The four new, but as yet unconfirmed, exoplanets. Image: University of British Columbia
A student at the University of British Columbia (UBC), Canada, has discovered four new exoplanets hidden in data from the Kepler spacecraft.
Michelle Kunimoto recently graduated from UBC with a Bachelor’s degree in physics and astronomy. As part of her coursework, she spent a few months looking closely at Kepler data, trying to find planets that others had overlooked.
In the end, she discovered four planets, (or planet candidates until they are independently confirmed.) The first planet is the size of Mercury, two are roughly Earth-sized, and one is slightly larger than Neptune. According to Kunimoto, the largest of the four, called KOI (Kepler Object of Interest) 408.05, is the most interesting. That one is 3,200 light years away from Earth and occupies the habitable zone of its star.
“Like our own Neptune, it’s unlikely to have a rocky surface or oceans,” said Kunimoto, who graduates today from UBC. “The exciting part is that like the large planets in our solar system, it could have large moons and these moons could have liquid water oceans.”
Her astronomy professor, Jaymie Matthews, shares her enthusiasm. “Pandora in the movie Avatar was not a planet, but a moon of a giant planet,” he said. And we all know what lived there.
On its initial mission, Kepler looked at 150,000 stars in the Milky Way. Kepler looks for dips in the brightness of these stars, which can be caused by planets passing between us and the star. These dips are called light curves, and they can tell us quite a bit about an exoplanet.
“A star is just a pinpoint of light so I’m looking for subtle dips in a star’s brightness every time a planet passes in front of it,” said Kunimoto. “These dips are known as transits, and they’re the only way we can know the diameter of a planet outside the solar system.”
Michelle Kunimoto and her prof., Jaymie Matthews, at the University of British Columbia in Vancouver, Canada. Image: Martin Dee/UBC
One of the limitations of the Kepler mission is that it’s biased against planets that take a long time to orbit their star. That’s because the longer the orbit is, the fewer transits can be witnessed in a given amount of time. The “warm Neptune” KOI 408.05 found by Kunimoto takes 637 days to orbit its sun.
This long orbit explains why the planet was not found initially, and also why Kunimoto is receiving recognition for her discovery. It took a substantial commitment and effort to uncover it. Kepler has discovered almost 5,000 planet and planet candidates, and of those, only 20 have longer orbits than KOI 408.05.
Kunimoto and Matthews have submitted the findings to the Astronomical Journal. They may be the first of many submissions for Kunimoto, as she is returning to UBC next year to earn a Master’s Degree in physics and astronomy, when she will hunt for more planets and investigate their habitability.
The fun didn’t end with her exoplanet discovery, however. As a Star Trek fan (who isn’t one?) she was lucky enough to meet William Shatner at an event at the University, and to share her discovery with Captain James Tiberius Kirk.
It makes you wonder what other surprises might lie hidden in the Kepler data, and what else might be uncovered. Might a life-bearing planet or moon, maybe the only one, be found in Kepler’s data at some future time?
This image shows the galaxy PKS B1424-418, and the blazar that lives there. The dotted circle is the area in which Fermi detected the neutrino Big Bird. Image: NASA/DOE/LAT Collaboration.
A unique observatory buried deep in the clear ice of the South Pole region, an orbiting observatory that monitors gamma rays, a powerful outburst from a black hole 10 billion light years away, and a super-energetic neutrino named Big Bird. These are the cast of characters that populate a paper published in Nature Physics, on Monday April 18th.
The observatory that resides deep in the cold dark of the Antarctic ice has one job: to detect neutrinos. Neutrinos are strange, standoffish particles, sometimes called ‘ghost particles’ because they’re so difficult to detect. They’re like the noble gases of the particle world. Though neutrinos vastly outnumber all other atoms in our Universe, they rarely interact with other particles, and they have no electrical charge. This allows them to pass through normal matter almost unimpeded. To even detect them, you need a dark, undisturbed place, isolated from cosmic rays and background radiation.
This explains why they built an observatory in solid ice. This observatory, called the IceCube Neutrino Observatory, is the ideal place to detect neutrinos. On the rare occasion when a neutrino does interact with the ice surrounding the observatory, a charged particle is created. This particle can be either an electron, muon, or tau. If these charged particles are of sufficiently high energy, then the strings of detectors that make up IceCube can detect it. Once this data is analyzed, the source of the neutrinos can be known.
The next actor in this scenario is NASA’s Fermi Gamma-Ray Space Telescope. Fermi was launched in 2008, with a specific job in mind. Its job is to look at some of the exceptional phenomena in our Universe that generate extraordinarily large amounts of energy, like super-massive black holes, exploding stars, jets of hot gas moving at relativistic speeds, and merging neutron stars. These things generate enormous amounts of gamma-ray energy, the part of the electromagnetic spectrum that Fermi looks at exclusively.
Next comes PKS B1424-418, a distant galaxy with a black hole at its center. About 10 billion years ago, this black hole produced a powerful outburst of energy, called a blazar because it’s pointed at Earth. The light from this outburst started arriving at Earth in 2012. For a year, the blazar in PKS B1424-418 shone 15-30 times brighter in the gamma spectrum than it did before the burst.
Detecting neutrinos is a rare occurrence. So far, IceCube has detected about a hundred of them. For some reason, the most energetic of these neutrinos are named after characters on the popular children’s show called Sesame Street. In December 2012, IceCube detected an exceptionally energetic neutrino, and named it Big Bird. Big Bird had an energy level greater than 2 quadrillion electron volts. That’s an enormous amount of energy shoved into a particle that is thought to have less than one millionth the mass of an electron.
The IceCube Neutrino Observatory is a series of strings of detectors, drilled deep into the Antarctic ice. Image: Nasa-verve – IceCube Science Team – Francis Halzen, Department of Physics, University of Wisconsin, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=26350372
Big Bird was clearly a big deal, and scientists wanted to know its source. IceCube was able to narrow the source down, but not pinpoint it. Its source was determined to be a 32 degree wide patch of the southern sky. Though helpful, that patch is still the size of 64 full Moons. Still, it was intriguing, because in that patch of sky was PKS B1424-418, the source of the blazar energy detected by Fermi. However, there are also other blazars in that section of the sky.
The scientists looking for Big Bird’s source needed more data. They got it from TANAMI, an observing program that used the combined power of several networked terrestrial telescopes to create a virtual telescope 9,650 km(6,000 miles) across. TANAMI is a long-term program monitoring 100 active galaxies that are located in the southern sky. Since TANAMI is watching other active galaxies, and the energetic jets coming from them, it was able to exclude them as the source for Big Bird.
The team behind this new paper, including lead author Matthias Kadler of the University of Wuerzberg in Germany, think they’ve found the source for Big Bird. They say, with only a 5 percent chance of being wrong, that PKS B1424-418 is indeed Big Bird’s source. As they say in their paper, “The outburst of PKS B1424–418 provides an energy output high enough to explain the observed petaelectronvolt event (Big Bird), suggestive of a direct physical association.”
So what does this mean? It means that we can pinpoint the source of a neutrino. And that’s good for science. Neutrinos are notoriously difficult to detect, and they’re not that well understood. The new detection method, involving the Fermi Telescope in conjunction with the TANAMI array, will not only be able to locate the source of super-energetic neutrinos, but now the detection of a neutrino by IceCube will generate a real-time alert when the source of the neutrino can be narrowed down to an area about the size of the full Moon.
This promises to open a whole new window on neutrinos, the plentiful yet elusive ‘ghost particles’ that populate the Universe.
The primary mirror of the James Webb Space Telescope, in all its gleaming glory! Image: NASA/Chris Gunn
The James Webb Space Telescope (JWST) isn’t even operational yet, and already its gleaming golden mirror has reached iconic status. It’s segmented mirror is reminiscent of an insect eye, and once that eye is unfolded at its eventual stationary location at L2, the JWST will give humanity its best view of the Universe yet. Now, NASA has unveiled the JWST’s mirrors in a clean room at the Goddard Space Flight Centre, giving us a great look at what the telescope will look like when it’s operational.
Even if you didn’t know anything about the JWST, its capabilities, or its torturous path to finally being built, you would still look at it and be impressed. It’s obviously a highly technological, highly engineered, one of a kind object. In fact, you could be forgiven for mistaking it for a piece of modern art. (I’ve seen less appealing modern art, have you?)
The fact that the JWST will outperform its predecessor, the Hubble, is a well-known fact. After all, the Hubble is pretty long in the tooth now. But how exactly it will outperform the Hubble, and what the JWST’s mission objectives are, is less well-known. It’s worth it to take a look at the objectives of the JWST, again, and re-visit the enthusiasm that has surrounded this mission since its inception.
The James Webb Space Telescope in the clean room at the Goddard Space Flight Center. Image: NASA/Chris Gunn
NASA groups JWST’s science objectives into four areas:
infrared vision that acts like a time-machine, giving us a look at the first stars and galaxies to form in the Universe, over 13 billion years ago.
a comparative study of the stately spiral and elliptical galaxies of our age with the faintest, earliest galaxies to form in the Universe.
a probing gaze through clouds of dust, to watch stars and planets being born.
a look at extrasolar planets, and their atmospheres, keeping an eye out for biomarkers.
That is an impressive list, even in an age where people take technological and scientific progress for granted. But alongside these noble objectives, there will no doubt be some surprises. Guessing what those surprises might be is a bit of a fool’s errand, but this is the internet, so let’s dare to be foolish.
We have an idea that abiogenesis on Earth happened fairly quickly, but we have nothing to compare it to. Will we learn enough about exoplanets and their atmospheres to shed some light on conditions needed for life to happen? It’s a stretch, but who knows?
We have an understanding of the expansion of the Universe, and it’s backed up by pretty solid evidence. Will we learn something surprising about this? Or something that sheds some light on Dark Matter and Dark Energy, and their role in the early Universe?
Or will there be surprising findings in the area of planetary and stellar formation? The capability to look deeply into dust clouds should certainly reveal things previously unseen, but only guessed at.
Of course, not everything needs to be surprising to be exciting. Evidence that supports and fine tunes current theories is also intriguing. And the James Webb should deliver a boatload of evidence.
There’s no question that the JWST will outdo the Hubble in the science department. But for a generation or two of people, the Hubble will always have a special place. It drew many of us in, with its breathtaking pictures of nebulae and other objects, its famous Deep Field study, and, of course, its science. It was probably the first telescope to gain celebrity status.
The James Webb will probably never gain the social status that the Hubble gained. It’s kind of like the Beatles, there can only be one ‘first of its kind.’ But the JWST will be much more powerful, and will reveal to us a lot that has been hidden.
The JWST will be a grand technological accomplishment, if all goes well and it makes it to L2 and is fully functional. Its ability to look deeply into dust clouds, and to look back in time, to the early days of the Universe, make it a potent scientific tool.
And if engineering can figure out a way to reverse the polarity in the warp core without it going crit, we should be able to fire a beam of tachyon anti-matter neutrinos and de-cloak a Romulan Warbird at a distance of 3 AUs. Not bad for something Congress threatened to cancel!
This annotated artist's conception illustrates our current understanding of the structure of the Milky Way galaxy. Image Credit: NASA
Astronomers have found a pair of stellar oddballs out in the edges of our galaxy. The stars in question are a binary pair, and the two companions are moving much faster than anything should be in that part of the galaxy. The discovery was reported in a paper on April 11, 2016, in the Astrophysical Journal Letters.
The binary system is called PB3877, and at 18,000 light years away from us, it’s not exactly in our neighborhood. It’s out past the Scutum-Centaurus Arm, past the Perseus Arm, and even the Outer Arm, in an area called the galactic halo. This binary star also has the high metallicity of younger stars, rather than the low metallicity of the older stars that populate the outer reaches. So PB3877 is a puzzle, that’s for sure.
PB3877 is what’s called a Hyper-Velocity Star (HVS), or rogue star, and though astronomers have found other HVS’s, more than 20 of them in fact, this is the first binary one found. The pair consists of a hot sub-dwarf primary star that’s over five times hotter than the Sun, and a cooler companion star that’s about 1,000 degrees cooler than the Sun.
Hyper-Velocity stars are fast, and can reach speeds of up to 1,198 km. per second, (2.7 million miles per hour,) maybe faster. At that speed, they could cross the distance from the Earth to the Moon in about 5 minutes. But what’s puzzling about this binary star is not just its speed, and its binary nature, but its location.
Hyper-Velocity stars themselves are rare, but PB3877 is even more rare for its location. Typically, hyper velocity stars need to be near enough to the massive black hole at the center of a galaxy to reach their incredible speeds. A star can be drawn toward the black hole, accelerated by the unrelenting pull of the hole, then sling-shotted on its way out of the galaxy. This is the same action that spacecraft can use when they gain a gravity assist by travelling close to a planet.
This video shows how stars can accelerate when their orbit takes them close to the super-massive black holes at the center of the Milky Way.
But the trajectory of PB3877 shows astronomers that it could not have originated near the center of the galaxy. And if it had been ejected by a close encounter with the black hole, how could it have survived with its binary nature intact? Surely the massive pull of the black hole would have destroyed the binary relationship between the two stars in PB3877. Something else has accelerated it to such a high speed, and astronomers want to know what, exactly, did that, and how it kept its binary nature.
Barring a close encounter with the super-massive black hole at the center of the Milky Way, there are a couple other ways that PB3877 could have been accelerated to such a high velocity.
One such way is a stellar interaction or collision. If two stars were travelling at the right vectors, a collision between them could impart energy to one of them and propel it to hyper-velocity. Think of two pool balls on a pool table.
Another possibility is a supernova explosion. It’s possible for one of the stars in a binary pair to go supernova, and eject it’s companion at hyper-velocity speeds. But in these cases, either stellar collision or supernova, things would have to work out just right. And neither possibility explains how a wide-binary system like this could stay intact.
Fraser Cain sheds more light on Hyper-Velocity Stars, or Rogue Stars, in this video.
There is another possibility, and it involves Dark Matter. Dark Matter seems to lurk on the edge of any discussion around something unexplained, and this is a case in point. The researchers think that there could be a massive cocoon or halo of Dark Matter around the binary pair, which is keeping their binary relationship intact.
As for where the binary star PB3788 came from, as they say in the conclusion of their paper, “We conclude that the binary either formed in the halo or was accreted from the tidal debris of a dwarf galaxy by the Milky Way.” And though the source of this star’s formation is an intriguing question, and researchers plan follow up study to verify the supernova ejection possibility, its possible relationship with Dark Matter is also intriguing.
Young stars have a disk of gas and dust around them called a protoplanetary disk. Credit: NASA/JPL-Caltech
It might seem incongruous to find water ice in the disk of gas and dust surrounding a star. Fire and ice just don’t mix. We would never find ice near our Sun.
But our Sun is old. About 5 billion years old, with about 5 billion more to go. Some younger stars, of a type called Herbig Ae/Be stars (after American astronomer George Herbig,) are so young that they are surrounded by a circumstellar disk of gas and dust which hasn’t been used up by the formation of planets yet. For these types of stars, the presence of water ice is not necessarily unexpected.
Water ice plays an important role in a young solar system. Astronomers think that water ice helps large, gaseous, planets to form. The presence of ice makes the outer section of a planetary disk more dense. This increased density allows the cores of gas planets to coalesce and form.
Young solar systems have what is called a snowline. It is the boundary between terrestrial and gaseous planets. Beyond this snowline, ice in the protoplanetary disk encourages gas planets to form. Inside this snowline, the lack of water ice contributes to the formation of terrestrial planets. You can see this in our own Solar System, where the snowline must have been between Mars and Jupiter.
A team of astronomers using the Gemini telescope observed the presence of water ice in the protoplanetary disk surrounding the star HD 100546, a Herbig Ae/Be star about 320 light years from us. At only 10 million years old, this star is rather young, and it is a well-studied star. The Hubble has found complex, spiral patterns in the disk, and so far these patterns are unexplained.
HD 100546 is also notable because in 2013, research showed the probable ongoing formation of a planet in its disk. This presented a rare opportunity to study the early stages of planet formation. Finding ice in the disk, and discovering how deep it exists in the disk, is a key piece of information in understanding planet formation in young solar systems.
Finding this ice took some clever astro-sleuthing. The Gemini telescope was used, with its Near-Infrared Coronagraphic Imager (NICI), a tool used to study gas giants. The team installed H2O ice filters to help zero in on the presence of water ice. The protoplanetary disk around young stars, as in the case of HD 100546, is a mixed up combination of dusts and gases, and isolating types of materials in the disk is not easy.
Water ice has been found in disks around other Herbig Ae/Be stars, but the depth of distribution of that ice has not been easy to understand. This paper shows that the ice is present in the disk, but only shallowly, with UV photo desorption processes responsible for destroying water ice grains closer to the star.
It may seem trite so say that more study is needed, as the authors of the study say. But really, in science, isn’t more study always needed? Will we ever reach the end of understanding? Certainly not. And certainly not when it comes to the formation of planets, which is a pretty important thing to understand.
A team of astronomers from South Africa have noticed a series of supermassive black holes in distant galaxies that are all spinning in the same direction. Credit: NASA/JPL-Caltech
Astronomers have found a massive black hole in a place they never expected to find one. The hole comes in at 17 billion solar masses, which makes it the second largest ever found. (The largest is 21 billion solar masses.) And though its enormous mass is noteworthy, its location is even more intriguing.
Supermassive black holes are typically found at the centers of huge galaxies. Most galaxies have them, including our own Milky Way galaxy, where a comparatively puny 4 million solar mass black hole is located. Not only that, these gargantuan holes tend to be located in galaxies that are part of a large cluster of galaxies. Being surrounded by all that mass is a prerequisite for the formation of supermassive black holes. The largest one known, at 21 billion solar masses, is located in a very dense region of space called the Coma Cluster, where over 1,000 galaxies have been identified.
The largest supermassive holes also tend to be surrounded by bright companions, who have also grown large from the plentiful mass in their surroundings. (Of course, its not the black holes that are bright, but the quasars that surround them.) The long and the short of it is that supermassive black holes are usually found in galaxy clusters, and usually have other supermassive companions in the same region of space. They’re not found in isolation.
But this newly found black hole is in a rather sparse region of space. It’s in NGC 1600, an elliptical galaxy in the constellation Eridanus, 200 million light years from Earth. NGC 1600 is not a particularly large galaxy, and though it has been considered part of a larger group of galaxies, all its companions are much dimmer in comparison. So NGC 1600 is a rather small, isolated galaxy, with only a few dim companions.
A supermassive black hole of 17 billion solar masses has been found in the elliptical galaxy NGC 1600, a rather isolated galaxy with only dim companions. To date, supermassive black holes have only been found in huge galaxies at the centre of large clusters of galaxies. This image is a composite image from the Hubble and from ground observatories. Image Credit: NASA/ESA/Digital Sky Survey 2.
There’s another way that supermassive holes can form. Instead of growing large over time, by feeding on the mass of their home galaxies and galaxy clusters, they can form when two galaxies merge, and two smaller holes become one. But even this requires that they be in a region where galaxies are plentiful, allowing for more collisions and mergers.
It may be possible that NGC is the result of a merger of two galaxies, or that it is two black holes that are currently merging. Or it could be that NGC 1600’s region of space was once extremely rich in gas, in the early days of the Universe, and that’s what gave rise to this ‘out of place’ supermassive black hole.
There is much to be learned about the conditions that give rise to these behemoth black holes. The MASSIVE study will combine several telescopes to survey and catalogue the largest galaxies and black holes. This should tell astronomers a lot about their distribution, and about the circumstances that allow them to exist. We might find even larger ones.
In this March 2002 image, John Grunsfeld, former astronaut and associate administrator of NASA's Science Mission Directorate, is shown in space shuttle Columbia's cargo bay during the STS-109 Hubble servicing mission. Credits: NASA
In this March 2002 image, John Grunsfeld, former astronaut and associate administrator of NASA’s Science Mission Directorate, is shown in space shuttle Columbia’s cargo bay during the STS-109 Hubble servicing mission. Credits: NASA
Five time space shuttle astronaut and current NASA science chief John Grunsfeld – best known as the ‘Hubble Hugger’ for three critical and dramatic servicing and upgrade missions to the iconic Hubble Space Telescope – his decided to retire from the space agency he faithfully served since being selected as an astronaut in 1992.
“John Grunsfeld will retire from NASA April 30, capping nearly four decades of science and exploration with the agency. His tenure includes serving as astronaut, chief scientist, and head of NASA’s Earth and space science activities,” NASA announced.
Indeed, Grunsfeld was the last human to touch the telescope during the STS-125 servicing mission in 2009 when he served as lead spacewalker.
The STS-125 mission successfully upgraded the observatory to the apex of its scientific capability during five spacewalks by four astronauts and extended the life of the aging telescope for many years. Hubble remains fully operable to this day!
In April 2015, Hubble celebrated 25 years of operations, vastly outperforming its planned lifetime of 15 years.
“Hubble has given us 25 years of great service. Hopefully we’ll get another 5 to 10 years of unraveling the mysteries of the Universe,” Grunsfeld told me during a recent interview at NASA Goddard.
Astronaut John Grunsfeld performs work on the Hubble Space Telescope on the first of five STS-125 spacewalks. Credit: NASA
In his most recent assignment, Grunsfeld was NASA’s Science Chief working as the Associate Administrator for the Science Mission Directorate (SMD) at NASA Headquarters in Washington, D.C. since January 2012.
“John leaves an extraordinary legacy of success that will forever remain a part of our nation’s historic science and exploration achievements,” said NASA Administrator Charlie Bolden, in a statement.
“Widely known as the ‘Hubble Repairman,’ it was an honor to serve with him in the astronaut corps and watch him lead NASA’s science portfolio during a time of remarkable discovery. These are discoveries that have rewritten science textbooks and inspired the next generation of space explorers.”
Grunsfeld was inducted into the U.S. Astronaut Hall of Fame in 2015.
He received his PhD in physics in 1988 and conducted extensive research as an astronomer in the fields of x-ray and gamma ray astronomy and high-energy cosmic ray studies.
Crew of STS-125, including John Grunsfeld, center, during walkout to Astrovan ahead of launch on May 11, 2009, from the Kennedy Space Center in Florida on final mission to service NASA’s Hubble Space Telescope. Credit: Ken Kremer – kenkremer.com
NASA said that Grunsfeld’s deputy Geoff Yoder will serve as SMD acting associate administrator until a successor is named.
“After exploring strange new worlds and seeking out new life in the universe, I can now boldly go where I’ve rarely gone before – home,” said Grunsfeld.
“I’m grateful to have had this extraordinary opportunity to lead NASA science, and know that the agency is well-positioned to make the next giant leaps in exploration and discovery.”
During his tenure as science chief leading NASA’s Science Mission Directorate Grunsfeld was responsible for managing over 100 NASA science missions including the Mars orbital and surface assets like the Curiosity and Opportunity Mars rovers, New Horizons at Pluto, MESSENGER, upcoming Mars 2020 rover and OSIRIS-Rex as well as Earth science missions like the Deep Space Climate Observatory, Orbiting Carbon Observatory-2, and Global Precipitation Measurement spacecraft -which resulted numerous groundbreaking science, findings and discoveries.
NASA Associate Administrator for the Science Mission Directorate John Grunsfeld, left, New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO, second from left, New Horizons Mission Operations Manager Alice Bowman of the Johns Hopkins University Applied Physics Laboratory (APL), second from right, and New Horizons Project Manager Glen Fountain of APL, right, are seen at the conclusion of a press conference after the team received confirmation from the spacecraft that it has completed the flyby of Pluto, Tuesday, July 14, 2015 at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. Credit: Ken Kremer/kenkremer.com
Dr. Grunsfeld is a veteran of five spaceflights: STS-67 (1995), STS-81 (1997), STS-103 (1999) STS-109 (2002) and STS-125 (2009), during which time he logged more than 58 days in space, including 58 hours and 30 minutes of EVA in 8 spacewalks.
He briefly retired from NASA in December 2009 to serve as Deputy Director of the Space Telescope Science Institute, in Baltimore, Maryland. He then returned to NASA in January 2012 to serve as SMD head for over four years until now.
NASA Science chief and astronaut John Grunsfeld discusses James Webb Space Telescope project at NASA Goddard Space Flight Center in Maryland. Credit: Ken Kremer/kenkremer.com
From his NASA bio, here is a summary of John Grunsfeld’s space flight experience during five shuttle flights:
STS-67/Astro-2 Endeavour (March 2 to March 18, 1995) launched from Kennedy Space Center, Florida, and landed at Edwards Air Force Base, California. It was the second flight of the Astro observatory, a unique complement of three ultraviolet telescopes. During this record-setting 16-day mission, the crew conducted observations around the clock to study the far ultraviolet spectra of faint astronomical objects and the polarization of ultraviolet light coming from hot stars and distant galaxies. Mission duration was 399 hours and 9 minutes.
STS-81 Atlantis (January 12 to January 22, 1997) was a 10-day mission, the fifth to dock with Russia’s Space Station Mir and the second to exchange U.S. astronauts. The mission also carried the Spacehab double module, providing additional middeck locker space for secondary experiments. In 5 days of docked operations, more than 3 tons of food, water, experiment equipment and samples were moved back and forth between the two spacecraft. Grunsfeld served as the flight engineer on this flight. Following 160 orbits of the Earth, the STS-81 mission concluded with a landing on Kennedy Space Center’s Runway 33, ending a 3.9-million-mile journey. Mission duration was 244 hours and 56 minutes.
STS-103 Discovery (December 19 to December 27, 1999) was an 8-day mission, during which the crew successfully installed new gyroscopes and scientific instruments and upgraded systems on the Hubble Space Telescope (HST). Enhancing HST scientific capabilities required three spacewalks (EVAs). Grunsfeld performed two spacewalks, totaling 16 hours and 23 minutes. The STS-103 mission was accomplished in 120 Earth orbits, traveling 3.2 million miles in 191 hours and 11 minutes.
STS-109 Columbia (March 1 to March 12, 2002) was the fourth HST servicing mission. The crew of STS-109 successfully upgraded the HST, installing a new digital camera, a cooling system for the infrared camera, new solar arrays and a new power system. HST servicing and upgrades were accomplished by four crewmembers during a total of five EVAs in 5 consecutive days. As Payload Commander on STS-109, Grunsfeld was in charge of the spacewalking activities and the Hubble payload. He also performed three spacewalks totaling 21 hours and 9 minutes, including the installation of the new Power Control Unit. STS-109 orbited the Earth 165 times and covered 3.9 million miles in over 262 hours.
STS-125 Atlantis (May 11 to May 24, 2009) was the fifth and final Hubble servicing mission. After 19 years in orbit, the telescope received a major renovation that included the installation of a new wide-field camera, a new ultraviolet telescope, new batteries, a guidance sensor, gyroscopes and other repairs. Grunsfeld served as the lead spacewalker in charge of the spacewalking and Hubble activities. He performed three of the five spacewalks on this flight, totaling 20 hours and 58 minutes. For the first time while in orbit, two scientific instruments were surgically repaired in the telescope. The STS-125 mission was accomplished in 12 days, 21 hours, 37 minutes and 09 seconds, traveling 5,276,000 miles in 197 Earth orbits.
Launch of Space Shuttle Atlantis on STS-125 and the final servicing mission to the Hubble Space Telescope on May 11, 2009 from Launch Complex-39A at the Kennedy Space Center in Florida. Credit: Ken Kremer – kenkremer.com
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Learn more about Hubble, NASA Mars rovers, Orion, SLS, ISS, Orbital ATK, ULA, SpaceX, Boeing, Space Taxis, NASA missions and more at Ken’s upcoming outreach events:
Apr 9/10: “NASA and the Road to Mars Human Spaceflight programs” and “Curiosity explores Mars” at NEAF (NorthEast Astronomy and Space Forum), 9 AM to 5 PM, Suffern, NY, Rockland Community College and Rockland Astronomy Club – http://rocklandastronomy.com/neaf.html
Apr 12: Hosting Dr. Jim Green, NASA, Director Planetary Science, for a Planetary sciences talk about “Ceres, Pluto and Planet X” at Princeton University; 7:30 PM, Amateur Astronomers Assoc of Princeton, Peyton Hall, Princeton, NJ – http://www.princetonastronomy.org/
Apr 17: “NASA and the Road to Mars Human Spaceflight programs”- 1:30 PM at Washington Crossing State Park, Nature Center, Titusville, NJ – http://www.state.nj.us/dep/parksandforests/parks/washcros.html
NASA Administrator Charles Bolden and science chief Astronaut John Grunsfeld discuss NASA’s human spaceflight initiatives backdropped by the service module for the Orion crew capsule being assembled at the Kennedy Space Center. Credit: Ken Kremer/kenkremer.com
Andromeda's spinning neutron star. Though astronomers think there are over 100 million of these objects in the Milky Way, this is the first one found in Andromeda. Image: ESA/XMM Newton.
On a clear night, away from the bright lights of a city, you can see the smudge of the Andromeda galaxy with the naked eye. With a backyard telescope, you can take a good look at the Milky Way’s sister galaxy. With powerful observatories, it’s possible to see deep inside Andromeda, which is what astronomers have been doing for decades.
Now, astronomers combing through data from the ESA’s XMM Newton space telescope have found something rare, at least for Andromeda; a spinning neutron star. Though these objects are common in the Milky Way, (astronomers think there are over 100 million of them) this is the first one discovered in Andromeda.
A neutron star is the remnant of a massive star that went supernova. They are the smallest and most dense stellar objects known. Neutron stars are made entirely of neutrons, and have no electrical charge. They spin rapidly, and can emit electromagnetic energy.
If the neutron star is oriented toward Earth in just the right way, we can detect their emitted energy as pulses. Think of them as lighthouses, with their beam sweeping across Earth. The pulses of energy were first detected in 1967, and given the name pulsar.” We actually discovered pulsars before we knew that neutron stars existed.
Many neutron stars, including this one, exist in binary systems, which makes them easier to detect. They cannibalize their companion star, drawing gas from the companion into their magnetic fields. As they do so, they emit high energy pulses of X-ray energy.
The star in question, which astronomers, with their characteristic flair for language, have named 3XMM J004301.4+413017, spins rapidly: once every 1.2 seconds. It’s neighbouring star orbits it once every 1.3 days. While these facts are known, a more detailed understanding of the star will have to wait for more analysis. But 3XMM J004301.4+413017 does appear to be an exotic object.
“It could be what we call a ‘peculiar low-mass X-ray binary pulsar’ – in which the companion star is less massive than our Sun – or alternatively an intermediate-mass binary system, with a companion of about two solar masses,” says Paolo Esposito of INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, Milan, Italy. “We need to acquire more observations of the pulsar and its companion to help determine which scenario is more likely.”
“We’re in a better position now to uncover more objects like this in Andromeda, both with XMM-Newton and with future missions such as ESA’s next-generation high-energy observatory, Athena,” added Norbert Schartel, ESA’s XMM-Newton project scientist.
This discovery is a result of EXTraS, a European Project that combs through XMM Newton data. “EXTraS discovery of an 1.2-s X-ray pulsar in M31” by P. Esposito et al, is published in the Monthly Notices of the Royal Astronomical Society, Volume 457, pp L5-L9, Issue 1 March 21, 2016.
An artist's conception of an extremely luminous infrared galaxy similar to the ones reported in this paper. Image credit: NASA/JPL-Caltech.
Astronomers might be running out of words when it comes to describing the brightness of objects in the Universe.
Luminous, Super-Luminous, Ultra-Luminous, Hyper-Luminous. Those words have been used to describe the brightest objects we’ve found in the cosmos. But now astronomers at the University of Massachusetts Amherst have found galaxies so bright that new adjectives are needed. Kevin Harrington, student and lead author of the study describing these galaxies, says, “We’ve taken to calling them ‘outrageously luminous’ among ourselves, because there is no scientific term to apply.”
The terms “ultra-luminous” and “hyper-luminous” have specific meanings in astronomy. An infrared galaxy is called “ultra-luminous” when it has a rating of about 1 trillion solar luminosities. At 10 trillion solar luminosities, the term “hyper-luminous” is used. For objects greater than that, at around 100 trillion solar luminosities, “we don’t even have a name,” says Harrington.
The size and brightness of these 8 galaxies is astonishing, and their existence comes as a surprise. Professor Min Yun, who leads the team, says, “The galaxies we found were not predicted by theory to exist; they’re too big and too bright, so no one really looked for them before.” These newly discovered galaxies are thought to be about 10 billion years old, meaning they were formed about 4 billion years after the Big Bang. Their discovery will help astronomers understand the early Universe better.
“Knowing that they really do exist and how much they have grown in the first 4 billion years since the Big Bang helps us estimate how much material was there for them to work with. Their existence teaches us about the process of collecting matter and of galaxy formation. They suggest that this process is more complex than many people thought,” said Yun.
Gravitational lensing plays a role in all this though. The galaxies are not as large as they appear from Earth. As their light passes by massive objects on its way to Earth, their light is magnified. This makes them look 10 times brighter than they really are. But event taking gravitational lensing into account, these are still impressive objects.
But it’s not just the brightness of these objects that are significant. Gravitational lensing of a galaxy by another galaxy is rare. Finding 8 of them is unheard of, and could be “another potentially important discovery,” says Yun. The paper highlights these galaxies as being among the most interesting objects for further study “because the magnifying property of lensing allows us to probe physical details of the intense star formation activities at sub-kpc scale…”
The team’s analysis also shows that the extreme brightness of these galaxies is caused solely by star formation.“The Milky Way produces a few solar masses of stars per year, and these objects look like they forming one star every hour,” Yun says. Harrington adds, “We still don’t know how many tens to hundreds of solar masses of gas can be converted into stars so efficiently in these objects, and studying these objects might help us to find out.”
It took a tag team of telescopes to discover and confirm these outrageously luminous galaxies. The team of astronomers, led by Professor Min Yun, used the 50 meter diameter Large Millimeter Telescope for this work. It sits atop an extinct volcano in Mexico, the 15,000 foot Sierra Negra. They also relied on the Herschel Observatory, and the Planck Surveyor.
The million-year-old star HL Tau and its protoplanetary disk. Image: Carrasco-Gonzalez et. al.; Bill Saxton, NRAO/AUI/NSF
The currently accepted theory of planet formation goes like this: clouds of gas and dust are compressed or begin to draw together. When enough material clumps together, a star is formed and begins fusion. As the star, and its cloud of gas and dust rotate, other clumps of matter coagulate within the cloud, eventually forming planets. Voila, solar system.
There’s lots of evidence to support this, but getting a good look at the early stages of planetary formation has been difficult.
But now, an international team of astronomers using the Karl G. Jansky Very Large Array (VLA) have captured the earliest image yet of the process of planetary formation. “We believe this clump of dust represents the earliest stage in the formation of protoplanets, and this is the first time we’ve seen that stage,” said Thomas Henning, of the Max Planck Institute for Astronomy (MPIA).
This story actually started back in 2014, when astronomers studied the star HL Tau and its dusty disk with the Atacama Large Millimetre/sub-millimetre Array (ALMA.) That image, which showed gaps in HL Tau’s proto-planetary disk caused by proto-planets sweeping up dust in their orbits, was at the time the earliest image we had of planet formation. HL Tau is only about a million years old, so planet formation in HL Tau’s system was in its early days.
Now, astronomers have studied the same star, and its disk, with the VLA. The capabilities of the VLA allowed them do get an even better look at HL Tau and its disk, in particular the denser area closest to the star. What VLA revealed was a distinct clump of dust in the innermost region of the disk that contains between 3 to 8 times the mass of the Earth. That’s enough to form a few terrestrial planets of the type that inhabit our inner Solar System.
On the left is the ALMA image of HL Tau. On the right is the VLA image showing the clump of dust near the star. Image: Carrasco-Gonzalez et al,; Bill Saxton, NRAO/AUI/NSF
“This is an important discovery, because we have not yet been able to observe most stages in the process of planet formation,” said Carlos Carrasco-Gonzalez from the Institute of Radio Astronomy and Astrophysics (IRyA) of the National Autonomous University of Mexico (UNAM).
Of course the star in question, HL Tau, is interesting as well. But the formation and evolution of stars is much more easily studied. It’s our theory of planet formation which needed some observational confirmation. “This is quite different from the case of star formation, where, in different objects, we have seen stars in different stages of their life cycle. With planets, we haven’t been so fortunate, so getting a look at this very early stage in planet formation is extremely valuable,” said Carrasco-Gonzalez.
