“Blue” Exoplanet Now Seen in X-rays for the First Time

This graphic depicts HD 189733b, the first exoplanet caught passing in front of its parent star in X-rays. Credit: X-ray: NASA/CXC/SAO/K.Poppenhaeger et al; Illustration: NASA/CXC/M.Weiss.

In the medical field, X-rays are used for finding and diagnosing all sorts of ailments hidden inside the body; in astronomy X-rays can also be used to study obscured objects like pulsars and black holes. Now, for the first time, X-rays have been used to study another object in space that tends to be difficult to spot: an extra solar planet. The Chandra X-ray Observatory and the XMM Newton Observatory combined their X-ray super powers to look at an exoplanet passing in front of its parent star.

This is not a new detection of an exoplanet – this same exoplanet, named HD 189733b has been one of the most-observed planets orbiting another star, and was recently in the news for Hubble confirming the planet’s ocean-blue atmosphere and the likelihood of having glass raining down on the planet.

But being able to see the exoplanet in X-rays is good news for future studies and perhaps even detections of planets around other stars.

“Thousands of planet candidates have been seen to transit in only optical light,” said Katja Poppenhaeger of Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., who led the new study, which will be published in the Aug. 10 edition of The Astrophysical Journal. “Finally being able to study one in X-rays is important because it reveals new information about the properties of an exoplanet.”

Artist’s impression of the deep blue planet HD 189733b, based on observations from the Hubble Space Telescope. Credit: NASA/ESA.
Artist’s impression of the deep blue planet HD 189733b, based on observations from the Hubble Space Telescope. Credit: NASA/ESA.

HD 189733b is a Jupiter-sized extrasolar planet orbiting a yellow dwarf star that is in a binary system called HD 189733 in the constellation of Vulpecula, near the Dumbell Nebula, approximately 62 light years from Earth.

This huge gas giant orbits very close to its host star and gets blasted with X-rays from its star — tens of thousands of times stronger than the Earth receives from the Sun — and endures wild temperature swings, reaching scorching temperatures of over 1,000 degrees Celsius. Astronomers say it likely rains glass (silicates) – sideways — in howling 7,000 kilometer-per-hour winds.

But it is relatively close to Earth, and so it has been oft-studied by many other space and ground-based telescopes.

In a blog post, Poppenhaeger said she was inspired by the launch of the Kepler telescope, and wondered if exoplanets could be seen in X-rays. She was excited when she found archived data from XMM Newton showing a fifteen hour long observation of the star HD 189733 and the “Hot Jupiter” HD 189733b was crossing in front of the star during that observation.

But the light curve was disappointing, she said. “The star is magnetically active, meaning that its corona is bright and flickering, so its X-ray light curve showed lots of scatter. Looking for a transit signal in this light curve was like trying to hear a whisper in a noisy pub,” Poppenhaeger wrote.

She knew with more data, the transit signal would be clearer, so she applied for – and got – time on Chandra to observe this exoplanet.

She combined the data from all the observations and was finally successful. “I could detect the transit of the planet in X-rays,” Poppenhaeger said. “What surprised me was how deep the transit was: The planet swallowed about 6-8% of the X-ray light from the star, while it only blocked 2.4% of the starlight at optical wavelengths. That means that the planet’s atmosphere blocks X-rays at altitudes of more than 60,000 km above its optical radius – a 75% larger radius in X-rays!”

That means that the outer atmosphere has to be heated up to about 20,000 K to sustain itself at such high altitudes. Additionally, the planet loses its atmosphere about 40% faster than thought before.

Poppenhaeger said she and her colleagues will test more X-ray observations of other similar planets such as CoRoT-2b to learn more about how stars can affect a planet’s atmosphere.

Read the paper here.

Sources: Chandra, Chandra Blog.

Virtual Star Party – July 28, 2013

In case you missed it live, here was our Virtual Star Party for Sunday, July 28, 2013. We had two active telescopes going, but they were highly automated scopes slewing from target to target with precise efficiency. We probably hit a new record this week, with the number of objects we targeted. We had nebulae, galaxies, star clusters and special appearances from Neptune… and Pluto; our first of the season!

Host: Fraser Cain

Astronomers: Gary Gonella, Louis Mamakos

Commentary: Dr. Thad Szabo, Stuart Forman

We get together every Sunday night for a Virtual Star Party in a live Google+ Hangout on Air. You can watch live, and ask your questions about astronomy and astrophotography; we’ll even take requests.

We’ll broadcast the video live from here on Universe Today, or over on Google+.

If you’re an astronomer and have the ability to view images from your telescope on your computer, we’d love to have you join us some week. Especially if you live in Europe or South America.

Alan Parson’s Project Dedicates Song to ISS Astronaut Parmitano

When we heard that the Alan Parsons Project song “Eye in the Sky” was beamed to humanity’s constant eye in the sky — the International Space Station — we just about exploded with space geekiness. It’s even more awesome that the video accompanying the song has tons of space scenes to enjoy.

Turns out the band’s song is Expedition 36 astronaut Luca Parmitano’s favorite, which is why Parsons dedicated that to him during a July 23 Alan Parsons Live Project concert at the Foro Italico in Rome.

Continue reading “Alan Parson’s Project Dedicates Song to ISS Astronaut Parmitano”

Solar Cycle #24: On Track to be the Weakest in 100 Years

Projected vs observed sunspot numbers for solar cycles #23 & #24. (Credit: Hathaway/NASA/MSFC).

Our nearest star has exhibited some schizophrenic behavior thus far for 2013.

By all rights, we should be in the throes of a solar maximum, an 11-year peak where the Sun is at its most active and dappled with sunspots.

Thus far though, Solar Cycle #24 has been off to a sputtering start, and researchers that attended the meeting of the American Astronomical Society’s Solar Physics Division earlier this month are divided as to why.“Not only is this the smallest cycle we’ve seen in the space age, it’s the smallest cycle in 100 years,” NASA/Marshall Space Flight Center research scientist David Hathaway said during a recent press teleconference conducted by the Marshall Space Flight Center.

Cycle #23 gave way to a profound minimum that saw a spotless Sol on 260 out of 365 days (71%!) in 2009. Then, #Cycle 24 got off to a late start, about a full year overdue — we should have seen a solar maximum in 2012, and now that’s on track for the late 2013 to early 2014 time frame. For solar observers, both amateur, professional and automated, it seems as if the Sun exhibits a “split-personality” this year, displaying its active Cycle #24-self one week, only to sink back into a blank despondency the next.

This new cycle has also been asymmetrical as well. One hallmark heralding the start of a new cycle is the appearance of sunspots at higher solar latitudes on the disk of the Sun. These move progressively toward the Sun’s equatorial regions as the cycle progresses, and can be mapped out in what’s known as a Spörer’s Law.

The sunspot number "butterfly" graph, illustrating Spörer's Law that susnpots gradually migrate towards the equator of the Sun as the solar cycle progresses. (Credit: NASA/MSFC).
The sunspot number “butterfly” graph, illustrating Spörer’s Law that susnpots gradually migrate towards the equator of the Sun as the solar cycle progresses. (Credit: NASA/MSFC).

But the northern hemisphere of the Sun has been much more active since 2006, with the southern hemisphere experiencing a lag in activity. “Usually this asymmetry lasts a year or so, and then the hemispheres synchronize,” said Giuliana de Toma of the High Altitude Observatory.

So far, several theories have been put forth as to why our tempestuous star seems to be straying from its usual self. Along with the standard 11-year cycle, it’s thought that there may be a longer, 100 year trend of activity and subsidence known as the Gleissberg Cycle.

The Sun is a giant ball of gas, rotating faster (25 days) at the equator than at the poles, which rotate once every 34.5 days. This dissonance sets up a massive amount of torsion, causing the magnetic field lines to stretch and snap, releasing massive amounts of energy. The Sun also changes polarity with every sunspot cycle, another indication that a new cycle is underway.

But predictions have run the gamut for Cycle #24. Recently, solar scientists have projected a twin peaked solar maximum for later this year, and thus far, Sol seems to be following this modified trend.  Initial predictions by scientists at the start of Cycle #24 was for the sunspot number to have reached 90 by August 2013; but here it is the end of July, and we’re sitting at 68, and it seems that we’ll round out the northern hemisphere Summer at a sunspot number of 70 or so.

Some researchers predict that the following sunspot Cycle #25 may even be absent all together.

“If this trend continues, there will be almost no spots in Cycle 25,” Noted Matthew Penn of the National Solar Observatory, hinting that we may be on the edge of another Maunder Minimum.

Looking back over solar cycles for the past 500 years. (Credit: D. Hathaway/NASA/MSFC).
Looking back over solar cycles for the past 500 years. (Credit: D. Hathaway/NASA/MSFC).

The Maunder Minimum was a period from 1645 to 1715 where almost no sunspots were seen. This span of time corresponded to a medieval period known as the Little Ice Age. During this era, the Thames River in London froze, making Christmas “Frost Fairs” possible on the ice covered river. Several villages in the Swiss Alps were also consumed by encroaching glaciers, and the Viking colony established in Greenland perished. The name for the period comes from Edward Maunder, who first noted the minimum in papers published in the 1890s. The term came into modern vogue after John Eddy published a paper on the subject in the journal of Science in 1976. Keep in mind, the data from the period covered by the Maunder Minimum is far from complete— Galileo had only started sketching sunspots via projection only a few decades prior to the start of the Maunder Minimum. But tellingly, there was a span of time in the early 18th century when many researchers supposed that sunspots were a myth! They were really THAT infrequent…

Just what role a pause in the solar cycle might play in the climate change debate remains to be seen. Perhaps, humanity is getting a brief (and lucky) reprieve, a chance to get serious about controlling our own destiny and doing something about anthropogenic climate-forcing. On a more ominous note, however, an extended cooling phase may give us reason to stall on preparing for the inevitable while giving ammunition to deniers, who like to cite natural trends exclusively.

Down but not out? Sol looking more like its solar max-self earlier this month on July 8th. (Photo by author).
Down but not out? Sol looking more like its solar max-self earlier this month on July 8th. (Photo by author).

Whatever occurs, we now have an unprecedented fleet of solar monitoring spacecraft on hand to watch the solar drama unfold. STEREO A & B afford us a 360 degree view of the Sun. SOHO has now monitored the Sun for the equivalent of more than one solar cycle, and NASA’s Solar Dynamics Observatory has joined it in its scrutiny. NASA’s Interface Region Imaging Spectrograph (IRIS)  just launched earlier this year, and has already begun returning views of the solar atmosphere in unprecedented detail. Even spacecraft such as MESSENGER orbiting Mercury can give us vital data from other vantage points in the solar system.

Cycle #24 may be a lackluster performer, but I’ll bet the Sun has a few surprises in store. You can always get a freak cloud burst, even in the middle of a drought. Plus, we’re headed towards northern hemisphere Fall, a time when aurora activity traditionally picks up.

Be sure to keep a (safely filtered) eye on ol’ Sol— it may be the case over these next few years that “no news is big news!”

 

 

30 Years of City Growth Seen From Space

China's now-industrialized Pearl River Delta, seen in October 1973 (top) and January 2003 (bottom)

Since the launch of its first satellite in 1972, the eight NASA/USGS Landsat satellites have made the longest continuous observations of Earth’s surface, providing invaluable data for research in agriculture, geology, forestry, regional planning, education, mapping, global change research, as well as important emergency response and disaster relief information. In addition, having such a long span of data allows us to easily see the expansion of human development in many areas — unprecedented before-and-after views of city growth seen from space.

These images, taken over the course of the Landsat program, illustrate the visible impact of over three decades of human development:

Chandler, Arizona imaged in 1985 (top) and 2011 (bottom.)  As its economy shifted from agriculture to manufacturing and electronics, Chandler's population multiplied 8 times to over 236,000.
Chandler, Arizona imaged in 1985 (top) and 2011 (bottom.) As its economy shifted from agriculture to manufacturing and electronics, Chandler’s population multiplied 8 times to over 236,000.
The explosion of Istanbul's population from 2 to 3 million people is evident in these Landsat images, comparing 1975 to 2011. Vegetation appears red in the imaging wavelengths used here.
The explosion of Istanbul’s population from 2 to 13 million people is evident in these Landsat images, comparing 1975 to 2011. Vegetation appears red in the imaging wavelengths used here.
A few years ago one of the fastest-growing cities in the US, Las Vegas is seen here in images taken in 1984 (top) and 2011 (bottom.) The sprawling development -- as well as the decrease in water level of Lake Mead -- is evident.
A few years ago one of the fastest-growing cities in the US, Las Vegas is seen here in images taken in 1984 (top) and 2011 (bottom.) The sprawling development — as well as the decrease in water level of Lake Mead — is evident.
Some of the most dramatic -- and rapid --  changes have occurred in Dubai, whose artificial offshore islands suddenly appear between images taken in 2000 (top) and 2010 (bottom.) Once barely visible against the desert landscape, Dubai is now an international center of business, tourism, and oil production.
Some of the most dramatic — and rapid — changes have occurred in Dubai, whose palm- and continent-shaped artificial islands suddenly appear between images taken in 2000 (top) and 2010 (bottom.) Once barely visible against the desert landscape, Dubai is now an international center of business, tourism, and oil production.

See more of these images on NASA Goddard Space Flight Center’s Flickr album here.

The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey. In 1972, the launch of ERTS-1 (Earth Resources Technology Satellite, later renamed Landsat 1) started the era of a series of satellites that have since continuously acquired space-based land remote sensing data.

The latest satellite in the Landsat series, the Landsat Data Continuity Mission (LDCM) — now named Landsat 8 — was launched on February 11, 2013. Landsat 8 data is now available free to the public online here.

Read more on the USGS Landsat mission page here.

Image credits: USGS/NASA

Podcast: Sound in Space

Shhhh, shhh. You can stop screaming. That’s because nobody can hear you … in space. But why not? How does sound work here on Earth, and what would it sound like on other planets?

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Sound” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout (usually recorded every Monday at 3 pm Eastern Time):

Whimsical and Beautiful New Timelapse: Borrego Stardance

A still from the new timelapse, 'Borrego Stardance' by Gavin Heffernan/Sunchaser Pictures.

Just outside of Borrego Springs, California, monsters lurk. Life-size metal statues of dinosaurs, dragons, and wooly mammoths stand among giant insects, birds and several other creatures. But the 600,000 acre Anzo-Borrego State Park is also an astronomer’s dream, since it is one of four communities in the world to be classified a “Dark Sky Community” by the International Dark Sky Association.

Timelapse maven Gavin Heffernan from Sunchaser Pictures has now combined these monsters and the beautiful dark sky for his latest astronomical timelapse video, Borrego Stardance. It’s an unusual and fanciful look at the night sky –- where else can you see dragons and star trails at the same time? Watch below — and crank the volume for added effect!

“Despite the grueling 112 degree temperatures, my team and I had an amazing shoot, with some of the clearest Milky Way footage we’ve ever captured” Gavin wrote Universe Today via email, “as well as some exciting creature-filled star trails, and more experiments with “Starscaping” (switching from stars to trails mid-shot).”

It’s a beautiful addition to Gavin’s already impressive timelapse and video collection. You can see a behind-the-scenes video of the Borrego site here.

You can find more information on the statues at the Galleta Meadows website.

BORREGO STARDANCE from Sunchaser Pictures on Vimeo.

Astronomers See Snow … In Space!

Artist's conception of the snow line in TW Hydrae. Credit: Bill Saxton/Alexandra Angelich, NRAO/AUI/NSF

There’s an excellent chance of frost in this corner of the universe: astronomers have spotted a “snow line” in a baby solar system about 175 light-years away from Earth. The find is cool (literally and figuratively) in itself. More importantly, however, it could give us clues about how our own planet formed billions of years ago.

“[This] is extremely exciting because of what it tells us about the very early period in the history of our own solar system,” stated Chunhua Qi, a researcher with the Harvard-Smithsonian Center for Astrophysics who led the research.

“We can now see previously hidden details about the frozen outer reaches of another solar system, one that has much in common with our own when it was less than 10 million years old,” he added.

The real deal enhanced-color picture of TW Hydrae is below, courtesy of a newly completed telescope: the Atacama Large Millimeter/submillimeter Array in Chile. It is designed to look at grains and other debris around forming solar systems. This snow line is huge, stretching far beyond the equivalent orbit of Neptune in our own solar system. See the circle? That’s Neptune’s orbit. The green stuff is the snow line. Look just how far the green goes past the orbit.

The carbon monoxide line as seen by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The circle represents the equivalent orbit of Neptune when comparing it to our own solar system. Credit: Karin Oberg, Harvard University/University of Virginia
The carbon monoxide line on TW Hydrae as seen by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The circle represents the equivalent orbit of Neptune when comparing it to our own solar system. Credit: Karin Oberg, Harvard University/University of Virginia

Young stars are typically surrounded by a cloud of gas and debris that, astronomers believe, can in many cases form into planets given enough time. Snow lines form in young solar systems in areas where the heat of the star isn’t enough to melt the substance. Water is the first substance to freeze around dust grains, followed by carbon dioxide, methane and carbon monoxide.

It’s hard to spot them: “Snow lines form exclusively in the relatively narrow central plane of a protoplanetary disk. Above and below this region, stellar radiation keeps the gases warm, preventing them from forming ice,” the astronomers stated. In areas where dust and gas are more dense, the substances are insulated and can freeze — but it’s difficult to see the snow through the gas.

In this case, astronomers were able to spot the carbon monoxide snow because they looked for diazenylium, a molecule that is broken up in areas of carbon monoxide gas. Spotting it is a “proxy” for spots where the CO froze out, the astronomers said.

Here are some more of the many reasons this is exciting to astronomers:

  • Snow could help dust grains form faster into rocks and eventually, planets because it coats the grain surface into something more stickable;
  • Carbon monoxide is a requirement to create methanol, considered a building block of complex molecules and life;
  • The snow was actually spotted with only a small portion of ALMA’s 66 antennas while it was still under construction. Now that ALMA is complete, scientists are already eager to see what the telescope will turn up the next time it gazes at the system.

Source: National Radio Astronomy Observatory

 

Carnival of Space #312

This week’s Carnival of Space is hosted by Stefan Lamoureux at his Links Through Space blog.

Click here to read Carnival of Space #312.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

Zogg From Betelgeuse Explains Why the Universe Has No Edge

Trying to explain the topology of the Universe is really complicated… for humans. But it clearly comes naturally to Zogg the Alien from Betelgeuse. In this 10-minute video, the plucky alien vividly describes how we could have a Universe which is flat and finite, but doesn’t have an edge. How we could travel in one direction and return to our starting point, never bumping into the outside of the Universe.

What is the Universe expanding into? Nothing, it’s just expanding.

Dig a little further through Zogg’s YouTube channel, and you’ll see a great collection of explainers on eating, vision; and even esoteric topics like imagination and beauty.

I’d love to see more in this series Zogg… hint, hint.