Extrasolar Planets Archives

May 14, 2014December 23, 2015 by David Dickinson

Direct Image of an Exoplanet 155 Light Years Away

Chalk up another benchmark in the fascinating and growing menagerie of extra-solar planets.

This week, an international team of researchers from the Université de Montréal announced the discovery of an exoplanet around the star GU Piscium in the constellation of Pisces the Fishes 155 light years distant. Known as GU Psc b, this world is estimated to be 11 times the mass of Jupiter — placing it just under the lower mass limit for brown dwarf status — and orbits its host star 2,000x farther than the distance from Earth to the Sun once every 80,000 (!) years. In our own solar system, that would put GU Psc b out over twice the distance of the aphelion of 90377 Sedna.

The primary star, GU Psc A, is an M3 red dwarf weighing in at 35% the mass of our Sun and is just 100 million years old, give or take 30 million years. In fact, researchers targeted GU Psc after it was determined to be a member of the AB Doradus moving group of relatively young stars, which are prime candidates for exoplanet detection. Another recent notable discovery, the free-floating “rogue planet” CFBDSIR 2149-0403 is also thought to be a member of the AB Doradus moving group.

The fact that GU Psc B was captured by direct imaging at 155 light years distant is amazing. The international team that made the discovery was led by PhD student at the Department of Physics Université de Montréal Marie-Ève Naud. The team was able to discern this curious planet by utilizing observations from the W.M. Keck observatory, the joint Canada-France-Hawaii Telescope, the Gemini Observatory and the Observatoire Mont-Mégantic in Québec.

Universe Today recently caught up with researcher Marie-Ève Naud and her co-advisor Étienne Artigau about this exciting discovery.

What makes this discovery distinctive? Is this the most distant exoplanet ever imaged?

“Well, first, there are not a lot of exoplanets that were detected ‘directly’ so far. Most were found indirectly through the effect they have on their parent star. The few planets for which we have an actual image are interesting because we can analyze their light directly, and thus learn much more about them. It was also one of the “coolest” planets that have been directly imaged, showing methane absorption. And yes, it is certainly the most distant exoplanet to a main-sequence star that has been found so far.

This distance makes GU Psc b very interesting from a theoretical point of view, because it’s hard to imagine how it could have formed in the protoplanetary disk of its star. The current working definition of an exoplanet is based solely on mass (<13 Jupiter masses), so GU Psc b probably formed in a way that is more similar to how stars formed. It is definitely the kind of object that makes us think about what exactly is an exoplanet.”

At a distance of 2000 A.U.s from its primary, how are astronomers certain that PU Psc b is related to its host and not a foreground or background object?

“As the host star, GU Psc is relatively nearby; it displays a significant apparent proper motion (note: around 100 milliarcseconds a year) relative to distant background stars and galaxies.

On images taken one year apart with WIRCam on the Canada-France-Hawaii Telescope, we observed that the companion displays the same big proper motion, i.e. they move together in the plane of the sky, while the rest of the stars in the field don’t. We also determined the distance of the both the planet and the host star, and they both agree. Also, they both display signs that they are very young.”

Were any groundbreaking techniques used for the discovery, and what does this mean for the future of exoplanet science?

“Quite the opposite… most planet hunting techniques using direct imaging involve state-of-the-art adaptive optics systems, but we used ‘standard’ imaging without any exotic techniques. Planet searches usually attempt to find planets in orbits similar to those of our own solar system giants, and finding these objects, indeed, requires groundbreaking techniques. In a sense, there is an anthropocentric bias in the searches for exoplanets, as people tend to look for systems that are similar to our own solar system. Very distant planets like GU Psc b have been under the radar, even though they are easier to find than their closer-in counterparts. To find this planet, we used very sensitive ‘standard’ imaging, but we chose carefully the wavelengths where planets display colors that are unlike most other astrophysical objects such as stars and galaxies.”

The general field of PU Piscium A & B in the night sky... note that this currently puts it in the dawn sky, near Venus and Uranus! Credit: Starry Night. — The general field of GU Piscium A & B in the night sky… note that this currently puts it in the dawn sky, near Venus and Uranus! Credit: Starry Night.

GU Piscium shines at magnitude +13.6 northeast of the March equinoctial point in the constellation of Pisces. Although its exoplanet companion is too faint to be seen with a backyard telescope, its angular separation is a generous 42,” about the apparent span of Saturn, complete with rings. And it’s shaping up to be a red dwarf sort of week at Universe Today, with our recent list of red dwarf stars for backyard telescopes. And the current tally for extra-solar planets sits at 1,791… hey; didn’t we just pass 1,000 last year?

Congrats to Marie-Ève Naud and her team on this exciting new discovery… and here’s to many more to come!

Read the original paper, Discovery of a Wide Planetary-Mass Companion to the Young M3 Star GU Psc.

May 13, 2014December 23, 2015 by David Dickinson

14 Red Dwarf Stars to View with Backyard Telescopes

An artist's conception of a red dwarf solar system. Credit: NASA/JPL-Caltech.

They’re nearby, they’re common and — at least in the latest exoplanet newsflashes hot off the cyber-press — they’re hot. We’re talking about red dwarf stars, those “salt of the galaxy” stars that litter the Milky Way. And while it’s true that there are more of “them” than there are of “us,” not a single one is bright enough to be seen with the naked eye from the skies of Earth.

A reader recently brought up an engaging discussion of what red dwarfs might be within reach of a backyard telescope, and thus this handy compilation was born.

Of course, red dwarfs are big news as possible hosts for life-bearing planets. Though the habitable zones around these stars would be very close in, these miserly stars will shine for trillions of years, giving evolution plenty of opportunity to do its thing. These stars are, however, tempestuous in nature, throwing out potentially planet sterilizing flares.

Red dwarf stars range from about 7.5% the mass of our Sun up to 50%. Our Sun is very nearly equivalent 1000 Jupiters in mass, thus the range of red dwarf stars runs right about from 75 to 500 Jupiter masses.

For this list, we considered red dwarf stars brighter than +10^th magnitude, with the single exception of 40 Eridani C as noted.

The closest stars within 14 light years of our solar system. Credit: Wikimedia Commons, Public Domain graphic.

I know what you’re thinking… what about the closest? At magnitude +11, Proxima Centauri in the Alpha Centauri triple star system 4.7 light years distant didn’t quite make the cut. Barnard’s Star (see below) is the closest in this regard. Interestingly, the brown dwarf pair Luhman 16 was discovered just last year at 6.6 light years distant.

Also, do not confuse red dwarfs with massive carbon stars. In fact, red dwarfs actually appear to have more of an orange hue visually! Still, with the wealth of artist’s conceptions (see above) out there, we’re probably stuck with the idea of crimson looking red dwarf stars for some time to come.

Star	Magnitude	Constellation	R.A.	Dec
Groombridge 34	+8/11(v)	Andromeda	00h 18’	+44 01’
40 Eridani C	+11	Eridanus	04h 15’	-07 39’
AX Microscopii/Lacaille 8760	+6.7	Microscopium	21h 17’	-38 52’
Barnard’s Star	+9.5	Ophiuchus	17h 58’	+04 42’
Kapteyn’s Star	+8.9	Pictor	05h 12’	-45 01’
Lalande 21185	+7.5	Ursa Major	11h 03’	+35 58’
Lacaille 9352	+7.3	Piscis Austrinus	23h 06’	-35 51’
Struve 2398	+9.0	Draco	18h 43’	+59 37’
Luyten’s Star	+9.9	Canis Minor	07h 27’	+05 14’
Gliese 687	+9.2	Draco	17h 36’	+68 20’
Gliese 674	+9.9	Ara	17h 29’	-46 54’
Gliese 412	+8.7	Ursa Major	11h 05’	+43 32’
AD Leonis	+9.3	Leo	10h 20’	+19 52’
Gliese 832	+8.7	Grus	21h 34’	-49 01’

Notes on each:

Groombridge 34: Located less than a degree from the +6th magnitude star 26 Andromedae in the general region of the famous galaxy M31, Groombridge 34 was discovered back in 1860 and has a large proper motion of 2.9″ arc seconds per year.

Locating Groombridge 34. Created using Stellarium.

40 Eridani C: Our sole exception to the “10^th magnitude or brighter” rule for this list, this multiple system is unique for containing a white dwarf, red dwarf and a main sequence K-type star all within range of a backyard telescope. In sci-fi mythos, 40 Eridani is also the host star for the planet Richese in Dune and the controversial location for Vulcan of Star Trek fame.

Locating 40 Eridani. Created using Stellarium.

AX Microscopii: Also known as Lacaille 8760, AX Microscopii is 12.9 light years distant and is the brightest red dwarf as seen from the Earth at just below naked eye visibility at magnitude +6.7.

A 20 year animation showing the proper motion of Barnard's Star. Credit: Steve Quirk, images in the Public Domain. — A 20 year animation showing the proper motion of Barnard’s Star. Credit: Steve Quirk, images in the Public Domain.

Barnard’s Star: the second closest star system to our solar system next to Alpha Centuari and the closest solitary red dwarf star at six light years distant, Barnard’s Star also exhibits the highest proper motion of any star at 10.3” arc seconds per year. The center of many controversial exoplanet claims in the 20^th century, it’s kind of a cosmic irony that in this era of 1790 exoplanets and counting, planets have yet to be discovered around Barnard’s Star!

Kapteyn’s Star: Discovered by Jacobus Kapteyn in 1898, this red dwarf orbits the galaxy in a retrograde motion and is the closest halo star to us at 12.76 light years distant.

Lalande 21185: currently 8.3 light years away, Lalande 21185 will pass 4.65 light years from Earth and be visible to the naked eye in just under 20,000 years.

Lacaille 9352: 10.7 light years distant, this was the first red dwarf star to have its angular diameter measured by the VLT interferometer in 2001.

Struve 2398: A binary flare star system consisting of two +9^th magnitude red dwarfs orbiting each other 56 astronomical units apart and 11.5 light years distant.

Luyten’s Star: 12.36 light years distant, this star is only 1.2 light years from the bright star Procyon, which would appear brighter than Venus for any planet orbiting Luyten’s Star.

Gliese 687: 15 light years distant, Gliese 687 is known to have a Neptune-mass planet in a 38 day orbit.

Gliese 674: Located 15 light years distant, ESO’s HARPS spectrograph detected a companion 12 times the mass of Jupiter that is either a high mass exoplanet or a low mass brown dwarf.

Gliese 412: 16 light years distant, this system also contains a +15^th magnitude secondary companion 190 Astronomical Units from its primary.

AD Leonis: A variable flare star in the constellation Leo about 16 light years distant.

Gliese 832: Located 16 light years distant, this star is known to have a 0.6x Jupiter mass exoplanet in a 3,416 day orbit.

The closest stars to our solar system over the next 80,000 years. Credit: FrancescoA under a Creative Commons Attribution Share-Alike 3.0 Unported license.

Consider this list a teaser, a telescopic appetizer for a curious class of often overlooked objects. Don’t see you fave on the list? Want to see more on individual objects, or similar lists of quasars, white dwarfs, etc in the range of backyard telescopes in the future? Let us know. And while it’s true that such stars may not have a splashy appearance in the eyepiece, part of the fun comes from knowing what you’re seeing. Some of these stars have a relatively high proper motion, and it would be an interesting challenge for a backyard astrophotographer to build an animation of this over a period of years. Hey, I’m just throwing that out project out there, we’ve got lots more in the files…

April 30, 2014December 23, 2015 by Elizabeth Howell

Spin! Exoplanet’s Day Finishes Blazing Fast Compared To Earth

Artist's impression of Beta Pictoris b. Credit: ESO L. Calçada/N. Risinger (skysurvey.org)

Between the time you got to work this morning and the time you leave today — assuming an eight-hour work cycle — an entire day will have passed on Beta Pictoris b, according to new measurements of the exoplanet.

This daily cycle, mapped for the first time on a planet outside of the solar system, may reveal a link between how big a planet is and how fast it rotates, astronomers stated. That said, caution is needed because there are only a handful of planets where the rotation is known: the eight planets of our Solar System and Beta Pictoris b.

The planet’s day is shorter than any other planet in our Solar System, which at first blush makes sense because the planet is also larger than any other planet in our Solar System. Beta Pictoris b is estimated at 16 times larger and 3,000 times more massive than Earth. (For comparison, Jupiter is about 11 times larger and 318 times more massive than Earth.)

“It is not known why some planets spin fast and others more slowly,” stated says co-author Remco de Kok, “but this first measurement of an exoplanet’s rotation shows that the trend seen in the Solar System, where the more massive planets spin faster, also holds true for exoplanets. This must be some universal consequence of the way planets form.”

Planets in our Solar system size comparison. Largest to smallest are pictured left to right, top to bottom: Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury. Via Wikimedia Commons. — Planets in our Solar system size comparison.
Largest to smallest are pictured left to right, top to bottom: Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury. Via Wikimedia Commons.

Astronomers mapped the planet’s equatorial rotation using the CRIRES instrument on the Very Large Telescope. What helped was not only the planet’s large size, but also its proximity to Earth: it’s about 63 light-years away, which is relatively close to us.

As the planet ages (it’s only 20 million years old right now) it is expected to shrink and spin more quickly, assuming no other external forces. The Earth’s rotation is slowed by the moon, for example.

The study (“Fast spin of a young extrasolar planet” will soon be up on Nature’s website and was led by Leiden University’s Ignas Snellen.

Source: European Southern Observatory

April 28, 2014December 23, 2015 by Elizabeth Howell

What Steps Are Needed To Find More Earths?

Artist's rendering of Kepler-186f (Credit: NASA Ames/SETI Institute/Caltech)

It wasn’t so long ago that we found out there is an Earth-sized planet in a habitable zone of a star. But how many others are out there, and do we know if planets like this are truly habitable?

“Looking towards the future, what we really want to do eventually is transform our knowledge from planets in the habitable zone to [characterizing] planetary environments,” said Natalie Batalha, a co-investigator on NASA’s Kepler Space Telescope, in a webcast presentation today (April 28) .

This means that astronomers will be able to, from a distance, look at “biosignatures” of life in the atmosphere. What a biosignature would be is still being characterized, but it could be something like an unusually high proportion of oxygen — as long as abiotic processes are not accounted for, of course.

Batalha identified these parameters for finding other Earths in a presentation at the “Habitable Worlds Across Time and Space” conference presented by the Space Telescope Science Institute:

Detections of planets: other telescopes (left) vs. Kepler. Credit: Natalie Batalha / NASA (screenshot) — Detections of planets in the habitable zone: other telescopes (left) vs. the Kepler space telescope. Credit: Natalie Batalha / NASA (screenshot)

– The telescope must be sensitive to an Earth-sized planet in the habitable zone of a G, K or M-type star (which are stars that are like the sun);

– A uniform and reliable detection catalog with well-understood sizes, orbital periods and insolation fluxes (energy received from the sun);

– Knowledge of Kepler’s detection efficiency and the planetary catalog’s reliability;

– Well-documented and accessible data products for other community members to analyze.

What would also be helpful to planetary scientists is learning more about how a planet forms in the habitable region of its star.

In a presentation at the same conference, the University of Toronto’s Diana Valencia (an astrophysicist) pointed out there is no single predictor for how large a planet will get. It depends on how close a planetesimal disc is to its star, the rate of accretion in the area and dust opacity, among other factors.

She also gave a brief overview of processes that demonstrate how hard it is to predict habitability. Earth had at least two atmospheres in its past, presentation slides said, with the first atmosphere lost and the second built from volcanism and impacts. Valencia also pointed to complexities involving the Earth’s mantle and plate tectonics.

The University of Puerto Rico keeps a list of potentially habitable planets on its website, which as of this writing stands at 21.

The conference runs through May 1, and you can see the agenda here.

April 24, 2014December 23, 2015 by Nancy Atkinson

Take a Fly-by Of All the Known Exoplanets

This bubble chart shows the relative sizes of all discovered planets. The color corresponds to the mean equilibrium temperature of the planet. Click to interact on the Open Exoplanet Catalogue website.

Here’s a fun trip through the galaxy, put together by PhD student Tom Hands at the University of Leicester: In the above video, you can fly to of all the known exoplanets (around single stars only), ordered roughly by semi-major axis of largest orbit. Hands said the video is designed to give the viewer an overview of the current distribution of exoplanets.

Hands used data from the Open Exoplanet Catalogue.

April 17, 2014December 23, 2015 by Jason Major

Kepler Has Found the First Earth-Sized Exoplanet in a Habitable Zone!

It’s truly a “eureka” moment for Kepler scientists: the first rocky Earth-sized world has been found in a star’s habitable “Goldilocks” zone, the narrow belt where liquid water could readily exist on a planet’s surface without freezing solid or boiling away. And while it’s much too soon to tell if this really is a “twin Earth,” we can now be fairly confident that they do in fact exist.

The newly-confirmed extrasolar planet has been dubbed Kepler-186f. It is the fifth and outermost planet discovered orbiting the red dwarf star Kepler-186, located 490 light-years away. Kepler-186f completes one orbit around its star every 130 days, just within the outer edge of the system’s habitable zone.

The findings were made public today, April 17, during a teleconference hosted by NASA.

“This is the first definitive Earth-sized planet found in the habitable zone around another star,” says lead author Elisa Quintana of the SETI Institute at NASA Ames Research Center. “Finding such planets is a primary goal of the Kepler space telescope. The star is a main-sequence M-dwarf, a very common type. More than 70 percent of the hundreds of billions of stars in our galaxy are M-dwarfs.”

A visualization of the “unseen” red dwarfs in the night sky. Credit: D. Aguilar & C. Pulliam (CfA) — A visualization of the many “unseen” red dwarfs in the night sky. (CLICK FOR ANIMATION) Credit: D. Aguilar & C. Pulliam (CfA)

Unlike our Sun, which is a G-type yellow dwarf, M-dwarf stars (aka red dwarfs) are much smaller and dimmer. As a result their habitable zones are much more confined. But, being cooler stars, M-dwarfs have long lifespans, offering planets in their habitable zones — like Kepler-186f — potentially plenty of time to develop favorable conditions for life.

In addition, M-dwarfs are the most abundant stars in our galaxy; 7 out of 10 stars in the Milky Way are M-dwarfs, although most can’t be seen by the naked eye. Finding an Earth-sized planet orbiting one relatively nearby has enormous implications in the hunt for extraterrestrial life.

“M dwarfs are the most numerous stars,” said Quintana. “The first signs of other life in the galaxy may well come from planets orbiting an M dwarf.”

Still, there are many more conditions on a planet that must be met for it to be actually habitable. But size, composition, and orbital radius are very important first steps.

“Some people call these habitable planets, which of course we have no idea if they are,” said Stephen Kane, an assistant professor of physics and astronomy at San Francisco State University in California. “We simply know that they are in the habitable zone, and that is the best place to start looking for habitable planets.”

Scale comparison of the Kepler-186 system to our inner Solar System ( — Scale comparison of the Kepler-186 system and the inner Solar System (NASA Ames/SETI Institute/Caltech)

As far as the planetary system’s age is concerned — which relates to how long life could have potentially had to evolve on Kepler-186f’s surface — that’s hard to determine… especially with M-dwarf stars. Because they are so stable and long-lived, once they’re formed M-dwarfs essentially stay the same throughout their lifetimes.

“We know it’s probably older than a few billion years, but after that it’s very difficult to tell,” BAERI/Ames scientist Tom Barclay told Universe Today. “That’s the problem with M-dwarfs.”

A comparison of the Kepler 186 and Solar systems (NASA/Ames) — A comparison of the Kepler 186 and Solar systems (Presentation slide, NASA/Ames)

The exoplanet was discovered via the transit method used by NASA’s Kepler spacecraft, whereby stars’ brightnesses are continually monitored within a certain field of view. Any dips in luminance reveal the likely presence of a passing planet.

Because of its small size — just slightly over 1 Earth radius — and close proximity to its star, Kepler-186f can’t be observed directly with current telescope technology.

The Gemini North telescope on the summit of Mauna Kea (Gemini Observatory/AURA)

“However, what we can do is eliminate essentially all other possibilities so that the validity of these planets is really the only viable option,” said Steve Howell, Kepler project scientist and a co-author on the paper.

Using the latest advanced imaging capabilities of the Gemini North and Keck II observatories located atop Mauna Kea in Hawaii, astronomers were able to determine that the signals detected by Kepler were from a small orbiting planet and not something else, such as a background or companion star.

“The Keck and Gemini data are two key pieces of this puzzle,” Quintana said. “Without these complementary observations we wouldn’t have been able to confirm this Earth-sized planet.”

Kepler-186f joins the other 20 extrasolar worlds currently listed in the Habitable Exoplanets Catalog, maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. To date 961 exoplanets have been confirmed through Kepler observations, with 1,696 total confirmed altogether. (Source)

Artist's conception of the Kepler Space Telescope. Credit: NASA/JPL-Caltech — Artist’s conception of the Kepler Space Telescope. Credit: NASA/JPL-Caltech

Whether Kepler-186f actually resembles Earth or not, this discovery provides more information on the incredible variety of planetary systems to be found even in our little corner of the galaxy.

“The diversity of these exoplanets is one of the most exciting things about the field,” Kane said. “We’re trying to understand how common our solar system is, and the more diversity we see, the more it helps us to understand what the answer to that question really is.”

The SETI Institute’s Allen Telescope Array has surveyed the Kepler-186 system for any potential signals but so far none has been detected. Further observations are planned.

“Kepler-186f is special because we already know that a planet of its size and distance is capable of supporting life.”
– Elisa Quintana, research scientist, SETI Institute

The team’s paper, “An Earth-sized Planet in the Habitable Zone of a Cool Star” by Elisa V. Quintana et al., will be published in the April 18 issue of Science.

Learn more about the Kepler mission here, and read more about this discovery in NASA’s news release here and on the W.M. Keck website here.

Watch some video excerpts of team interviews and data renderings below:

Also, you can download the slides used in the NASA teleconference here.

Sources: San Francisco State University, Gemini Observatory, W.M. Keck Observatory, and SETI news releases

March 13, 2014April 26, 2016 by David Dickinson

“Death Stars” Caught Blasting Proto-Planets

It’s a tough old universe out there. A young star has lots to worry about, as massive stars just beginning to shine can fill a stellar nursery with a gale of solar wind.

No, it’s not a B-movie flick: the “Death Stars of Orion” are real. Such monsters come in the form of young, O-type stars.

And now, for the first time, a team of astronomers from Canada and the United States have caught such stars in the act. The study, published in this month’s edition of The Astrophysical Journal, focused on known protoplanetary disks discovered by the Hubble Space Telescope in the Orion Nebula.

These protoplanetary disks, also known as “tadpoles” or proplyds, are cocoons of dust and gas hosting stars just beginning to shine. Much of this leftover material will go on to aggregate into planets, but nearby massive O-Type stars can cause chaos in a stellar nursery, often disrupting the process.

“O-Type stars, which are really monsters compared to our Sun, emit tremendous amounts of ultraviolet radiation and this can play havoc during the development of young planetary systems,” said astronomer Rita Mann in a recent press release. Mann works for the National Research Council of Canada in Victoria and is lead researcher on the project

Scientists used the Atacama Large Millimeter Array (ALMA) to probe the proplyds of Orion in unprecedented detail. Supporting observations were also made using the Submillimeter Array in Hawaii.

ALMA saw “first light” in 2011, and has already achieved some first rate results.

“ALMA is the world’s most sensitive telescope at high-frequency radio waves (e.g., 100-1000 GHz). Even with only a fraction of its final number of antennas, (with 22 operational out of a total planned 50) we were able to detect with ALMA the disks relatively close to the O-star while previous observatories were unable to spot them,” James Di Francesco of the National Research Council of Canada told Universe Today. “Since the brightness of a disk at these frequencies is proportional to its mass, these detections meant we could measure the masses of the disks and see for sure that they were abnormally low close to the O-type star.”

ALMA also doubled the number of proplyds seen in the region, and was also able to peer within these cocoons and take direct mass measurements. This revealed mass being stripped away by the ultraviolet wind from the suspect O-type stars. Hubble had been witness to such stripping action previous, but ALMA was able to measure the mass within the disks directly for the first time.

And what was discovered doesn’t bode well for planetary formation. Such protostars within about 0.1 light-years of an O-type star are consigned to have their cocoon of gas and dust stripped clean in just a few million years, just a blink of a eye in the game of planetary formation.

With a O-type star’s “burn brightly and die young” credo, this type of event may be fairly typical in nebulae during early star formation.

“O-type stars have relatively short lifespan, say around 1 million years for the brightest O-star in Orion – which is 40 times the mass of our Sun – compared to the 10 billion year lifespan of less massive stars like our Sun,” Di Francesco told Universe Today. “Since these clusters are typically the only places where O-stars form, I’d say that this type of event is indeed typical in nebulae hosting early star formation.”

It’s common for new-born stars to be within close proximity of each other in such stellar nurseries as M42. Researchers in the study found that any proplyds within the extreme-UV envelope of a massive star would have its disk shredded in short order, retaining on average less than 50% the mass of Jupiter total. Beyond the 0.1 light year “kill radius,” however, the chances for these proplyds to retain mass goes up, with researchers observing anywhere from 1 to 80 Jupiter masses of material remaining.

The findings in this study are also crucial in understanding what the early lives of stars are like, and perhaps the pedigree of our own solar system, as well as how common – or rare – our own history might be in the story of the universe.

There’s evidence that our solar system may have been witness to one or more nearby supernovae early in its life, as evidenced by isotopic measurements. We were somewhat lucky to have had such nearby events to “salt” our environment with heavy elements, but not sweep us clean altogether.

“Our own Sun likely formed in a clustered environment similar to that of Orion, so it’s a good thing we didn’t form too close to the O-stars in its parent nebula,” Di Francesco told Universe Today. “When the Sun was very young, it was close enough to a high-mass star so that when it blew up (went supernova) the proto-solar system was seeded with certain isotopes like Al-26 that are only produced in supernova events.”

This is the eventual fate of massive O-type stars in the Orion Nebula, though none of them are old enough yet to explode in this fashion. Indeed, it’s amazing to think that peering into the Orion Nebula, we’re witnessing a drama similar to what gave birth to our Sun and solar system, billions of years ago.

The Orion Nebula is the closest active star forming region to us at about 1,500 light years distant and is just visible to the naked eye as a fuzzy patch in the pommel of the “sword” of Orion the Hunter. Looking at the Orion Nebula at low power through a small telescope, you can just make out a group of four stars known collectively as the Trapezium. These are just such massive hot and luminous O-Type stars, clearing out their local neighborhoods and lighting up the interior of the nebula like a Chinese lantern.

And thus science fact imitates fiction in an ironic twist, as it turns out that “Death Stars” do indeed blast planets – or at least protoplanetary disks – on occasion!

Be sure to check out a great piece on ALMA on a recent episode of CBS 60 Minutes:

Read the abstract and the full (paywalled) paper on ALMA Observations of the Orion Proplyds in The Astrophysical Journal.

March 7, 2014December 23, 2015 by Elizabeth Howell

Giant Planet May Be Lurking In ‘Poisonous’ Gas Around Beta Pictoris

Artist's conception of a hypothetical giant planet (left) in Beta Pictoris. The gas giant would sweep up comets into a swarm, causing frequent collisions. Astronomers using the Atacama Large Millimeter Array (ALMA) are calling this the "preferred model" for observations they made. Credit: Goddard Space Flight Center/F. Reddy

A Saturn-mass planet might be lurking in the debris surrounding Beta Pictoris, new measurements of a debris field around the star shown. If this could be proven, this would be the second planet found around that star.

The planet would be sheparding a giant swarm of comets (some in front and some trailing behind the planet) that are smacking into each other as often as every five minutes, new observations with the Atacama Large Millimeter/submillimeter Array (ALMA) show. This is the leading explanation for a cloud of carbon monoxide gas visible in the array.

“Although toxic to us, carbon monoxide is one of many gases found in comets and other icy bodies,” stated Aki Roberge, an astrophysicist at NASA’s Goddard Space Flight Center in Maryland who participated in the research. “In the rough-and-tumble environment around a young star, these objects frequently collide and generate fragments that release dust, icy grains and stored gases.”

ALMA captured millimeter-sized light from carbon monoxide and dust around Beta Pictoris, which is about 63 light-years from Earth (relatively close to our planet). The gas seems to be most prevalent in an area about 8 billion miles (13 kilometers) from the star — the equivalent distance of three times the length of Neptune’s location from the sun. The carbon monoxide cloud itself makes up about one-sixth the mass of Earth’s oceans.

Ultraviolet light from the star should be breaking up the carbon monoxide molecules within 100 years, so the fact there is so much gas indicates something must be replenishing it, the researchers noted. Their models showed that the comets would need to be destroyed every five minutes for this to happen (unless we are looking at the star at an unusual time).

While the researchers say they need more study to see how the gas is concentrated, their hypothesis is there is two clumps of gas and it is due to a big planet behaving similarly to what Jupiter does in our solar system. Thousands of asteroids follow behind and fly in front of Jupiter due to the planet’s massive gravity. In this more distant system, it’s possible that a gas giant planet would be doing the same thing with comets.

If the gas turns out to be in just one clump, however, another scenario would suggest two Mars-sized planets (icy ones) smashing into each other about half a million years ago. This “would account for the comet swarm, with frequent ongoing collisions among the fragments gradually releasing carbon monoxide gas,” NASA stated.

The research was published yesterday (March 6) in the journal Science and is led by Bill Dent, a researcher at the Joint ALMA Office in Chile. You can read more information in press releases from NASA, the National Radio Astronomy Observatory and European Southern Observatory.

February 26, 2014December 23, 2015 by Elizabeth Howell

Mega Discovery! 715 Alien Planets Confirmed Using A New Trick On Old Kepler Data

Planet-watchers, some exciting news: you know how we keep talking about planet candidates, those planets that have yet to be confirmed, when we reveal stories about other worlds? That’s because verifying that the slight dimming of a star’s light is due to a planet takes time – -specifically, to have other telescopes verify it through examining gravitational wobbles on the parent star.

Turns out there’s a way to solve the so-called “bottleneck” of planet candidates vs. confirmed planets. NASA has made use of a new technique that they say will work for multi-planet systems, one that already has results: a single Kepler release of data today (Feb. 26) yielded 715 new planets in one shot. That almost doubles the amount of known planets found before today, which was just under 1,000, officials said.

“This is the largest windfall of planets, not exoplanet candidates, but actual verified exoplanets announced at one time,” said Doug Hudgins, a NASA exoplanet exploration program scientist based in Washington, D.C., at a press conference today. What’s more, among the release were four planets (about double to 2.5 times the size of Earth) that could be considered habitable: Kepler-174 d, Kepler-296 f, Kepler-298 d, Kepler-309 c.

The findings were based on scouring the first two of Kepler’s four years of data, so scientists expect there will be a lot more to come once they go through the second half. Most of the discoveries were planets close to Earth’s size, showing that small planets are common in multiplanetary systems.

These planets, however, are crowded into insanely compact multiple planet systems, sometimes within the reaches of the equivalent of Mercury’s or Venus’ orbits. It’s raising questions about how young systems would have enough material in those reaches to form planets. Perhaps planetary migration played a role, but that’s still poorly understood.

Verification by multiplicity is a new method for finding planets in multiple-planet systems. In cases where astronomers see several objects transiting a star in regular orbits, the assumption is it must be planets. A set of stars in a similar configuration would have orbits too unstable for regular transits. Credit: NASA

Discoveries of these worlds was made with a new technique called “verification by multiplicity”. The challenge with the method Kepler uses — watching for starlight dimming when a planet passes in front of it — is there are other ways that same phenomenon can occur. One common reason is if the star being observed is a binary star and the second star is just barely grazing the first.

This is how the technique works: If you can imagine a star with a bunch of other stars around it, the mutual gravities of each object would throw their relative orbits into chaos. A star with a bunch of planets, however, would have a more stable orbital configuration. So if scientists see multiple transits of objects across a star’s face, the assumption is that it would be several planets.

“This physical difference, the fact you can’t have multiple star systems that look like planetary systems, is the basis of the validation by multiplicity,” said Jack Lissauer, a planetary scientist at the NASA Ames Research Center who was involved in the research.

Although this is a new technique, the astronomers said there has been at least one published publication talking about this method, and they added that two papers based on their own research have been accepted for publication in the peer-reviewed Astrophysical Journal.

Sizes of verified planets just after a release of 715 confirmed planets from Kepler data in February 2014. Credit: NASA

There’s been a lot of attention on Kepler lately, not only because of its planetary finds, but also its uncertain status. In May 2013, a second of its four reaction wheels (or gyroscopes) went down, robbing the probe of its primary mission: to seek planets transiting in front of their stars in a spot in the Cygnus constellation. Since then, scientists have been working on a new method of finding planets with the spacecraft.

Called K2, it would essentially use the sun’s photon “push” on the spacecraft as a way to stabilize Kepler long enough to peer at different areas of the sky throughout the year. The mission is now at a senior-level review process and a decision is expected around May this year.

The spacecraft is good to go for K2 physically, NASA added, as the spacecraft only has four major malfunctions: the two reaction wheels, and 2 (out of 21) “science modules” that are used for science observing. The first module failed early in the mission, while the second died during a recent K2 test. While the investigation is ongoing, NASA said that they expect it will be due to an isolated part failure and that it will have no measurable impact on doing K2.

Edit, 8:30 p.m. EST: The two papers related to the Kepler discovery are available here and here on the prepublishing site Arxiv. Both are accepted for publication in the Astrophysical Journal. (Hat tip to Tom Barclay).

February 25, 2014December 23, 2015 by Jason Major

New Technique Finds Water in Exoplanet Atmospheres

Artist's concept of a hot Jupiter exoplanet orbiting a star similar to tau Boötes (Image used with permission of David Aguilar, Harvard-Smithsonian Center for Astrophysics)

As more and more exoplanets are identified and confirmed by various observational methods, the still-elusive “holy grail” is the discovery of a truly Earthlike world… one of the hallmarks of which is the presence of liquid water. And while it’s true that water has been identified in the thick atmospheres of “hot Jupiter” exoplanets before, a new technique has now been used to spot its spectral signature in yet another giant world outside our solar system — potentially paving the way for even more such discoveries.

Researchers from Caltech, Penn State University, the Naval Research Laboratory, the University of Arizona, and the Harvard-Smithsonian Center for Astrophysics have teamed up in an NSF-funded project to develop a new way to identify the presence of water in exoplanet atmospheres.

Previous methods relied on specific instances such as when the exoplanets — at this point all “hot Jupiters,” gaseous planets that orbit closely to their host stars — were in the process of transiting their stars as viewed from Earth.

This, unfortunately, is not the case for many extrasolar planets… especially ones that were not (or will not be) discovered by the transiting method used by observatories like Kepler.

Watch: Kepler’s Universe: More Planets in Our Galaxy Than Stars

So the researchers turned to another method of detecting exoplanets: radial velocity, or RV. This technique uses visible light to watch the motion of a star for the ever-so-slight wobble created by the gravitational “tug” of an orbiting planet. Doppler shifts in the star’s light indicate motion one way or another, similar to how the Doppler effect raises and lowers the pitch of a car’s horn as it passes by.

The two Keck 10-meter domes atop Mauna Kea. (Rick Peterson/WMKO)

But instead of using visible wavelengths, the team dove into the infrared spectrum and, using the Near Infrared Echelle Spectrograph (NIRSPEC) at the W. M. Keck Observatory in Hawaii, determined the orbit of the relatively nearby hot Jupiter tau Boötis b… and in the process used its spectroscopy to identify water molecules in its sky.

“The information we get from the spectrograph is like listening to an orchestra performance; you hear all of the music together, but if you listen carefully, you can pick out a trumpet or a violin or a cello, and you know that those instruments are present,” said Alexandra Lockwood, graduate student at Caltech and first author of the study. “With the telescope, you see all of the light together, but the spectrograph allows you to pick out different pieces; like this wavelength of light means that there is sodium, or this one means that there’s water.”

Previous observations of tau Boötis b with the VLT in Chile had identified carbon monoxide as well as cooler high-altitude temperatures in its atmosphere.

Now, with this proven IR RV technique, the atmospheres of exoplanets that don’t happen to cross in front of their stars from our point of view can also be scrutinized for the presence of water, as well as other interesting compounds.

“We now are applying our effective new infrared technique to several other non-transiting planets orbiting stars near the Sun,” said Chad Bender, a research associate in the Penn State Department of Astronomy and Astrophysics and a co-author of the paper. “These planets are much closer to us than the nearest transiting planets, but largely have been ignored by astronomers because directly measuring their atmospheres with previously existing techniques was difficult or impossible.”

Once the next generation of high-powered telescopes are up and running — like the James Webb Space Telescope, slated to launch in 2018 — even smaller and more distant exoplanets can be observed with the IR method… perhaps helping to make the groundbreaking discovery of a planet like ours.

“While the current state of the technique cannot detect earthlike planets around stars like the Sun, with Keck it should soon be possible to study the atmospheres of the so-called ‘super-Earth’ planets being discovered around nearby low-mass stars, many of which do not transit,” said Caltech professor of cosmochemistry and planetary sciences Geoffrey Blake. “Future telescopes such as the James Webb Space Telescope and the Thirty Meter Telescope (TMT) will enable us to examine much cooler planets that are more distant from their host stars and where liquid water is more likely to exist.”

The findings are described in a paper published in the February 24, 2014 online version of The Astrophysical Journal Letters.

Sources: Caltech and EurekAlert press releases.