This false-color composite image, taken with the Hubble Space Telescope, reveals the orbital motion of the planet Fomalhaut b. Credit: NASA, ESA, and P. Kalas (University of California, Berkeley and SETI Institute)
Fomalhaut is a really cool place to study. The naked-eye star (the brightest star in the constellation Piscis Austrinus) has a planet, Fomalhaut b, that once appeared dead but rose again in science circles. It is the site of a comet massacre. Now it’s getting even more interesting: Scientists have believed for years that Fomalhaut is a double star, but a new paper proposes that it is actually a triplet.
“I noticed this third star a couple of years ago when I was plotting the motions of stars in the vicinity of Fomalhaut for another study,” stated Eric Mamajek, associate professor of physics and astronomy at the University of Rochester. The third star is known as LP876-10 or Fomalhaut C.
“However, I needed to collect more data and gather a team of co-authors with different observations to test whether the star’s properties are consistent with being a third member of the Fomalhaut system.”
That opportunity came when Mamajek was in Chile and by chance, talking with Georgia State University’s Todd Henry, who is the director of the Research Consortium on Nearby Stars. A student (who has now graduated), Jennifer Bartlett at the University of Virginia, was working on a study of potential nearby stars for her Ph.D. thesis, which included the star that Mamajek was curious about.
Herschel’s far-infrared observations of Fomalhaut and its disk. Credit: ESA
The team plotted the star’s movements and spectroscopy (to see its temperature and radial velocity) and concluded the speed and distance of the star matched that of the Fomalhaut system.
LP876-10/Fomalhaut C is a red dwarf that appears the distance of 11 full moons apart from Fomalhaut in the night sky. It seems counterintuitive to believe they are close together, but the team reminds us that Fomalhaut is very close to us as stars go: 25 light-years away.
“That they appear so far apart could explain why the connection between LP 876-10 and Fomalhaut had been previously missed,” the team stated.
Technicians resumed spacecraft preparations for NASA’s MAVEN orbiter today (Oct. 3) towards meeting the hoped for Nov. 18 launch to Mars after receiving an ‘emergency exemption’ from forced furloughs. The Oct. 1 US Government shutdown had stopped all work on MAVEN and other NASA missions. Credit: Ken Kremer/kenkremer.com
Technicians resumed spacecraft preparations for NASA’s MAVEN orbiter today (Oct. 3) aimed towards meeting the hoped for Nov. 18 launch to Mars after receiving an ‘emergency exemption’ from forced furloughs. The Oct. 1 US Government shutdown had stopped all work on MAVEN and various other NASA missions. Credit: Ken Kremer/kenkremer.com Story updated[/caption]
Following a three day period of complete work stoppage due to the US Government Shutdown, technicians late today (Oct. 3) resumed critical launch preparations for NASA’s next mission to Mars, the MAVEN orbiter. And it’s not a moment too soon, because the consequences of a continued suspension would have been absolutely dire for the entire future of Mars exploration!
“We have already restarted spacecraft processing at the Kennedy Space Center (KSC) today,” Prof. Bruce Jakosky, MAVEN’s chief scientist told Universe Today in a special new mission update today.
Today, Oct 3, top NASA managers have “determined that MAVEN meets the requirements allowing an emergency exception relative to the Anti-Deficiency Act,” Jakosky told me.
MAVEN had been scheduled to blast off for the Red Planet on Nov.18 atop an Atlas V rocket from the Florida Space Coast until those plans were derailed by the start of the government shutdown that began at midnight, Tuesday (Oct. 1) due to senseless and endless political gridlock in Washington, DC.
The upcoming Nov. 18 blastoff of NASA’s new MAVEN Mars orbiter was threatened by the US Federal Government shutdown when all launch processing work ceased on Oct. 1. Spacecraft preps had now resumed on Oct. 3. MAVEN was unveiled to the media, including Universe Today, inside the cleanroom at the Kennedy Space Center on Sept. 27, 2013. With solar panels unfurled, this is exactly how MAVEN looks when flying through space. Credit: Ken Kremer/kenkremer.com
About 97% of NASA’s workforce had been immediately furloughed on Oct. 1 and ordered not to go to work – along with some 800,000 other Federal employees – when their work was deemed “non-essential” despite maintaining spacecraft valued at tens of billions of dollars.
This left only skeleton crews manning Mission Control’s for dozens and dozens of ongoing space missions and the International Space Station (ISS)
Despite the work hiatus, the team is still hoping to achieve an on time launch or soon thereafter.
“We are working toward being ready to launch on Nov. 18,” Jakosky told me, as MAVEN’s principal Investigator of the University of Colorado at Boulder.
“We will continue to work over the next couple of days to identify any changes in our schedule or plans that are necessary to stay on track.”
How realistic is the original Nov. 18 launch date, I asked?
“We think it’s very feasible,” Jakosky responded.
“With our having been shut down for only a few days, we should be back on track toward this date quickly.”
The processing team at KSC lost three days of the nine days of margin in the schedule.
The upcoming Nov. 18 blastoff of NASA’s new MAVEN Mars orbiter was threatened by the US Federal Government shutdown when all launch processing work ceased on Oct. 1. Spacecraft preps had now resumed on Oct. 3 after receiving an emergency exemption. MAVEN was unveiled to the media, including Universe Today, inside the cleanroom at the Kennedy Space Center on Sept. 27, 2013. With solar panels unfurled, this is exactly how MAVEN looks when flying through space. Credit: Ken Kremer/kenkremer.com
Where does the team pick up with work?
“With the facility now back up and running, we more or less pick up right where we left off,” Jakosky explained
“We are reworking the schedule to make sure our activities are integrated together and that people don’t have to be in two places at once.”
Magnetometer science instrument boom juts out from MAVEN solar panel during launch processing inside the clean room at the Kennedy Space Center. Credit: Ken Kremer/kenkremer.com
The nominal launch window for NASA’s $650 Million MAVEN (Mars Atmosphere and Volatile EvolutioN Mission) mission to study the Red Planet’s atmosphere only extends about three weeks until Dec. 7.
And he said the team will do whatever necessary, including overtime, to launch MAVEN to the Red Planet by Dec. 7.
“The team is committed to getting to the launch pad at this opportunity, and is willing to work double shifts and seven days a week if necessary. That plus the existing margin gives us some flexibility. “
Interestingly, the ‘’emergency exemption” was granted because of MAVEN’s additional secondary role as a communications relay for NASA’s intrepid pair of surface rovers – Curiosity and Opportunity – and not because of its primary science mission.
“MAVEN is required as a communications relay in order to be assured of continued communications with the Curiosity and Opportunity rovers,” Jakosky explained.
NASA’s MAVEN Mars orbiter, chief scientist Prof. Bruce Jakosky of CU-Boulder and Ken Kremer of Universe Today inside the clean room at the Kennedy Space Center on Sept. 27, 2013. MAVEN launches to Mars on Nov. 18, 2013 from Florida. Credit: Ken Kremer/kenkremer.com
Although NASA has two functioning orbiters circling the Red Planet at this moment, they are getting old, are far beyond their original design lifetimes and suffer occasional glitches. And there is no guarantee of continued operation.
“The rovers are presently supported by Mars Odyssey launched in 2001 and Mars Reconnaissance Orbiter launched in 2005.”
“Launching MAVEN in 2013 protects the existing assets that are at Mars today,” Jakosky told me.
If Mars Odyssey and/or Mars Reconnaissance Orbiter were to fail, then the rovers mission operations would be severely curtailed and could even be terminated prematurely – in a worst case scenario.
And without MAVEN, there would be no point in launching NASA’s planned 2020 rover since there would be no way to transmit the science data back to Earth.
“There is no NASA relay orbiter at Mars planned post-MAVEN,” Jakosky noted.
If MAVEN has to launch later in December 2013 or is forced to be postponed to the next launch window opportunity in 2016, both the communications relay capability and the missions atmospheric science objectives would have been very badly impacted.
“A delay in the launch date by more than a week past the end of the nominal launch period, or a delay of launch to 2016, would require additional fuel to get into orbit.”
“This would have precluded having sufficient fuel for MAVEN to carry out its science mission and to operate as a relay for any significant time,” Jakosky elaborated.
“Our nominal launch period runs from 18 November through 7 December, and we can launch as late as about 15 December without a significant impact on our combined science and relay activities.”
From a purely science standpoint, 2013 is the best time to launch MAVEN to accomplish its science objectives.
“Although the exception for MAVEN is not being done for science reasons, the science of MAVEN clearly will benefit from this action.”
“Launching in 2013 allows us to observe at a good time in the eleven-year solar cycle.”
“MAVENS’s goal is determining the composition of the ancient Martian atmosphere and when it was lost, where did all the water go and how and when was it lost,” said Jakosky.
Stay tuned here for continuing MAVEN and government shutdown updates.
And watch for my articles about critical operations related to LADEE on Oct 6 and JUNO on Oct. 9. The government shutdown negatively impacts these missions and others as well.
Students in a school in Tanzania view the Sun with Astronomers Without Borders filter glasses. Credit: Astronomers Without Borders.
Astronomers Without Borders – those great folks who do science outreach around the world – is getting ready for the next solar eclipse, which takes place on November 3, 2013. A partial eclipse will be visible across a wide swath of Africa and AWB needs your help so that tens of thousands of eclipse glasses can be sent to schools in Africa in time for the eclipse.
“We’re working with the IAU’s Office of Astronomy for Development who has contacts working with schools and able to distribute the glasses to them,” Mike Simmons, who leads AWB, told Universe Today via email. “The opportunity for this came up late so we’re working very hard to make it happen in the short time we have left.”
Simmons added that this is a rare opportunity to expose students to science in a region where science resources are often non-existent, and AWB will be giving the glasses to schools at no charge.
Animation of 2013 November 3 solar eclipse. The large gray circle shows the area of the partial solar eclipse. The very small dark dot in the middle depicts the path of the total solar eclipse. Credit: NASA/Goddard Space Flight Center.
The AWB website says that schools have been identified and vetted by partner organizations in each country in Africa, and distribution networks have been verified. Every donated pair of eclipse glasses WILL reach a student for use for the eclipse. The International Astronomical Union’s Office of Astronomy for Development, which is based in Cape Town, South Africa, is providing invaluable support and assistance through their many contacts across Africa.
This program depends entirely on donations.
“There’s no question we can get all the donations that are needed as long as we get the word out in time,” Simmons said.
Please consider donating, as AWB does amazing work.
“We do probably a half-million dollars in programs each year based on the hard work of passionate amateur astronomers and educators around the world,” Simmons said, “all on way less than $25,000 a year.”
This is a great astronomy outreach organization that really could use financial help of any kind, so feel free to donate to their general cause, as well.
You can also purchase eclipse glasses for your own use from AWB here.
Everyone knows that the Moon goes through phases, but let’s talk about why it does. It comes down to illumination, which in this case, all originates from our nearby star.
Our Moon orbits around our planet, and this Earth-Moon system orbits around the Sun.
Even though we only see light on part of the Moon, from the perspective of the Sun, half of it is always illuminated.
Stuck here on Earth, we see the Moon in various phases of illumination as it completes a 27.3 day orbit around the Earth.
As The Moon travels around us we see it pass through its phases. It goes from New Moon, to Full Moon and back to new Moon again.
Crescent Moons are when it’s less than half illuminated, and gibbous when it’s more than half.
“Waxing” means that the Moon becomes more illuminated night-by-night, and the term “waning” means that it’s getting less illuminated each night.
New Moon – When the illuminated side of the Moon is away from the Earth. The Moon and the Sun are lined up on the same side of the Earth, so we can only see the shadowed side. This is also the time that you can experience solar eclipses, when the Moon passes directly in front of the Sun and casts a shadow onto the surface of the Earth. During a new moon, we can also see the reflected light from the Earth, since no sunlight is falling on the Moon – this is known as earthshine.
Crescent – The crescent moon is the first sliver of the Moon that we can see. From the northern hemisphere, the crescent moon has the illuminated edge of the Moon on the right. This situation is reversed for the southern hemisphere.
First Quarter – Although it’s called a quarter moon, we actually see this phase when the Moon is half illuminated. This means that the Sun and the Moon make a 90-degree angle compared to the Earth.
Waxing Gibbous – This phase of the Moon occurs when the Moon is more illuminated that half, but it’s not yet a full Moon.
Full Moon – This is the phase when the Moon is brightest in the sky. From our perspective here on Earth, the Moon is fully illuminated by the light of the Sun. This is also the time of the lunar month when you can see lunar eclipses – these occur when the Moon passes through the shadow of the Earth.
Waning Gibbous – In this lunar phase, the Moon is less than fully illuminated, but more than half.
Last Quarter – At this point of the lunar cycle, the Moon has reached half illumination. Now it’s the left-hand side of the Moon that’s illuminated, and the right-hand side in darkness (from a northern hemisphere perspective).
Crescent – This is the final sliver of illuminated moon we can see before the Moon goes into darkness again.
If you ever get the chance to travel to the other hemisphere, you’ll immediately notice how unfamiliar the Moon behaves – it’s upside down.
If you live in the Northern Hemisphere, after a New Moon the crescent begins on the right-side. But if you’re in the Southern Hemisphere, it’s reversed, with the illumination starting on the left side.
Weird.
The alignment of the Sun, Earth and Moon can lead to some fantastic astronomical events.
When the Moon is new, it can pass in between the Earth and the Sun, casting its shadow down on our planet. As you know, a solar eclipse.
Solar Eclipse as seen by Hinode SatelliteYou’d think we would see a solar and lunar eclipse every month, but we don’t because the Moon’s orbit is inclined relative to the Sun.
Most months, the Moon is either above or below the Sun in the sky, so they just don’t line up perfectly.
Phases of Venus. Image credit: ESOOne more thing, you might not know that Venus also goes through phases. When the planet is on the other side of the Sun from us, we see it as a nearly complete disk. But when Venus is on our side, just about to pass into the glow of the Sun, it’s a thin crescent, just like how we see the Moon.
I hope this gives you a better understanding of why the Moon goes through its phases every month, and the interesting relationship between the Earth, the Sun, and the Moon.
Image of a galaxy with rendering showing a stream of inflowing gas, as rendered in a supercomputer. Credit: MPIA (G. Stinson / A.V. Maccio)
“Primordial hydrogen” sounds like a great name for a band. It’s also a great thing to find when you’re looking at a galaxy. This ancient gas is a leftover of the Big Bang, and astronomers discovered it in a faraway star-forming galaxy that was created when the universe was young.
A continuous stream of gas was likely responsible for a cornucopia of star formation that took place about 10 billion years ago, when galaxies were churning out starbirths at a furious rate.
The astronomers spotted the gas by using a quasar that lit up the fuel from behind. Quasars a handy tool to use if you want to illuminate something, because even though quasars don’t live for very long in cosmic terms — they occur when matter falls into a ginormous black hole — they are extremely bright. Since the gas absorbs the light at certain frequencies, the absorption lines that show up in spectrometers reveal information about the composition, temperature and density of the gas.
“This is not the first time astronomers have found a galaxy with nearby gas, revealed by a quasar. But it is the first time that everything fits together,” stated Neil Crighton, who is with the Max Planck Institute for Astronomy and Swinburne University and led the research. His team found the galaxy using the Keck I telescope in Hawaii.
“The galaxy is vigorously forming stars,” added Crighton, “and the gas properties clearly show that this is pristine material, left over from the early universe shortly after the Big Bang.”
Q1442-MD50 (as the galaxy is called) is 11 billion light years away from us — pretty close to the start of the universe about 13.8 billion years ago. The quasar that lit it up is called QSO J1444535+291905.
“Since this discovery is the result of a systematic search, we can now deduce that such cold flows are quite common,” stated Joseph Hennawi, the leader of the ENIGMA research group at the Max Planck Institute for Astronomy. “We only had to search 12 quasar-galaxy pairs to discover this example. This rate is in rough agreement with the predictions of supercomputer simulations, which provides a vote of confidence for our current theories of how galaxies formed.”
You can read more details in the article (which is in Astrophysical Letters) or in this preprint version on Arxiv.
Clay Anderson's shadow during a spacewalk he took in July 2007, while he was part of Expedition 15. Credit: NASA
“Talk about a selfie!” wrote former astronaut Clay Anderson on Twitter yesterday (Oct. 1). He posted that comment along with a favorite photo from Expedition 15, when he was standing in restraints on the robotic Canadarm2. Off in the distance, he saw his shadow against the solar array panels of a Soyuz spacecraft.
That got us thinking — what are the best astronaut selfies? Below are some of our favourites (some intentional, some not) from over the years. Any that we have missed? Let us know in the comments!
JAXA astronaut Aki Hoshide takes a self-portrait during Expedition 32 in September 2012. “Visible in this outworldly assemblage is the Sun, the Earth, two portions of a robotic arm, an astronaut’s spacesuit, the deep darkness of space, and the unusual camera taking the picture,” NASA wrote. Credit: NASA
Apollo 12’s Pete Conrad is visible in the helmet of crewmate Al Bean during their moon landing in November 1969. Credit: NASAExpedition 15 crewmember and NASA astronaut Clay Anderson nabbed this self-portrait during a spacewalk in August 2007. Credit: NASASelf-portrait of Expedition 36/37 European Space Agency astronaut Luca Parmitano during a July 2013 spacewalk. Credit: NASAAl Shepard raises the American flag during Apollo 14 in February 1971. Below is the shadow of his crewmate, Ed Mitchell. Credit: NASANASA astronaut Mike Fossum grabbed this self-portrait in July 2011, with space shuttle Atlantis visible in the background. Credit: NASANASA astronaut Joe Tanner grabs a helmet shot during a spacewalk on STS-115 in September 2006. Credit: NASAGemini 12 astronaut Buzz Aldrin snaps a picture of himself during a spacewalk in November 1966. Credit: NASAMike Fossum, a mission specialist on STS-121, took this shot in July 2006. In the visor you can see space shuttle Discovery, part of the International Space Station and fellow crewmate Piers J. Sellers. Credit: NASANASA astronaut Scott Parazynski takes a self-portrait during STS-120, which ran from October to November 2007. Credit: NASAGemini 10 astronaut Mike Collins in July 1966. Credit: NASA/Arizona State UniversityExpedition 6’s Don Pettit takes a portrait in January 2003. Also visible in the picture (upper right) is his crewmate, Ken Bowersox. Credit: NASAA teensy-tiny Neil Armstrong is visible in the helmet of Buzz Aldrin during the Apollo 11 landing in July 1969. Credit: NASA
No, this isn’t The Onion… as a concerned consumer of all that is space news, you have indeed arrived at the cyber-doorstep of Universe Today.
I’ll admit though, that we did do a double take about a week back when a peculiar claim came our way via the Iranian Space Agency. Yes, there is an Iranian Space Agency, and it’s kind of frightening that they remain open for business while NASA is largely shutdown.
In mid-September, senior Iranian space program official Mohammad Ebrahimi issued a statement that Iran will attempt another bio-capsule launch “within 45 days”. The unwilling occupant: a Persian cat.
Apparently, a rabbit, a mouse, and another “Space Monkey” were also in the running. Iran’s space program is shrouded in secrecy, and most launches are only announced after they’ve been conducted. This is a convenient political strategy for hiding launch failures that harkens back to the early days of the Cold War. You’re right in guessing that the Iranian Space Agency probably won’t hold a Tweetup for this one. Many western analysts see the Iran’s space effort as a thinly veiled attempt to develop its long range ballistic missile technology. Along with Israel, Iran remains the only Middle Eastern country with the proven technology to conduct indigenous satellite launches.
Iran has stated that it hopes to put an astronaut in orbit by 2019. The Pishgam (or “Pioneer” in Farsi) 2 bio-capsule launch could occur from a mobile launcher at Semnan Space Center as early as October 15th. Satellite sleuths are also expecting activity at Semnan to pick up this month, with the possible launch of SharifSat atop a Safir 1-B rocket, and Iran’s Toulou satellite aboard a rumored new launch vehicle.
Iran successfully became a space-faring nation with the launch of its 27 kilogram Omid satellite on February 2nd, 2009. It isn’t immediately clear if the upcoming launch will be an orbital launch or a sub-orbital ballistic shot. If Pisgam-2 achieves orbit, said “Space Cat” would become the first feline to circle the Earth. If recovery is attempted —again, Iran is always nebulous as to their intentions— it would also be the first time they’ve achieved a return from orbit.
But is “Space Cat” even a reality?
Iran has been caught red-handed before playing a shell game with the media in terms of its space program. Earlier this year, “Monkey-gate” erupted, as before-and-after images from the Pisgam-1 bio-capsule suborbital launch clearly showed two different monkeys before and after the flight:
Monkey business? Iran displayed a decidedly different looking monkey before, during, and after launch earlier this year! (Credit: Iran News Agency).
Clearly, Iran and other ‘Axis of Evil’ countries definitely need to sharpen their Photoshop, or at least their monkey-switching skills. Either said monkey launch never actually occurred, or (more likely), the unwilling Iranian space primate never survived the flight.
Perhaps this is why Iran decided on a feline occupant this time around, for possible ease of replacement?
PETA, the People for the Ethical Treatment of Animals, have also issued a statement concerning the impending launch of “Space Cat” by Iran, calling the action an “archaic experiment, a throwback to the primitive techniques of the 1950’s.”
NASA did entertain the idea of “Catronauts” early in the space program. (Credit: NASA).
The U.S. and the Soviet Union launched animals into space as a prelude to human spaceflight. On November 3rd, 1957, Laika the dog became the first animal to orbit the Earth. Laika perished is space due to overheating, as did several unfortunate monkeys that were launched on the first US ballistic tests.
Russia still conducts the occasional launch of animals into space, including the Bion-1M “Space Zoo” mission earlier this year. The Bion missions allow for scientists to dissect the specimens afterwards to study the effects of a month in zero-g, something you can’t do with humans.
And the U.S. did once fly cats in zero-g aboard its Convair C-131 “Vomit Comet” aircraft, as can be seen in this bizarre video:
But the first cat in space was actually launched by France atop a Veronique AGI sub-orbital rocket 50 years ago this month on October 18th, 1963. It would be ironic if Iran conducted it launch this month on the anniversary! The story goes the Felix, the original cat slated for the flight, escaped just prior to launch from the Sahara desert Hammaguir test site in Algeria, and was replaced by the “backup crew,” a female cat named Felicette. Felicette survived the 15 minute flight, reaching an apogee of 217 kilometres. A follow-up launch of a second cat six days later wasn’t so lucky.
Felicette (left) and Felix in publicity shots prior to launch. Note the cranial electrode (!) implants. (Credit: Marjorie-art Voila.net)
As always, Iran’s intentions for the future of its space program remain hidden. Their current launch capabilities remain limited, and are a far cry from being able to hoist a human into orbit anytime soon. If the launch of “Space Cat” does come to pass this month, it’ll be over protests from animal rights groups and the general public. Hey, didn’t the former Iranian president Mahmoud Ahmadinejad say earlier this year after “Monkey-Gate” that he was willing to be “The first Iranian to be sacrificed by the scientists of my country and go into space” as the first Iranian astronaut? Is he really going to let Space Cat upstage him?
Felix and Felicette where also commemorated on several African postage stamps. (Credit: Majorie-art.voila.net).
–Read a great synopsis of the history of felines in space from Heather Archulletta @Pillownaut.
Images of aurora in Alaska captured by two digital SLRs. Differences in the left and right pictures allow researchers to measure at what altitude the electrons were. Credit: Kataoka et al., 2013
Ever stood outside looking at the aurora and felt as though it was swirling just a short distance above your head? It’s hard to judge altitude when looking at sky phenomena because there are few landmarks above us. (The moon effect at the horizon is an example.) But it turns out there is a way to measure aurora altitude.
The eerie, green glow of the Northern Lights swirls about in the video you see above. A group of researchers used a unique but simple technique to measure how high the electrons were during the dazzling light display: they mounted two digital SLRs eight kilometers (five miles) apart in Alaska, and used that old astronomical friend, parallax, to measure distances.
“Using the parallax of the left-eye and the right-eye images, we can calculate the distance to the aurora using a [triangulation] method that is similar to the way the human brain comprehends the distance to an object,” stated Ryuho Kataoka, an associate professor at the National Institute of Polar Research in Japan. “Parallax is the difference in the apparent position of an object when observed at different angles.”
Altitude measurements have been done before using this technique, but it’s the first time digital SLRs were employed, the research team said. A typical aurora has electrons that are between 90 kilometers and 400 kilometers (55 miles and 249 miles) high.
By the way, for all the amateur astronomy photographers, there’s a potential chance for you to get involved with future research activities.
“Commercially available GPS units for digital SLR cameras have become popular and relatively inexpensive, and it is easy and very useful for photographers to record the accurate time and position in photographic files,” said Kataoka. “I am thinking of developing a website with a submission system to collect many interesting photographs from night-sky photographers over the world via the Internet.”
From the Cat’s Eye to the Eskimo, planetary nebulae are arguably among the most dazzling objects in the Universe. These misnamed stellar remnants are created when the outer layers of a dying star blows off and expands into space. However, they can look radically different from one another, revealing complicated histories and structures.
But recently, astronomers have argued that some of the most exotic shapes are the result of not one, but two stars at the center. It is the interaction between the progenitor star and a binary companion that shapes the resulting planetary nebula.
The archetypal planetary nebula is spherical. Most planetary nebulae, however, have been shown to be non-spherical, complex structures.
“LoTr 1 is one such planetary nebula, but with a twist,” Amy Tyndall – a graduate student at the University of Manchester and lead author on the study – told Universe Today. It has not one star at its center but two. The binary central star system consists of a faint, hot white dwarf and a cool companion – a rapidly rotating giant.
LoTr 1 with a binary central star system and two slightly elongated shells, with ages of 17 and 35 thousand years. Credit: Tyndal et al.
LoTr 1 was first discovered by astronomers using the 1.2 meter telescope at the Royal Observatory in Edinburgh, Scotland. At the time it seemed that LoTr 1 was similar to a particular group of 4 planetary nebulae (Abell 35, Abell 70, WeBo 1 and LoTr 5), all of which had a central binary star system.
Another common factor amongst this particular group is that in most cases the companion star seemed to be a barium star – a cool giant that shows relatively large amounts of barium. Before the planetary nebula forms, the progenitor star dredges up an excess amount of Barium on its surface. It then releases a Barium-enriched stellar wind, which falls on its companion star.
“After the stellar envelope is ejected to form the surrounding nebula, the giant star evolves into a white dwarf, while the contaminated star retains the barium from the wind as it continues to evolve to form a Barium star,” explains Tyndall.
Tyndall and her collaborates set out to see if the companion star within LoTr 1 was in fact a Barium star. They acquired data from telescopes in both Chile and Australia and compared their results to the two other elusive planetary nebulae in the group: Abell 70 and WeBo 1.
“If barium is indeed present, it would be a good step further towards our understanding of how mass is transferred between stars in a binary system, and how that subsequently affects the formation and morphology of planetary nebulae,” says Tyndall.
While the results show that LoTr 1 does consist of binary star system, the companion star is not a Barium star. But a null result is still a result. “LoTr 1 remains an interesting object to us as it shows that we still have huge gaps in our knowledge as to how these stunning objects form,” Tyndall told Universe Today.
Without the presence of Barium, it would appear at first that little mass was transferred to the companion star. However, the companion star is rotating rapidly, which is a direct consequence of mass transfer. The most plausible explanation is that the mass was transferred before the barium could be dredged up to the stellar surface.
If the stellar evolution was cut short this way then there will be detectable evidence in the properties of the white dwarf. The next step will be to take another look at this odd planetary nebula in hopes of better understanding the complexities of this system.
The paper has been accepted for publication in the Monthly Notices of the Royal Astronomical Society and is available for download here.
Oxus Patera, a candidate supervolcano on Mars. The image was created by putting color pictures from Mars Express' High Resolution Stereo Camera on top of digital elevation data it collected. Credit: ESA/Mars Express/Freie Universitat Berlin/Google
Once-active “supervolcanoes” in northern Mars likely spewed ash and dust thousands of miles away, producing powdery deposits noticed by the NASA’s Curiosity and Opportunity rovers closer to the equator, a new study suggests.
The scientists suspect that irregularly shaped craters in Arabia Terra, which is in the northern highlands of Mars, are leftovers of huge volcanoes from eons ago. Until now, those areas weren’t pegged as volcanoes at all.
“Discovering supervolcanic structures fundamentally changes how we view ancient volcanism on Mars,” stated Joseph Michalski, a Mars researcher at the Natural History Museum in London and the Planetary Institute in Tucson, Arizona.
“Many Martian volcanoes are easily recognized from their massive shield-shaped structure, similar to what we see in Hawaii. But these are relatively youthful features on Mars, and we have always wondered where the ancient volcanoes are. It is possible that the most ancient volcanoes were much more explosive and formed structures similar to what we now see in Arabia Terra.”
As some scientists believe that the crust of Mars was thinner than it is now, this would let magma erupt to the surface before it could release gases inside the crust, the team added. The finding also has implications for predicting the ancient atmosphere and looking at habitability.
“If future work shows that supervolcanoes were present more widely on ancient Mars, it would completely change estimates of how the atmosphere formed from volcanic gases, how sediments formed from volcanic ash and how
habitable the surface might have been,” Michalski added.
Be sure to check out the full paper in Nature. Author affiliations include the Planetary Science Institute in Arizona, the London Natural History Museum, and the NASA Goddard Space Flight Center.
