce even more planets in the future, in the Milky Way and beyond.

Based on the survey, scientists predict that there should be 1 billion Earth-sized worlds in the Milky Way galaxy at present, a good portion of them presumed to be rocky. That estimate skyrockets when you include the other 100 billion galaxies in the observable universe.

The observational evidence for the Big Bang and cosmic evolution, encoded in light and other electromagnetic radiation, will be all but erased away 1 trillion years from now due to the runaway expansion of space. Any far-future civilizations that might arise will be largely clueless as to how or if the universe began and evolved.

The last star isn't expected to burn out until 100 trillion years from now. That's plenty of time for literally anything to happen on the planet landscape.

 

[McSteel]

So, we're basically enjoying exclusive early-access universe...
No wonder physics is struggling to expose and make sense of the underlying engine - the game is still in development

I wonder what form will late-development intelligent life take... Wish we could transcend mortality and distances and witness it first-hand.

 

[Drone]

I'm not fond of anthropic principle but it does seem that we live in some 'special' era. Yeah, it's some early-access beta version but I don't think that engine will be changed maybe some bugfixes and stuff.

In the meanwhile distant worlds still amaze me:

A team of astronomers at the Leibniz Institute for Astrophysics Potsdam, Germany, has created a video that shows the evolution of stellar spots on the red giant star XX Triangulum (aka HD 12545) It's an active K0 giant star located ~ 1500 ly away toward the constellation Triangulum. This star is approximately 10 times larger and twice as massive as the Sun.


And two new worlds:

A team of U.S. astronomers has made a surprising discovery using data collected by NASA's Kepler/K2 mission: a star called WASP-47, a previously known hot Jupiter exoplanet host, also hosts two additional exoplanets – a Neptune-sized outer planet and a super-Earth inner companion.

WASP-47 also known as 2MASS J22044873-1201079, is a G-type main sequence star, slightly smaller and cooler than our Sun at a distance of 652 ly.

One of the newfound exoplanets, WASP-47d, is about the size of Neptune and orbits the star in about 9 days.

The second newly-discovered planet, WASP-47e, is a so-called super-Earth that whips around the star in a mere 19 hours.

The hot Jupiter WASP-47b orbits its parent star every 4.16 days.

 

[Drone]

Astronomers announced today that they have spotted a large, rocky object disintegrating in its death spiral around a distant white dwarf star.

The object is in an orbit about 520,000 miles from the white dwarf (about twice the distance from the Earth to the Moon). It is the first planetary object to be seen transiting a white dwarf. The white dwarf star is located ~ 570 ly from Earth in the constellation Virgo.

 

[Drone]

HD 106906AB is a double star located in the constellation of Crux. This 13 million-year-old stellar duo and the disc are also accompanied by an exoplanet, visible in the upper right, named HD 106906 b, which orbits around the binary star and its disc at a distance greater than any other exoplanet discovered to date 650 AU, or ~ 97 billion km. HD 106906 b has a mammoth mass of up to 11 times that of Jupiter, and a scorching surface temperature of 1500 degrees Celsius.

 

[Drone]

Ground-based telescopes have photographed two large-scale spiral arms around two young stars, SAO 206462 and MWC 758.

Astronomers are proposing that huge spiral patterns seen around some newborn stars, merely a few million years old (~ 1% our Sun's age), may be evidence for the presence of giant unseen planets. This idea not only opens the door to a new method of planet detection, but also could offer a look into the early formative years of planet birth.

To make the grand-scale spiral arms seen in the SAO 206462 and MWC 758 systems, the unseen planet would have to be bulky, at least 10 times the mass of Jupiter, the largest planet in our solar system.

 

[Drone]

new video

This new NASA video shows behind-the-scenes footage of the heart of the James Webb Space Telescope as an engineering team lifted and lowered it into the giant thermal vacuum chamber at NASA's Goddard Space Flight Center in Greenbelt, Maryland. This final super cold test at Goddard will prepare the Integrated Science Instrument Module (ISIM), or the “heart” of the telescope, for space.

 

[Drone]

Hubble Peels Back the Layers of a Warm Neptune

About 30 ly away, a Neptune-sized planet named GJ 436b is having some of its layers peeled back.

 

[Drone]

Layers of clouds, made up of hot dust and droplets of molten iron, have been detected on a planet-like object - known as PSO J318.5-22 - which is estimated to be ~ 20 million-years-old.

PSO J318.5-22 lies 75 ly from us and it does not orbit a star. It's around the same size as Jupiter but is roughly 8 times more massive.

It's covered in multiple layers of thick and thin clouds. Temperatures inside clouds on PSO J318.5-22 exceed 800°C, researchers say.


*****

http://orig05.deviantart.net/de26/f/2015/294/d/9/exoplanetsmall_by_jaysimons-d9dv6v1.jpg


This poster shows > 500 exoplanets discovered before October 2015 arranged according to their temperature and density. Credit and copyright: Martin Vargic.


text has some errors but whatever ...

 

[CAPSLOCKSTUCK]

A rocky, oven-hot Earth-sized world that may have its own atmosphere has been spotted orbiting a small nearby star.



The planet, named GJ1132b, is around 1.2 times the size of Earth and appears to be predominantly composed of rock and iron. It is the closest Earth-sized planet to be discovered beyond our own solar system and is three times closer than those spotted previously. Astronomers have described the new world as 'arguably the most important planet ever found outside the solar system'.

GJ1132b orbits its host star – a small M-dwarf star called Gliese 1132 – at a far closer distance than the Earth is to the sun, meaning it receives about 19 times the level of radiation.

The experts said the planet is likely to have a predominantly helium and hydrogen atmosphere, but if there had been water on the surface in the planet's past, it could also have oxygen and carbon dioxide.

However, the astronomers warn that it is currently impossible to draw any firm conclusions about what the planet's atmosphere is like.

Instead, they claim the close proximity of the planet – which is around 39 light years from our own – could allow it to be directly observed using the next generation of space telescopes.

Writing in the journal Nature, Dr Zachory Berta-Thompson, an astrophysicst at the Massachusetts Institute of Technology, and his colleagues said the James Webb Space Telescope, which is due to launch in 2018, could measure the light coming from the planet to give more details about its atmosphere.

GJ1132b is around 16 per cent larger than Earth but its star, Gliese 1132 is just a fifth of the size of our sun (illustrated). However, as it orbits closer to its small star, the planet receives far more radiation


Astronomers estimate the star which the new planet is orbiting is around 21 per cent the size of our own sun. The planet was discovered using the MEarth-South telescope array, which monitors several thousand red dwarf stars located within 100 light-years of Earth. It looks for planets that pass in front of their host stars, causing the light to dim slightly. The next nearest rocky Earth-sized planets to be discovered are around 127 light years away. The astronomers behind the discovery of GJ1132b found it has a diameter of around 9,200 miles - about 16 per cent larger than the Earth – and 60 per cent more mass, suggesting it is rocky. The planet also has an Earth-like gravity and someone standing on the surface of the planet would weigh around 20 per cent more than they do on Earth. David Charbonnneau, an astronomer at the Harvard-Smithsonian Center for Astrophysics who took part in the research, said the planet was probably more like a large Venus than Earth.
He said: 'Our ultimate goal is to find a twin Earth, but along the way we've found a twin Venus. 'We suspect it will have a Venus-like atmosphere too, and if it does we can't wait to get a whiff.'

Writing in the journal Nature, Drake Deming, an astronomer at the University of Maryland who was not involved in the study, said: 'The discovery of GJ 1132b, arguably the most important planet ever found outside the Solar System. 'The significance of this new world derives from several factors. It has a radius only 16% larger than Earth’s and a matching density of 6 grams per cubic centimetre. 'Moreover, Gliese 1132, the red dwarf star around which the planet orbits, lies only 12 parsecs from the Sun — a distance that will allow astronomers to study the planet with unprecedented fidelity.'

The discovery was made using the MEarth-South telescope array (pictured), which monitors several thousand red dwarf stars located within 100 light-years of Earth. It looks for planets that pass in front of their host stars, causing the light to dim slightly
https://www.cfa.harvard.edu/MEarth/gj1132b.html

 

[Drone]

A rocky, oven-hot Earth-sized world that may have its own atmosphere has been spotted orbiting a small nearby star.



The planet, named GJ1132b, is around 1.2 times the size of Earth and appears to be predominantly composed of rock and iron. It is the closest Earth-sized planet to be discovered beyond our own solar system and is three times closer than those spotted previously. Astronomers have described the new world as 'arguably the most important planet ever found outside the solar system'.

Yeah that's right another day another exoplanet. A couple of details that article didn't cover:

GJ 1132b orbits a red dwarf star only 1/5th the size of our Sun. The star is also cooler and much fainter than the Sun, emitting just 1/200th as much light. GJ 1132b circles its star every 1.6 days at a distance of 1.4 million miles (much closer than the 36-million-mile orbit of Mercury in our solar system).

Link and diagram

https://www.cfa.harvard.edu/news/2015-24

 

[Drone]

Winds of over 2 km/s have been discovered flowing around exoplanet HD 189733b. The wind speed recorded is 20x greater than the fastest ever known on earth, where it would be seven times the speed of sound. This discovery is the first time that a weather system on an exoplanet has been directly measured and mapped.

Commenting on the discovery lead researcher Tom Louden, of the University of Warwick's Astrophysics group, said:

HD 189733b's velocity was measured using high resolution spectroscopy of the Sodium absorption featured in its atmosphere. As parts of HD 189733b's atmosphere move towards or away from the Earth the Doppler effect changes the wavelength of this feature, which allows the velocity to be measured.
The surface of the star is brighter at the center than it is at the edge, so as the planet moves in front of the star the relative amount of light blocked by different parts of the atmosphere changes. For the first time we've used this information to measure the velocities on opposite sides of the planet independently, which gives us our velocity map.

The planet is shown at three positions as it crosses its parent star. The changing background illumination allows us to separate absorption from different parts of the planetary atmosphere. By measuring the Doppler shift of the absorption we are able to measure wind velocities. The blue-shaded region of the atmosphere is moving toward the Earth at 12000 mph, while the red-shaded region is moving away from the earth at 5000 mph. After correcting for the expected spin of the planet we measure a wind velocity of 5400 mph on the blue side, indicating a strong eastward wind flow from the heated day side to the night side of the planet.



HD 189733b is one of the most studied of a class of planets known as 'Hot Jupiters'. At over 10% larger than Jupiter, but 180x closer to its star, HD 189733b has a temperature of 1800C. The day side of the planet would appear a bright shade of blue to the human eye, probably due to clouds of silicate particles high in its atmosphere.

 

[Drone]

GPI data has revealed that 51 Eri b, the recently discovered Jupiter-like exoplanet around the nearby star 51 Eridani, indeed has an atmosphere of methane and water, and likely has a mass twice that of Jupiter.

The team has also discovered and imaged disks of dusty debris around several stars. Astronomers believe that these are planetary systems that are still forming their planets. Some have complex structures because they host planets and fragments of the asteroidal and cometary materials that formed those planets. One such system is HD 131835: a massive 15 Myr-old star located 400 ly from us. Using GPI's high-contrast capability, the team imaged this disk for the first time in near-infrared light in May 2015.

“The disk shows different morphology when observed in different wavelengths. Unlike the extended disk previously imaged in thermal emission, our GPI observations show a disk that has a ring-like structure, indicating that the large grains are distributed differently from the small ones. In addition, we discovered an asymmetry in the disk along its major axis. What causes this disk to be asymmetric is the subject of ongoing investigation, “ said Li-Wei Hung, a graduate student in the UCLA Department of Physics and Astronomy and lead author of the article submitted to The Astrophysical Journal Letters. As asymmetries like the one seen in the system may be due to the gravitational influence of an unseen planet, more detailed observational study could one day confirm its existence.

 

[Drone]

CfA astronomers have announced the discovery of HAT-P-55b, a transiting hot-Jupiter around a star that is very similar to the Sun; the star's mass and radius differ from the Sun's values by only a few percent. Using additional observations to follow-up the transit discovery, the scientists determined that the exoplanet itself has a mass of 0.582 Jupiter-masses, a radius of 1.182 Jupiter-radii, and an orbital period of 3.585 days – and obtained an overall precision in its density of better than 10%. Only about 140 exoplanets have densities measured with this remarkable precision, and the new result significantly supplements the database for exoplanets, and hot-Jupiters in particular.


************


There are 450 ly between Earth and LkCa15, a young star with a transition disk around it, a cosmic whirling dervish, a birthplace for planets.

Despite the disk's considerable distance from Earth and its gaseous, dusty atmosphere, University of Arizona researchers captured the first photo of a planet in the making, a planet residing in a gap in LkCa15's disk.

Of the roughly 2000 known exoplanets only about 10 have been imaged, and that was long after they had formed, not when they were in the making.

Protoplanetary disks form around young stars using the debris left over from the star's formation. It is suspected that planets then form inside the disk, sweeping up dust and debris as the material falls onto the planets instead of staying in the disk or falling onto the star. A gap is then cleared in which planets can reside.

 

[Drone]

Astronomers studying a lonely planet drifting through space have found its mum; a star a trillion kilometers away.

The planet 2MASS J2126-8140 has an orbit around its host red dwarf star called TYC 9486-927-1 that takes nearly a million Earth years and is > 140 times wider than Pluto's. This makes it easily the largest solar system ever found.

Only a handful of extremely wide pairs of this kind have been found in recent years. The distance between the new pair is 6900 AU - 10^12 km or 0.1 ly - nearly three times the previous widest pair, which is 2500AU (370,000,000,000 km). 2MASS J2126-8140 is a gas giant planet ~ 12-15 times the mass of Jupiter.

This gas giant and its host star are ~ 100 ly away. They formed 10-45 million years ago from a filament of gas. They must not have lived their lives in a very dense environment. They are so tenuously bound together that any nearby star would have disrupted their orbit completely.

Arrows show motion over next 1000 years.

 

[Drone]

Gemini Confirms a Free-Floating Planet PSO J318.5-22

An extremely red planetary-mass object is confirmed, based on Gemini observations, to be a free-floating member of the Beta Pictoris moving group.

​

Estimates of the mass of such objects are extremely sensitive to age, so confirmation of the group membership yields a more reliable mass: 8.3 ± 0.5 times the mass of Jupiter, with an effective temperature of 1127 K. The Gemini spectra reveal that the body rotates at between 5-10.2 hours and its radial velocity (- 6.4 ± 1.7 km/s) is within the envelope expected for members of the group. PSO J318.5-22 is 23±3 Myr old.

 

[Drone]

Exoplanets keep spamming the cosmos lol. Two new interesting images from ALMA:

The dust ring possibly sculpted by planets around the star Sz 91, at a distance ~ 650 ly from Earth. Sz 91 has only half of the mass of our Sun. The dust ring is surprisingly large, > 3 times the size of Neptune's orbit (a radius of ~ 110 AU).
Planets are born in dust and gas disks that surround young stars and feed them with matter. The giant planets carve the protoplanetary disk, creating a “hole” in the innermost part of the disk, and preventing mm-sized dust particles (like grains of sand on a beach) from continuing their journey towards the central star. At the same time, dust particles in the outermost parts of the disk are moving inward by the combined action of gravity and aerodynamic forces (gas-drag).

Astronomers took a new, detailed look at the planet-forming disk around HD 142527, a binary star ~ 450 ly from Earth.
HD 142527 consists of a main star a little more than twice the mass of our Sun and a smaller companion star only ~ 1/3 the mass of our Sun. They are separated by a little more than the distance from the Sun to Saturn.

ALMA's new, high-resolution images show a broad elliptical ring around HD 142527. The disk begins incredibly far from the central star ~ 50 AU. Most of it consists of gases, including two forms of carbon monoxide (13CO and C18O) [blue and green], but there is a noticeable dearth of gases within a huge arc of dust (red) that extends nearly a third of the way around the star system. The temperature is so low that the gas turns into ice and sticks to the grains. This process is thought to increase the capacity for dust grains to stick together, making it a strong catalyst for the formation of planets.

 

[Drone]

Maaaan, I remember when 6 years ago Kepler detected 5 hot Jupiters in 6 weeks! Now WASP [Wide Angle Search for Planets] does the same!

​

5 transiting hot Jupiters discovered using WASP-South, Euler and TRAPPIST: WASP-119 b, WASP-124 b, WASP-126 b, WASP-129 b and WASP-133 b

The planets discovered are hot Jupiter systems with orbital periods in the range 2.17-5.75 days, masses from 0.3MJup-1.2MJup and with radii from 1RJup-1.5RJup. These planets orbit bright stars (V = 11-13) with spectral types in the range F9-G4.

1) With a mass of 1.2 of the mass of Jupiter, and an orbital period of 2.5 days, WASP-119 b is a typical hot Jupiter. Its host star has a similar mass to the sun's but appears to be much older based on its effective temperature and density.

2) WASP-124 b is less massive than Jupiter (0.6MJup), has orbital period of 3.4 days and a much younger parent star.

3) WASP-126 b orbits the brightest star in this sample. It's a low-mass planet with a large radius (0.3MJup, 0.95RJup), making it a good target for transmission spectroscopy.

4) Similar in size to Jupiter, WASP-129 b has the longest orbital period. Its surface gravity is also high compared to other known 'hot Jupiters'. The high density of its host star WASP-129 A suggests that it's a helium-rich star similar to HAT-P-11 A.

5) WASP-133 b has the shortest orbital period of the exoplanets presented in the study. It's slightly bigger than Jupiter (1.2MJup, 1.2RJup). Its host star WASP-133 has an enhanced surface lithium abundance compared to other old G-type stars, particularly other planet host stars.

​

Don't take the images seriously