Tag: exoplanet

Astronomers snap picture of a baby exoplanet

10:08 am

Baby planet
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken using Magellan Telescope in Chile and the Large Binocular Telescope in Arizona. The exoplanet is the small purple dot to the right of the star and the accretion ring that surrounds it.

This exoplanet is very young, only about five million years old, and is thus still accumulating material. Even so, its mass is presently estimated to be five times that of Jupiter.

Following [the first] observations of the system, researchers looked at WISPIT 2, and spotted the planet WISPIT 2b for the first time, using the University of Arizona’s MagAO-X extreme adaptive optics system, a high-contrast exoplanet imager at the Magellan 2 (Clay) Telescope at Las Campanas Observatory in Chile. This technology adds another unique layer to this discovery. The MagAO-X instrument captures direct images, so it didn’t just detect WISPIT 2b, it essentially captured a photograph of the protoplanet.

…In addition to discovering WISPIT 2b, this team spotted a second dot in one of the other dark ring gaps even closer to the star WISPIT 2. This second dot has been identified as another candidate planet that will likely be investigated in future studies of the system.

You can read the paper here [pdf]. The other candidate exoplanet is the bright spot below the star, inside the ring.

The technology of astronomy continues to advance.

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Exoplanet detected inside gap in accretion disk surrounding a Sunlike star

9:30 am

Exoplanet in gap of disk

For the first time since 2018, scientists have obtained a clear detection of an exoplanet inside the accretion disk surrounding a Sunlike star. Furthermore, the planet sits inside a gap in that accretion disk, the first time such an exoplanet has been found.

The image to the right, taken from figure one of the research paper [pdf], shows the exoplanet, dubbed WISPIT 2b. The star, located about 435 light years away, has a mass only slightly larger than our Sun, and is considered a close match. The planet itself is estimated to be about the mass of Jupiter, though its orbit within that gap is much farther away, 57 astronomical units versus 5.2. It is these details that make the discovery significant. From the paper’s conclusion:

As the planet resides in the cleared gap and its mass is consistent with the modeled planet mass required to open such a gap, we argue that it likely formed in situ through core accretion and that there is no rapid migration on dynamical timescales. Future follow-up observations of WISPIT 2b with ALMA and [Webb] will enable studies of its atmosphere and the impact of the embedded planet on the disk’s gas kinematics and surface density structure. This will allow us to calibrate ALMA observations of other embedded planet candidates, to unlock the full potential of this complementary technique.

…The discovery of WISPIT 2b embedded in the gap of a seemingly unperturbed disk demonstrates, for the first time, that wide-separation gas giants, discovered by direct imaging around older systems, can indeed form in situ. Thus, WISPIT 2b marks a promising starting point to study wide separation planets in time.

It has long been theorized that gas giants can form much farther from their star, and then migrate inward as the system evolves. This discovery counters that supposition, or least demonstrates that it does not have to occur in every new solar system.

The image also shows that the accretion disk has a second gap farther out, as well as a cleared area close to the star, comparable in size to our solar system. Though other exoplanets have not been detected yet, these gaps suggest they exist, thus indicating that a solar system comparable to our own is now forming.

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New data raises doubts about exoplanet having chemicals that on Earth come from life

1:02 pm

The uncertainty of science: Using new data from the Webb Space Telescope, scientists now conclude that the identification on an exoplanet in April 2025 of the molecules dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS) — both of which on Earth are only associated with the presence of life — is now uncertain and that these molecules likely aren’t there.

The new work uses [Webb] data to better qualify what is going on. The work confirms the presence of an ocean on this peculiar exoplanet, although it can’t confirm if there is a thick or thin atmosphere. They couldn’t find water vapor in the atmosphere, suggesting that there is an efficient cold trap, keeping evaporation to a minimum on this temperate sub-Neptune world.

Those potential biosignatures were all below the threshold for an undeniable detection, and their model suggests that a possible presence of DMS could be explained by sources unrelated to life. They advise considering more and different molecules to use as biosignatures. Astronomers are studying worlds that are very different from our own, and the chemical signatures that seem obvious here on Earth might not fit well with those exoplanets.

In other words, they simply don’t have enough data to know, one way or the other. No surprise, The science of studying exoplanets is in its infancy, and right now can only tease out the smallest of details based on our limited technology and the distances involved.

You can read the new paper here [pdf]. It notes further that using these molecules as a sign of life is also a mistake, as they can be created in other ways having nothing to do with biology.

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Astronomers detect exoplanet shaping the protoplanetary disk surrounding a baby star

9:41 am

Star with disk
Click for original image.

Astronomers using two different instruments on the Very Large Telescope (VLT) in Chile have now directly detected what they think is an exoplanet as it shapes the spiral arms of a baby star’s protoplanetary disk.

In the case of HD 135344B’s disc, swirling spiral arms had previously been detected by another team of astronomers using SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch), an instrument on ESO’s VLT. However, none of the previous observations of this system found proof of a planet forming within the disc.

Now, with observations from the new VLT’s Enhanced Resolution Imager and Spectrograph (ERIS) instrument, the researchers say they may have found their prime suspect. The team spotted the planet candidate right at the base of one of the disc’s spiral arms, exactly where theory had predicted they might find the planet responsible for carving such a pattern.

The newly detected object however might be a brown dwarf and not an exoplanet. More observations are required to reduce the uncertainty.

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Webb takes infrared image of exoplanet

9:32 am

Webb's image of exoplanet

Using the Webb Space Telescope astronomers have now successfully taken an infrared false-color image of Saturn-sized exoplanet orbiting a young star about half the mass of the Sun and about 111 light years away.

The image is to the right, cropped and reduced to post here. The star, its light blocked out, is indicated by the circle with the star in the middle. The exoplanet is the orange blob to the upper right, sitting inside the blue accretion disk that surrounds the star, photographed in optical light by the Very Large Telescope in Chile.

You can read the paper here. The scientists rejected the possibility that this was a background galaxy after doing computer modeling, based on the data available. From their paper:

Dedicated N-body simulations were conducted for a planet with a mass of 0.34 [mass of Jupiter], located at 52 au [astronomical units] around the 0.46 [solar mass] central star. This value is consistent with the measured projected separation, assuming that the planet and the ≈13°-inclined disk are coplanar. The simulation also included a disk of 200,000 planetesimals, distributed between 20 and 130 au. These parameters were selected to roughly match the boundaries of the observed disk.

Note too that the picture to the right has been significantly enhanced by the press department at JPL, based on the actual data shown in the paper itself. These fact underline the uncertainties involved in this discovery.

Nonetheless, it is a good result, and suggests we are looking at the formation process of a new solar system surrounding a very young baby star.

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Astronomers detect evidence of exoplanet in weird orbit

9:13 am

Perpendicular planet
Click for original image.

Though there is much uncertainty in their data, astronomers now believe they have discovered an exoplanet orbiting a binary system of two brown dwarfs, but doing so tilted 90 degrees to the ecliptic of the orbits of those brown dwarfs.

The graphic to the right illustrates the theorized system, with the orbits of the brown dwarfs indicated in blue and the exoplanet’s orbit in orange. While sixteen exoplanets have been found orbiting outside a binary pair of stars, this is the first doing so at such an inclination.

The detection has great uncertainty however.

The candidate planet cannot be detected the way most exoplanets – planets around other stars – are found today: the “transit” method, a kind of mini-eclipse, a tiny dip in starlight when the planet crosses the face of its star.

Instead they used the next most prolific method, “radial velocity” measurements. Orbiting planets cause their stars to rock back and forth ever so slightly, as the planets’ gravity pulls the stars one way and another; that pull causes subtle, but measurable, shifts in the star’s light spectrum. Add one more twist to the detection in this case: the push-me-pull-you effect of the planet on the two brown dwarfs’ orbit around each other. The path of the brown dwarf pair’s 21-day mutual orbit is being subtly altered in a way that can only be explained, the study’s authors conclude, by a polar-orbiting planet.

The radial velocity method however requires the scientists to make a number of assumptions, and provides limited information that can result in a misinterpretation of the data. It is for this reason this exoplanet is described as a “candidate planet.” Its theorized existence must be confirmed by other measurements before it is considered real.

I think this was posted as a quick link back in early May, when the scientists first announced their work, but can’t find it now.

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Astronomers discover nearby Earth-sized exoplanet only slightly hotter than Earth

10:49 am

Using the TESS space telescope as well as a number of ground-based telescopes astronomers have discovered an Earth-sized exoplanet only 40 light years away that has a surface temperature estimated to be about 107 degrees Fahrenheit, assuming it has no atmosphere.

The host star, called Gliese 12, is a cool red dwarf located almost 40 light-years away in the constellation Pisces. The star is only about 27% of the Sun’s size, with about 60% of the Sun’s surface temperature. The newly discovered world, named Gliese 12 b, orbits every 12.8 days and is Earth’s size or slightly smaller — comparable to Venus. Assuming it has no atmosphere, the planet has a surface temperature estimated at around 107 degrees Fahrenheit (42 degrees Celsius).

At the moment however scientists do not yet know if the exoplanet has an atmosphere or not. Follow-up observations using the Webb Space Telescope are planned to find this out. Based on the data presently available, the exoplanet could either be like Venus, too hot to sustain life, or like Earth, cooler with water and an atmosphere and thus very habitable.

Gliese 12 b could therefore become one of the primary targets for the first interstellar missions once humanity begins such exploration.

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Earth-sized exoplanet discovered orbiting dwarf star 55 light years away

10:49 am

Using a number of ground-based telescopes worldwide, astronomers have discovered an Earth-sized exoplanet orbiting what the scientists label an “ultra-cool” dwarf star only about 55 light years away.

You can read the paper here.

Though Earth-sized, this exoplanet is not habitable. It orbits the star every 17 hours and is believed to be tidally locked, with one side always facing the star. More important, though this red dwarf star has likely existed for many tens of billions of years and will continue for many tens of billions of years into the future, the star is too dim and lacking in the kind of resources needed for life. It also drenches the planet with bursts of radiation, which is also believed to have stripped the planet of an atmosphere.

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Webb data suggests a super-Earth might have an atmosphere

10:20 am

Using infrared data from the Webb Space Telescope, scientists now think the hot super-Earth exoplanet dubbed 55 Cancri e and 41 light years away might have an atmosphere made up not only of vaporized molten rock but other gases as well, such as carbon dioxide or carbon monoxide.

The exoplanet orbits much too close to its star, only 1.4 million miles away, for any life as we know it to exist. Its surface is thought to be molten, heated by that star.

The team thinks that the gases blanketing 55 Cancri e would be bubbling out from the interior, rather than being present ever since the planet formed. “The primary atmosphere would be long gone because of the high temperature and intense radiation from the star,” said Bello-Arufe. “This would be a secondary atmosphere that is continuously replenished by the magma ocean. Magma is not just crystals and liquid rock; there’s a lot of dissolved gas in it, too.”

As always, these results remain unconfirmed and are very uncertain.

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Webb maps the global temperature and water vapor of a hot exoplanet

10:37 am

The uncertainty of science: Using detailed infrared data from the Webb Space Telescope, scientists have mapped the temperature swings and atmospheric water vapor across the entire global of a tidally locked “hot Jupiter” exoplanet about 284 light years away that orbits its star every 19.5 hours.

The team used Webb’s MIRI (Mid-Infrared Instrument) to measure light from the WASP-43 system every 10 seconds for more than 24 hours. “By observing over an entire orbit, we were able to calculate the temperature of different sides of the planet as they rotate into view,” explained Bell. “From that, we could construct a rough map of temperature across the planet.”

The measurements show that the dayside has an average temperature of nearly 2,300 degrees Fahrenheit (1,250 degrees Celsius) – hot enough to forge iron. Meanwhile, the nightside is significantly cooler at 1,100 degrees Fahrenheit (600 degrees Celsius). The data also helps locate the hottest spot on the planet (the “hotspot”), which is shifted slightly eastward from the point that receives the most stellar radiation, where the star is highest in the planet’s sky. This shift occurs because of supersonic winds, which move heated air eastward.

…To interpret the map, the team used complex 3D atmospheric models like those used to understand weather and climate on Earth. The analysis shows that the nightside is probably covered in a thick, high layer of clouds that prevent some of the infrared light from escaping to space. As a result, the nightside – while very hot – looks dimmer and cooler than it would if there were no clouds.

The data also found water vapor on both the day and night sides of the exoplanet, but surprisingly no evidence of methane, suggesting that atmosphere has high winds exceeding 5,000 miles per hour that mixes that atmosphere globally. Any methane that was expected to exist on the night side gets blown to the day side where the heat destroys it.

This data, while excellent, is also very coase and even more uncertain. While Webb can get good infrared spectroscopy from almost 300 light years away, we must take the interpretations of that data with great skepticism.

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Hubble detects changes in atmosphere of exoplanet

10:16 am

Using data from collected in 2016, 2018, and 2019 combined with computer simulations, scientists now believe they have detected changes in the atmosphere of the exoplanet WASP-121b, also nicknamed Tylos.

The Jupiter-sized planet orbits a star about 880 light years away.

WASP-121 b is so close to its parent star that the orbital period is only 1.27 days. This close proximity means that the planet is tidally locked so that the same hemisphere always faces the star, in the same way that our Moon always has the same side pointed at Earth. Daytime temperatures approach 3,450 degrees Fahrenheit (2,150 degrees Kelvin) on the star-facing side of the planet.

The team used four sets of Hubble archival observations of WASP-121 b. The complete data-set included observations of WASP-121 b transiting in front of its star (taken in June 2016); WASP-121 b passing behind its star, also known as a secondary eclipse (taken in November 2016); and the brightness of WASP-121 b as a function of its phase angle to the star (the varying amount of light received at Earth from an exoplanet as it orbits its parent star, similar to our Moon’s phase-cycle). These data were taken in March 2018 and February 2019, respectively.

A computer model was then used to fill in the gaps and provide a simulation of the hot temperatures of that exoplanet’s atmosphere over time. Two videos of that simulation are available at the link.

There of course is a lot of uncertainty in this result, though the fundamental discovery of changes is important. This data proves there is weather on such alien planets, even if that weather is so alien we really don’t understand it in the slightest based on the available data on hand.

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Scientist creates longest time-lapse movie of exoplanet circling its star

9:37 am

A scientist at Northwestern University has used seventeen years of data to create the longest time-lapse movie yet of an exoplanet circling its star, Beta Pictoris, which is located 63 light years away.

Constructed from real data, the footage shows Beta Pictoris b — a planet 12 times the mass of Jupiter — sailing around its star in a tilted orbit. The time-lapse video condenses 17 years of footage (collected between 2003 and 2020) into 10 seconds. Within those seconds, viewers can watch the planet make about 75% of one full orbit.

“We need another six years of data before we can see one whole orbit,” said Northwestern astrophysicist Jason Wang, who led the work. “We’re almost there. Patience is key.”

I have embedded the video below. Because the star in the center is so bright, its light is blocked out, so that this part of the planet’s orbit is represented by the “X” in the video.
» Read more

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More direct images released of exoplanet 87.5 light years away

9:56 am

Keck images of exoplanet over time

The Keck Observatory in Hawaii has now released its own image of the exoplanet AF Leporis b, following up the images produced by the Very Large Telescope (VLT) released in February.

The direct images Franson’s team captured revealed that AF Lep b is about three times the mass of Jupiter and orbits AF Leporis, a young Sun-like star about 87.5 light-years away. They took a series of deep images of the planet starting in December 2021; two other teams also captured images of the same planet since then.

What make the Keck observations most interesting is that they captured over time the motion of the exoplanet as it orbited its star. The two images to the right show this motion.

The paper, available here, was published today in Astrophysical Journal Letters. This particular star also has a debris disk surrounding it, suggesting it is a young solar system still in the process of forming. From the paper’s conclusion:

AF Lep joins other young planet hosts with debris disks such as β Pic, HR 8799, HD 206893, and HD 95086, reinforcing indications of a higher frequency of long-period planets orbiting stars hosting debris disks.

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Astronomers discover Earth-sized planet 90 light years away

9:40 am

Using data from a variety of space- and ground-based telescopes astronomers have discovered Earth-sized exoplanet orbiting a red dwarf star 90 light years away.

The exoplanet is dubbed LP 791-18 d, and is thought to be slightly bigger than the Earth. Its orbit, close to the star, causes it to be tidally-locked, with one hemisphere always facing the star. In addition, the presence of another much larger exoplanet in the system causes other tidal effects.

Astronomers already knew about two other worlds in the system before this discovery, called LP 791-18 b and c. The inner planet b is about 20% bigger than Earth. The outer planet c is about 2.5 times Earth’s size and more than seven times its mass.

During each orbit, planets d and c pass very close to each other. Each close pass by the more massive planet c produces a gravitational tug on planet d, making its orbit somewhat elliptical. On this elliptical path, planet d is slightly deformed every time it goes around the star. These deformations can create enough internal friction to substantially heat the planet’s interior and produce volcanic activity at its surface. Jupiter and some of its moons affect Io in a similar way.

The press release makes a big deal about the volcanism, even suggesting it could produce an atmosphere that, because the exoplanet sits on the inner edge of the habitable zone, could make the exoplanet habitable. These speculations are silly, considering the uncertainties, the exoplanet’s evolving orbit, and the star it orbits, and are being pushed mostly because the press office thinks this will be the only way the public will have any interest in the discovery.

While there is an infinitesimal chance there could be life here, a more likely scenario is that it is a lifeless volcano world like Jupiter’s moon Io. Even more probably however is that it is completely different than anything we have yet observed, in ways we can’t yet predict. To find out however we would need close-up observations that will likely not be possible without an interstellar mission.

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First exoplanet confirmed by Webb

10:23 am

Astronomers have used for the first time the Webb Space Telescope to confirm the existence of an exoplanet, previous noted in data from the orbiting TESS telescope.

Formally classified as LHS 475 b, the planet is almost exactly the same size as our own, clocking in at 99% of Earth’s diameter. The research team is led by Kevin Stevenson and Jacob Lustig-Yaeger, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The team chose to observe this target with Webb after carefully reviewing targets of interest from NASA’s Transiting Exoplanet Survey Satellite (TESS), which hinted at the planet’s existence. Webb’s Near-Infrared Spectrograph (NIRSpec) captured the planet easily and clearly with only two transit observations.

The data is still preliminary, so more analysis is necessary to provide some information about the planet’s atmosphere.

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Kepler’s first discovered exoplanet is spiraling into its aging star

9:33 am

Measurements of the orbit of first exoplanet discovered by the Kepler space telescope have determined that its orbit is very slowly shrinking, and that it will eventually spiral into its aging sun.

In the case of Kepler-1658b, according to the new study, its orbital period is decreasing at the miniscule rate of about 131 milliseconds (thousandths of a second) per year, with a shorter orbit indicating the planet has moved closer to its star.

Detecting this decline required multiple years of careful observation. The watch started with Kepler and then was picked up by the Palomar Observatory’s Hale Telescope in Southern California and finally the Transiting Exoplanet Survey Telescope, or TESS, which launched in 2018. All three instruments captured transits, the term for when an exoplanet crosses the face of its star and causes a very slight dimming of the star’s brightness. Over the past 13 years, the interval between Kepler-1658b’s transits has slightly but steadily decreased.

The scientists think tidal forces are causing the orbit to shrink. The star itself is old and beginning to expand as it evolves towards its own stellar death.

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Earthlike exoplanet in habitable zone detected orbiting nearest star

9:21 am

The uncertainty of science: Astronomers think they have detected an Earthlike exoplanet, in habitable zone, orbiting Proxima Centauri, the nearest star to our solar system.

Astronomer João Faria and his collaborators detected Proxima Centauri d by measuring tiny shifts in the spectrum of the star’s light as the planet’s gravity pulled it during orbit. The team used a state-of-the art spectrograph called ESPRESSO at the Very Large Telescope, a system of four 8.2-metre telescopes at the European Southern Observatory in Cerro Paranal, Chile. The results were published on 10 February in Astronomy & Astrophysics.

This ‘wobble’ technique looks for changes in the star’s motion along the line of sight from Earth, and ESPRESSO can detect variations of just 10 centimeters per second. The total effect of the planet’s orbit, which lasts only five days, is about 40 cm/s, says Faria. “I knew that ESPRESSO could do this, but it was still surprised to see it showing up,” says Faria, who is at the Institute of Astrophysics and Space Sciences in Porto, Portugal.

Though the scientists are very confident about their results, the detection is at present only a candidate planet, as its existence has not been confirmed by an second independent method. Also, the method of detection cannot pin down the exoplanet’s mass very precisely, though it suggests the exoplanet has rocky planet mass, not too different than Earth’s.

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Calling this exoplanet alien is an understatement

10:03 am

Worlds without end: Using the space telescope TESS astronomers have determined that one of the hottest exoplanets known, with surface temperatures as much as 7,800 degrees Fahrenheit (hotter than our Sun), is even stranger than expected.

Not only does the exoplanet have a polar orbit around its star, that star rotates so fast that its equator bulges out, actually making its poles as much as 1,500 degrees F hotter than the equator.

With each orbit, KELT-9 b twice experiences the full range of stellar temperatures, producing what amounts to a peculiar seasonal sequence. The planet experiences “summer” when it swings over each hot pole and “winter” when it passes over the star’s cooler midsection. So KELT-9 b experiences two summers and two winters every year, with each season about nine hours.

The star, about 670 light years away, is thought to be twice as massive as the Sun, with the exoplanet having a mass 2.9 times that of Jupiter. Whether it is a gas giant like Jupiter or has an atmosphere is entirely unknown. At these temperatures the situation is so alien we really only know the orbit and approximate range of temperatures.

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Fragment of a long dead planet’s iron core found orbiting white dwarf

8:25 am

Astronomers have identified the fragment of a long dead planet’s iron core orbiting a white dwarf star 410 light years away.

The [data] suggested its source was a solid object some 600 kilometers across—a suspected planetary core, with a density between 7.7 and 39 grams per cubic meter, comparable to the pure iron found within Earth’s core. “The density of the piece of rock is consistent with what we think the cores of planets [are],” says Luca Fossati of the Austrian Academy of Sciences, who was not involved in the paper.

It orbits the star every two hours, the fastest exoplanet orbit yet found. This alone should rip it apart, providing further evidence that the object’s density is very high.

The astronomers theorize that this object is likely the remains of a planet that existed when this star was young, and was destroyed as the star aged to become a red giant, expanding to swallow it. Later, when the star collapsed to become a tiny white dwarf, the core remained, its density allowing it survive as the planet’s outer crust was torn away.

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Rogue giant exoplanet or brown dwarf discovered about 20 light years away

5:16 pm

Using the Jansky VLA radio telescope astronomers have detected evidence of rogue giant exoplanet or brown dwarf about 20 light years away

Astronomers using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) have made the first radio-telescope detection of a planetary-mass object beyond our Solar System. The object, about a dozen times more massive than Jupiter, is a surprisingly strong magnetic powerhouse and a “rogue,” traveling through space unaccompanied by any parent star.

“This object is right at the boundary between a planet and a brown dwarf, or ‘failed star,’ and is giving us some surprises that can potentially help us understand magnetic processes on both stars and planets,” said Melodie Kao, who led this study while a graduate student at Caltech, and is now a Hubble Postdoctoral Fellow at Arizona State University.

The data is not sufficient yet to determine whether this is an exoplanet or a brown dwarf. It is big, and it is floating independent of any other objects, which makes it interesting in of itself.

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Hubble spots a pitch-black exoplanet

9:44 am

Astronomers using the Hubble Space Telescope have determined that an exoplanet is practically pitch black, reflecting almost no light.

NASA’s Hubble Space Telescope has observed a planet outside our solar system that looks as black as fresh asphalt because it eats light rather than reflecting it back into space. This light-eating prowess is due to the planet’s unique capability to trap at least 94 percent of the visible starlight falling into its atmosphere.

The oddball exoplanet, called WASP-12b, is one of a class of so-called “hot Jupiters,” gigantic, gaseous planets that orbit very close to their host star and are heated to extreme temperatures. The planet’s atmosphere is so hot that most molecules are unable to survive on the blistering day side of the planet, where the temperature is 4,600 degrees Fahrenheit. Therefore, clouds probably cannot form to reflect light back into space. Instead, incoming light penetrates deep into the planet’s atmosphere where it is absorbed by hydrogen atoms and converted to heat energy.

Because the exoplanet is tidally locked, with one side always facing its sun and the other always in nightime, the nighttime face is estimated to be about 2,000 degrees cooler, and actually shows evidence of the existence of water vapor and clouds.

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Astronomers find star with giant ringed planet

9:30 am

Astronomers now think that a sunlike star about 1,000 light years away dips in brightness every 2.5 years because an orbiting ringed planet or ringed dwarf star blocks the star’s light.

They discovered that every two and a half years, the light from this distant star – PDS 110 in the Orion constellation, which is same temperature and slightly larger than our sun – is reduced to thirty percent for about two to three weeks. Two notable eclipses observed were in November 2008 and January 2011. “What’s exciting is that during both eclipses we see the light from the star change rapidly, and that suggests that there are rings in the eclipsing object, but these rings are many times larger than the rings around Saturn,” says Leiden astronomer Matthew Kenworthy.

Assuming the dips in starlight are coming from an orbiting planet, the next eclipse is predicted to take place in September this year – and the star is bright enough that amateur astronomers all over the world will be able to witness it and gather new data. Only then will we be certain what is causing the mysterious eclipses.

If confirmed in September, PDS 110 will be the first giant ring system that has a known orbital period. [emphasis in original]

Just so no one is confused, this is not Tabby’s Star. There, the dips in light are seemingly random and follow no pattern, other than an overall dimming for the past century.

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Atmosphere detected around Earth-sized exoplanet

9:00 am

Worlds without end: Astronomers have detected an atmosphere around an Earth-sized exoplanet 39 light years away.

The researchers pored over measurements from the European Southern Observatory in Chile and found that at one wavelength band of light, the planet looked larger than at others, as it crossed the face of its parent star. “These things don’t pop up in the way you expect,” said John Southworth, an astronomer at Keele University in the UK. “We found evidence for the atmosphere at one wavelength band and that wasn’t what we were expecting.”

The observations point to an atmosphere that is rich in water or methane, but it will take more measurements with other telescopes to identify the chemicals present.

The planet is about 16% larger than Earth. There remain a lot of uncertainty here with this result, so we should not yet take it too seriously.

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Earthlike exoplanet discovered orbiting the nearest star

10:54 am

Worlds without end: An Earthlike exoplanet has been discovered in the habitable zone and orbiting Proxima Centauri, the nearest star to the Sun.

The CBC/AP story above doesn’t give many details, mainly because this story is breaking the Thursday embargo, when the actual science paper will be released. Expect a lot more news stories then about this, which probably ranks as one of the biggest science discoveries in history.

Since the embargo is broken, here are some facts from one of the press releases:

The planet, called Proxima b, orbits its parent star every 11 days and has a temperature suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth, and is the closest planet outside our solar system. Planets around other stars are commonly referred to as exoplanets.

…Although Proxima b orbits much closer to its star than Mercury does to the Sun in the solar system, the star itself is far fainter than the sun. As a result Proxima b lies well within the habitable zone around the star and has an estimated surface temperature that would allow the presence of liquid water. Despite the temperate orbit of Proxima b, the conditions on the surface may be strongly affected by the ultraviolet and X-ray flares from the star — these would be far more intense than those the Earth experiences from the Sun.

They first had a hint of the planet’s existence in 2013 (which explains the unsourced rumors I’ve heard periodcally in the past few years about a exoplanet around Proxima Centauri) and spent the past two-plus years making absolutely sure they understood their data.

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Earth forming around sun-like star?

9:51 am

proto-planetary disk

Worlds without end: The ground-based telescope ALMA has imaged a proto-planetary disk around a sun-like star that suggests an exoEarth is forming there the same distance from the star as our Earth is from our Sun.

The star, TW Hydrae, is a popular target of study for astronomers because of its proximity to Earth (approximately 175 light-years away) and its status as a veritable newborn (about 10 million years old). It also has a face-on orientation as seen from Earth. This affords astronomers a rare, undistorted view of the complete disk. “Previous studies with optical and radio telescopes confirm that this star hosts a prominent disk with features that strongly suggest planets are beginning to coalesce,” said Sean Andrews with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author on a paper published today in Astrophysical Journal Letters. “The new ALMA images show the disk in unprecedented detail, revealing a series of concentric dusty bright rings and dark gaps, including intriguing features that suggest a planet with an Earth-like orbit is forming there.”

Other pronounced gap features are located 3 billion and 6 billion kilometers from the central star, similar to the distances from the Sun to Uranus and Pluto in our own Solar System.

The image above right is the inner section of that disk, showing the gap at one astronomical unit, or about 100 million miles from the star, the same as the distance of the Earth from the Sun. Essentially, this relatively close star system is providing us a perfect opportunity to study the formation of a solar system not unlike our own.

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The first image of a newly formed exoplanet

9:45 pm

Astronomers have captured the first image, using ground-based telescopes, of an exoplanet in the process of forming.

The star is 450 light years away, and the image is really a combined image using data taken by two different telescopes, one in infrared light and the other gathering visible light spectroscopy. So, this really isn’t a photograph like you’d take with your camera, but a re-creation. Nonetheless it provides us a first look at the star and the new planet forming in orbit around it.

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Astronomers measure 5,400 mph winds on exoplanet

8:55 am

Category 5! Astronomers have for the first time measured wind speeds on an exoplanet and they are a doozy!

Discovered on the exoplanet HD 189733b, the Warwick researchers measured the velocities on the two sides of HD 189733b and found a strong wind moving at over 5400 mph blowing from its dayside to its night side. Mr Louden explains: “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.”.

This exoplanet was one of the first discovered by Kepler, which means its orbit transits its sun. In this case it does so every 2.2 days, and astronomers have taken advantage of these frequent transits to study the planet’s atmosphere as the star’s light travels through it. The result is that HD 187733b is probably one of the most studied exoplanets.

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