Exoplanets

Drone · May 10, 2016

Kepler Mission Has Identified 1284 New Exoplanets

An additional 1327 candidates are more likely than not to be actual planets, but they do not meet the 99% threshold and will require additional study. The remaining 707 are more likely to be some other astrophysical phenomena. This analysis also validated 984 candidates previously verified by other techniques.

In the newly-validated batch of planets, nearly 550 could be rocky planets like Earth, based on their size. 9 of these orbit in their sun's habitable zone. 21 exoplanets now are known to be members of this exclusive group.

Drone · May 11, 2016

Duh, back in 2015 KIC 8462852 got so much attention, alien megastructure and blablabla

New Study Supports Natural Causes to Explain Behavior of KIC 8462852

KIC 8462852 (aka TYC 3162-665-1) is a main-sequence F-type star located in the constellation Cygnus, ~ 1480 ly away.

NASA's Kepler Space Telescope had monitored this star for several years, observing unusual incidents in 2011 and 2013, when the star's light dimmed in never-before-seen ways.

The star had deep dips in brightness – up to 22%, indicating that a large number of objects had passed across the star’s disk and temporarily blocked some of the light coming from it.

In October 2015, a team of astronomers at Pennsylvania State University released a preprint paper that cited KIC 8462852's light curve as 'consistent with' a swarm of alien megastructures.

The attention caused astronomers at the SETI Institute to train their Alien Telescope Array on KIC 8462852 to see if they could detect any radio signals indicating the presence of an alien civilization. In November 2015 the team reported finding 'no evidence' of signals with an artificial origin.

Then a study released in January 2016 by Dr. Bradley Schaefer from Louisiana State University threw even more fuel on the fire of alien speculation by announcing that the brightness of KIC 8462852 had dimmed by 20% over the last century.

However, the new study, led by German astronomer Michael Hippke, has taken a detailed look at the observations on which the study by Dr. Schaefer was based and concluded there is no credible evidence that the brightness of the star been steadily changing over this period.

“We looked at variations in the brightness of a number of comparable stars in the Digital Access to a Sky Century at Harvard (DASCH) database and found that many of them experienced a similar drop in intensity in the 1960’s,” said co-author Prof. Keivan Stassun of Vanderbilt University.

“That indicates the drops were caused by changes in the instrumentation not by changes in the stars' brightness.”

“Even if aliens are not involved, KIC 8462852 remains the most mysterious star in the Universe,” said Dr. Tabetha Boyajian of Yale University, who was not involved in the current study.

“It would take an object 1000 times the area of the Earth transiting the distant star to produce such a dramatic effect.”

The team considered a number of possible explanations, including variations in the KIC 8462852's output, the aftermath of an Earth/Moon type planetary collision, interstellar clumps of dust passing between the star and Earth, and some kind of disruption by the star's apparent dwarf companion. However, none of their scenarios could explain all of the observations.

Their best explanation was a giant comet that fragmented into a cascade of thousands of smaller comets.

“What does this mean for the mystery? Are there no aliens after all? Probably not! Still, the dips found by Kepler are real. Something seems to be transiting in front of this star and we still have no idea what it is,” Hippke said.

Drone · May 11, 2016

Kepler-223: Astronomers Find System with 4 Giant Planets Trapped in Resonance

Kepler-223 is a star very similar in size and mass to the Sun but much older (> 6 billion years old).

The planets of Kepler-223 system - Kepler-223 b, c, d, e - are so-called sub-Neptunes – they are much larger than Earth, likely consisting of a solid core and an envelope of gas, and they orbit their star in periods ranging from only 7 to 19 days.

Kepler-223 b and c – the system's two innermost planets – are in a 4:3 resonance. Kepler-223 c and d are in a 3:2 resonance. And Kepler-223 d and e are in a 4:3 resonance.

Astronomers think that two planets migrate through the gaseous disk, get stuck and then keep migrating together; find a third planet, get stuck, migrate together; find a fourth planet and get stuck.

That process differs completely from the one that astronomers believe led to the formation of Earth, Mercury, Venus, and Mars, which likely formed in their current orbital locations.

Earth formed from Mars- or Moon-sized bodies smacking together, a violent and chaotic process. When planets form this way their final orbital periods are not near a resonance.

But scientists suspect that Jupiter, Saturn, Uranus, and Neptune moved around substantially during their formation. They may have been knocked out of resonances that once resembled those of Kepler-223, possibly after interacting with numerous asteroids and small planets.

Planets are in resonance when, for example, every time one of them orbits its sun once, the next one goes around twice. Jupiter's moons, where the phenomenon was discovered, display resonance.

Drone · May 13, 2016

5 Planets Where The Weather Will Straight-Up Kill You

Drone · May 18, 2016

Astronomers using ALMA have made the first high-resolution image of the cometary belt around HR 8799, the only star where multiple planets have been imaged directly. The shape of this dusty disk, particularly its inner edge, is surprisingly inconsistent with the orbits of the planets, suggesting that either they changed position over time or there is at least one more planet in the system yet to be discovered.

The disk, which fills a region 150-420 AU, is produced by the ongoing collisions of cometary bodies in the outer reaches of this star system. ALMA was able to image the emission from mm-size debris in the disk; according to the researchers, the small size of these dust grains suggests that the planets in the system are larger than Jupiter.

HR 8799 is a young star ~ 1.5 times the mass of the Sun located 129 ly from Earth in the direction of the constellation Pegasus.

Drone · May 27, 2016

A robotic survey of the southern sky has discovered its first exoplanet: KELT-10b, a highly inflated giant planet. Although it's only 2/3 the mass of Jupiter, KELT-10b is 40% larger than Jupiter in radius. Because of its large size, when the planet passes in front of its star, it blocks out a whopping 1.4% of the star's light, generating a transit signal that is relatively easy to detect.

Lightcurve of exoplanet KELT-10b is overlaid on an image of the KELT-S Telescope in South Africa.

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U.S. astronomers announced the discovery of a giant planet in close orbit around a star so young that it still retains a disk of circumstellar gas and dust.

CI Tau b is at least 8 times larger than Jupiter and orbits a 2 million-year-old star about 450 ly from Earth in the constellation Taurus.
CI Tau b orbits the star CI Tau once every 9 days.

This result is unique because it demonstrates that a giant planet can form so rapidly that the remnant gas and dust from which the young star formed, surrounding the system in a Frisbee-like disk, is still present. Giant planet formation in the inner part of this disk, where CI Tau b is located, will have a profound impact on the region where smaller terrestrial planets are also potentially forming.

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Using the Gemini Planet Imager astronomers have successfully monitored the motion of a planet around the forming exoplanet system orbiting the star HD 95086 and suggest that more unseen planets are present.

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Drone · Jun 8, 2016

10 Most Intriguing Exoplanets

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10 Exoplanets That Could Host Alien Life

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Drone · Jun 9, 2016

Scientists working at the Stellar Astrophysics Centre have discovered a new giant exoplanet K2-39b

K2-39b orbits extremely close to its host star [at a distance of only 1.7 times the diameter of the star]. By comparison, Earth is > 100 solar diameters away from the Sun. On the other hand, the subgiant star hosting the planet is ~ 4 times larger than the Sun.

Vincent Van Eylen, who led the study says:

"Previously, we thought perhaps such planets would quickly be destroyed due to tidal interactions once the host star evolves.
K2-39b hasn't been destroyed, or at least not yet, so either the tidal destruction is not as efficient as we may have thought or feared, or the planet may be destroyed in the next few thousand years. But if that's the case, it would be an extreme coincidence that we found it in the first place, and the effects of tidal decay should become visible within the next few years."

Further studies of planets orbiting evolved stars will help understand the fate of planets as their host stars grow older. The same will happen to the solar system in a few billion years, when Sun will evolve into a giant star.

Drone · Jun 10, 2016

Likely new giant planet PTFO8-8695 b is believed to orbit a star in the constellation Orion every 11 hours. Gravity from the newborn star appears to be pulling away the outer layers of the Jupiter-like planet.

Drone · Jun 11, 2016

Was surfing through youtube and found pretty interesting videos:

Drone · Jun 13, 2016

Another day another exoplanet!

New exoplanet named CVSO 30c [the small dot to the upper left of the frame, the large blob is the star itself]. While the previously-detected planet, CVSO 30b, orbits very close to the star, whirling around CVSO 30 in just under 11 hours at an orbital distance of 0.008 AU, CVSO 30c orbits significantly further out, at a distance of 660 AU, taking a staggering 27 000 years to complete a single orbit. (For reference, the planet Mercury orbits the Sun at an average distance of 0.39 AU, while Neptune sits at just over 30 AU.)

If it is confirmed that CVSO 30c orbits CVSO 30, this would be the first star system to host both a close-in exoplanet detected by the transit method and a far-out exoplanet detected by direct imaging. Astronomers are still exploring how such an exotic system came to form in such a short timeframe, as the star is only 2.5 million years old; it is possible that the two planets interacted at some point in the past, scattering off one another and settling in their current extreme orbits.

Drone · Jun 20, 2016

Newborn Exoplanet Discovered Around Young Star

The planet, K2-33b, at 5-10 million years old, is still in its infancy. It is ~ 6 times the size of Earth (~50% than Neptune) and makes a complete orbit around its host star in ~ 5 days. This implies that it is 20 times closer to its star than Earth is to the Sun.

Pretty informative video by Glyn Collinson from NASA's Goddard spaceflight center. He explains how "electric wind" can strip Earth-like planets of oceans and atmospheres.

Drone · Jul 4, 2016

Qatari astronomers discover 3 'hot Jupiters'

Qatar-3b, Qatar-5b are of a similar size, at 4.31 and 4.32 Jupiter masses, while Qatar-4b ~ 5.85 times the mass of Jupiter.

They are all bigger than Jupiter (12-17 times larger than Earth). Qatar-4b is the largest, at 1.55 times Jupiter's radius.

They also have temperatures between 1400-1700°C and the distances to the new planets are 1400-1800 ly away.

Drone · Jul 5, 2016

Exoplanet Kepler-10b is believed to experience up to a trillion lightning strikes per hour.

Exoplanet HD131399Ab has three suns

Drone · Jul 31, 2016

There is an 85% probability that there is an Earth-like planet around Alpha Centauri A or B.

Learn more about Mission Centaur

Earth Proxima

Drone · Aug 9, 2016

Lisa Kaltenegger, professor of astronomy and director of the Carl Sagan Institute, shares what inspires her scientific curiosity. Kaltenegger's research focuses on the characterization of habitable worlds.

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We've been paying attention to the star that scientists think could have the capability of supporting advanced life for a while, and things are getting even more interesting now.

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Really awesome and informative top 5. I wonder how I missed that video.

Drone · Aug 22, 2016

Not exactly new but really interesting videos where scientists Sara Seager & Lisa Kaltenegger explain how they search for exoplanets and their atmospheres.

This is just for fun:

Fun Facts About Photosynthesis

And this one is unrelated but really interesting nonetheless

The Loneliest Place in the Universe

Drone · Aug 24, 2016

Earth-like planet found orbiting habitable zone of nearest star :eek:

Drone · Aug 29, 2016

Ok, I was complaining that there are no discoveries. Here comes trouble. Aliens On-line! Kinda ... or maybe it's just a microlensing.

Is Earth being contacted by ALIENS? Mystery radio signals coming from a sun-like star baffle scientists

What we know of HD 164595 is that it's a star of 0.99 solar masses at a distance of roughly 95 ly in the constellation Hercules, and an estimated age of 6.3 billion years. Its metallicity is almost identical to that of the Sun. A known planet in this system, HD 164595 b, is 0.05 Jupiter mass with a period of 40 days, considered to be a warm Neptune on a circular orbit. There could, of course, be other planets still undetected in this system.

http://www.seti.org/seti-institute/a-seti-signal

Drone · Sep 1, 2016

A team of Carnegie scientists has discovered a highly unusual system.

Star HD 133131A hosts 2 moderately eccentric planets, one of which is, at a minimum, ~ 1.5 times Jupiter's mass and the other of which is, at a minimum, just >0.5 Jupiter's mass. Star HD 133131B hosts one moderately eccentric planet with a mass at least 2.5 times Jupiter's.

The two stars themselves are separated by only 360 AU. The system represents the smallest-separation binary in which both stars host planets that has ever been observed.

The system is even more unusual because both stars are 'metal poor'.

Adding to the intrigue, scientists used very precise analysis to reveal that the stars are not actually identical 'twins' as previously thought, but have slightly different chemical compositions, making them more like the stellar equivalent of fraternal twins.

This could indicate that one star swallowed some baby planets early in its life, changing its composition slightly. Alternatively, the gravitational forces of the detected giant planets that remained may have had a strong effect on fully-formed small planets, flinging them in towards the star or out into space.

Drone · Sep 13, 2016

In 2015, astronomers reported unusual behavior in the star KIC 8462852 that they could not explain. Now, another team has discovered a second star that behaves similarly to KIC 8462852. It's called EPIC 204278916 and it's even stranger than the first one.

This young, dusty, disk-bearing star reminds us 'Alien Megastructures' aren't the only answer.

Authors offer two potential explanations for the big flux dips that they see that's also consistent with everything else observed:

a warped inner disk transiting circumstellar clumps in circular orbits
cometary-like debris in an eccentric orbit