FOR A E ST T R U O No. 35 • 2010 T I N

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Institute for Astronomy U ‘ i n i i a ve w Na¯ Kilo Ho¯ku¯ r a THE ONES WHO LOOK TO THE STARS University of Hawai‘i sity of H Imaging Other Worlds: NICI Planet-Finding Campaign by Michael C. Liu One of the most exciting developments in astronomy has been the discovery and characterization of —planets orbiting stars other than our Sun. Our understanding of these objects has advanced by leaps and bounds over the past 15 , since the discovery of the first around the Sun-like star 51 Pegasi in 1995. We now are entering a rich and special time for such studies. The current exoplanet census now exceeds 400 objects, most of them with comparable to the gas-giant planet Jupiter, which has a of one-thousandth that of the Sun, or 300 times that of Earth. Most exoplanets have been identified by the very subtle gravitational tug they exert on their host stars. While these discoveries have been groundbreaking, such planets are studied only indirectly. Other planets have been found as they across the face of their host stars, thereby diminishing the amount of light we detect from them. Such planets can be studied in great detail, but they orbit very close to their stars, making them unlike any Gemini NICI Planet-Finding Campaign planets in our solar system. NICI image of a young star near Earth with a candidate The next major advance is direct imaging, that is, low-mass companion. The bright star in the center of the taking actual digital images of planets around other image is heavily dimmed by a barely transparent stars. Directly detecting light from exoplanets opens What’s Inside circular mask. The companion is at the 4 o'clock the door to a host of new information about their position. It would be undetectable by ordinary imagers, properties (temperature, composition, etc.) and their Humboldt Awards pg 3 but is easily detected by NICI. formation. Direct detection is Please see NICI, pg 2

Ma¯noa Open House & Hilo AstroDay pg 4 Planet Detected in Habitable Zone of Nearby Star Galaxy Collisions Create by Louise Good Large Black Holes, Quasars Sun’s Constant Size pg 6 A team led by IfA astronomer Nader Haghighipour has one gets for Earth for the same kind of calculation. discovered a planet with about the same mass as However, if the planet’s atmosphere holds in heat When, How Did Earth in the habitable zone of a star 36 light-years sufficiently, then the surface temperature will Become Friendly to Life? from Earth. Its detection is important because it certainly be warmer than minus 42 degrees. “indicates that observational techniques are on the Upcoming Events pg 7 The planet (HIP 57050b) circles its central star (HIP right track for finding habitable low-mass rocky 57050) every 41 days. The star, which is classified as From the Director pg 8 planets similar to Earth,” according to Haghighipour. an M dwarf, has a radius approximately 0.4 times that A planet is considered to be in the habitable zone if of the Sun, and has a mass about one-third of the its temperature is just right for having liquid water. Sun’s. “Because HIP 57050b is a giant planet, it is The approximate surface temperature of the above- unlikely that it is habitable,” Haghighipour notes. mentioned newly discovered planet is about minus 42 In the quest for potentially habitable planets, the degrees F, which was calculated by considering the nearest stars are of special importance. We know their surface temperature of the star, the planet’s size, the precise distances, as well as their masses, sizes, and The University of Hawai‘i proportion of the star’s light that the planet may temperatures, and they are the only stars for which is an Equal Opportunity/ reflect, and the time that it spends in close proximity follow-up by Please see Planet Detected, pg 2 Affirmative Action Institution. to the star. This temperature is colder than the value for the blurring of astronomical images caused by NICI from pg 1 Earth’s turbulent atmosphere. incredibly challenging. We see the planets in our own Since December 2008, we have been using NICI to solar system because they reflect light from the Sun. obtain very sensitive images of 300 nearby young Imaging the reflected light of exoplanets is currently stars (within about 200 light-years) to search for impossible because the light reflected by the planets gas-giant planets in emitted light. The campaign will take about three years and obtain a total of 50 nights is swamped by the glare of their host stars, which are of observations. This makes it the largest single about a billion times brighter. However, when gas- program ever carried out at the Gemini telescopes. By giant planets are young, they also emit their own light having a major campaign, it is possible to assemble a at infrared wavelengths, by releasing the heat stored large-scale coherent science program with a unified in their interiors at the time of formation. This makes set of goals, observing methods, and data analysis young planets much easier to detect, since they are techniques. While the observations are carried out in only(!) about one million times fainter than their Chile, the planning and analysis are done here at the parent star. In 2008, astronomers took the first direct IfA, with postdoctoral fellow Zahed Wahhaj and images of young gas-giant exoplanets, thereby opening Hubble Fellow Beth Biller being key contributors. the door to this new way of learning about them. The campaign is about halfway finished. We have My research group is leading an international effort imaged about 180 stars so far, already making NICI known as the Gemini NICI Planet-Finding Campaign the largest direct imaging search to date. However, in to expand the census of exoplanets detected by direct some sense, we are just getting started. Many of the imaging. NICI (the Near-Infrared Coronagraphic stars we have imaged have very faint companions Imager) is a powerful new instrument installed on the next to them, but we do not yet know what these are. Gemini South 8.1-meter telescope in Chile, the twin They could be gas-giant planets in orbit around these stars, or they could be ordinary background stars that of the Gemini North telescope on Mauna Kea. Most are much farther away but by chance are projected on astronomical instruments can do multiple kinds of the sky nearby. The way to check is to make a second observations, but NICI was designed to do only one set of observations about one later to see if the thing very well, namely, image exoplanets directly. faint candidates move with the target star, thereby NICI was built by Doug Toomey of Mauna Kea proving that they are gravitationally bound together. Infrared in Hilo, with heavy involvement by IfA We are in the process of doing that right now. Once faculty members Christ Ftaclas and Mark Chun, and candidates are confirmed, we can learn a great deal funding from NASA. NICI is designed as a complete about the properties of young planets through end-to-end system for exoplanet imaging. It is based dedicated follow-up observations to measure their on an advanced adaptive optics system that corrects brightnesses, colors, atmospheres, and orbits.

Planet Detected from pg 1 and direct imaging is possible. While the majority of the currently known extrasolar planets have been detected around larger nearby stars, more than 70 percent of the nearest stars are M dwarfs. As such, these stars have the special properties (distances and masses) that drive exoplanetary science, astrobiol- ogy, and the next generation of interferometry and direct imaging missions. The low surface temperatures of M dwarfs place their habitable zones at distances that are approxi- mately 10 to 20 percent of Earth’s distance from the Sun. These distances correspond to orbital periods of 20–50 days, another advantage of M dwarfs as poten- tial targets for detecting habitable planets—because of their small masses, these stars respond more notice- ably to the gravitational forces of close-in planets. Haghighipour adds that it is interesting to specu- late about the possible presence of a moon around HIP 57050b. While it is not out of the question that HIP 57050b could harbor a moon, and that moon would thus be in the habitable zone of the parent star, an object with only one-fifth the mass of Mars is probably not a particularly good prospect for habitabil- ity from various standpoints. Furthermore, direct Orbit of the planet HIP 57050b superimposed on our solar system. The orbits are to scale, but the detection of such a moon would be extremely challenging. 2 size of the Sun and the planets are not. The star HIP 57050 is much smaller than our Sun. IfA Astronomers Win 2010 Humboldt Awards

Two IfA astronomers are the recipients of senior research awards from the Alexander von Humboldt Foundation in Germany. These research awards are intended to recognize the lifelong academic achievements of the awardees, are granted on the basis of nominations by eminent German scholars, and enable awardees to come to Germany to work on a research project with a German host. IfA Director Rolf-Peter Kudritzki, who will relin- quish the IfA directorship at the end of 2010, plans to use his Humboldt award during a 2011 sabbatical in Germany to investigate the physics of galaxies. Kudritzki will use the brightest stars in the Universe as tools to dissect galaxies. He will analyze spectra of hundreds of supergiant stars (stars with radii as large as 300 times the Sun and a hundred thousand times brighter) in distant galaxies. By applying completely new methods developed with his collaborators, who include IfA astronomers Fabio Bresolin and Miguel Urbaneja, Kudritzki will be able to use the spectra to determine the chemical compositions of galaxies and their distances from us. For instance, in spiral galaxies like our own Milky Way, the stars in the center have a higher percentage of elements heavier than hydrogen and helium than the Rolf-Peter Kudritzki (right) working with collaborator Fabio stars at the edges of the rotating spiral arms. Bresolin. They have worked together for more than 10 years. Data about the chemical composition of galaxies can be used to test the present theory about how to better than a few parts in a million (see article on galaxies have formed in an expanding Universe that is page 6). Kuhn said, “I plan to use this award to dominated by cold dark matter (matter that does not develop new models of how and why the solar cycle is interact with any form of light and whose constituent so dependent on the death cycle of sunspots.” He particles move more slowly than light) and dark added that the physics is not known but critical to energy (the mysterious force that is accelerating the understanding how all stars evolve and change, and expansion of the Universe). In fact, chemical analysis that “this understanding may ultimately help us is one of the very few ways to test this scenario quanti- predict how and when a changing Sun affects Earth's tatively. So far, the present knowledge of the chemical climate.” composition of spiral galaxies is very uncertain. IfA astronomer J. Patrick Henry spent the spring in Kudritzki’s new method will be the first to provide Germany on a Humboldt award that is a follow-up to Jeff Kuhn accurate numbers. the one he received in 2003. Henry is one of the “This project is entirely new. Nobody has ever world’s experts on the cosmological evolution of done anything like this, except Fabio, Miguel, and me. clusters of galaxies. He pioneered the use of X-ray Thus, I am truly excited and look forward to spending observations of clusters to understand how the entire all my energy and time on it. I will use all the largest Universe grows. His work provided some of the telescopes in the world for this project, including those earliest evidence for what has become the standard on Mauna Kea and in Chile, and also the Hubble Space description of that growth, including the idea that Telescope,” Kudritzki said. most matter in the Universe is dark matter. While in Germany, Henry finished a paper describing the Jeff Kuhn received his award on the strength of his properties of one of the most distant clusters of cumulative research studying the Sun. This is the first galaxies yet found. These very distant objects let time that a solar scientist from the United States has astronomers actually see how clusters of galaxies are been granted the prize. Kuhn’s research has often formed rather than deducing how they formed from focused on finding new ways to understand the solar studying the properties of fully grown examples. interior by using observations of its surface made by instruments on the ground and in space. His group IfA astronomer David Sanders is also a previous Pat Henry recently found that, unlike almost everything else that winner of a Humboldt research award. we measure about the Sun, it is constant in diameter 3 Making Comets Open House, Astroday Events

Hundreds of visitors attended the Ma¯ noa Open House, on April 18. Some came to see a fresnel lens melt a penny and fry an egg. Others came to hear the talks, such as Robert Jedicke explaining the connection between the origin of the Universe and the Large Hadron Collider. Children enjoyed making comets and sundials, seeing a show in the StarLab planetarium, packaging an egg so that it would survive a drop from the second floor (the Mars Drop), and launching a bottle rocket. While the weather cooperated, visitors viewed sunspots and Venus.

Lego Enthusiasts Association of Hawaii IfA Ma¯noa Open House

The Mars Drop Sunspot Observing

4 Magnetic Fields of the Sun AstroDay at Prince Ku¯hio¯ Plaza

Making Sundials

NASA IRTF demonstration with infrared camera

The ninth annual AstroDay Festival, which celebrates astronomy and Hawaiian culture, took place on May 1 at Prince Ku¯hio¯ Plaza in Hilo. More than 30 scientific and cultural booths provided attendees with the opportunity to play games, see planetarium shows and demonstrations, and win Celestron telescopes. As always, there was good entertainment, too. At the UH NAI Astrobiology beginning of the festivities, members of the Mauna Kea Observatories Outreach Committee honored AstroDay Ask an organizer (and IfA Science Education and Public Astronomer Outreach Officer) Gary Fujihara for his efforts to bring astronomy to the people.

Ma¯noa Open House photos by Karen Teramura.

The Fresnel Lens

“The Big Bang and Back Again” 5 talk by Robert Jedicke Merging galaxies

Artistic representation of the quasar stages after a major galaxy merger. Initially, the growing black hole is completely Obscured quasar enshrouded by large amounts of gas and dust. Unobscured quasar After about 100 million years, the strong pressure Merging galaxies: NASA, STScI/AURA, ESA Art by Karen Teramura provided by the quasar emission is enough to blow Galaxy Collisions Create Large Black Holes and Quasars out most of the surrounding Giant black holes at the centers of galaxies grow mainly distances, up 11 billion light-years away, seen as they gas, thus unveiling a as a result of intergalactic collisions, according to IfA were when the Universe was still in its infancy. “For “naked” quasar, which is astronomer Ezequiel Treister, leader of a study published many years, astronomers believed that these sources clearly detectable at optical in March. As gas clouds in galaxies are sucked into the were very rare. Now we are seeing them everywhere!” and ultraviolet wavelengths. central black hole, they emit vast amounts of radiation, Treister said. Because most of the emission from these giving rise to quasars, which are very luminous active obscured quasars is hidden, astronomers looked at galactic nuclei. “We find that these growing black holes infrared wavelengths for signs of very hot dust, and in are originally hidden by large amounts of dust, but after X-rays, which are less affected by obscuration. The 10–100 million years this dust is blown out by the strong investigators discovered that the number of obscured radiation pressure, leaving a naked quasar that is visible quasars relative to the unobscured ones was at optical wavelengths and keeps shining for another 100 significantly larger in the early Universe than it is now. million years,” Treister said. Other team members are Priyamvada Natarajan, For this study, Treister and his colleagues combined Meg Urry, and Kevin Schawinski (Yale), IfA astronomer data obtained with the Hubble, Chandra, and Spitzer David Sanders, and former IfA graduate student Jeyhan space observatories to identify a large number of Kartaltepe, who is now with the National Optical obscured, dust-enshrouded quasars at very large Astronomy Observatories in Arizona.

Sun’s Constant Size Surprises Scientists A group of astronomers led by the IfA’s Jeff Kuhn has found that in recent times the Sun’s size has been remarkably constant. Its diameter has changed by less than one part in a million over the last 12 years. “This constancy is baffling, given the violence of the changes we see every on the Sun’s surface and the fluctuations that take place over an 11-year solar cycle,” commented Kuhn, the IfA associate director who is responsible for Haleakala¯ Observatories. Kuhn’s work is part of worldwide efforts to understand the influence of the Sun on Earth’s climate. “We can’t predict the climate on Earth until we understand these changes on the Sun,” he said. Kuhn and his colleagues (Rock Bush from Stanford, Marcelo Emilio from Brazil, and Isabelle Scholl at IfA) used NASA’s long-lived Solar and Heliospheric Observatory (SOHO) satellite to monitor the Sun’s diameter, and they will soon repeat the experiment with much greater accuracy using NASA’s new Solar Dynamics Observatory (SDO), which was launched on February 11. According to Kuhn, the ultimate solution to this puzzle will depend on probing the smallest observable scales The Sun’s disk showing active region 10486, which of the solar surface using the Advanced Technology Solar Telescope (ATST), which is became the largest sunspot seen by SOHO, the scheduled for completion on Haleakala¯ in 2017. satellite Kuhn and collaborators used to monitor the Sun’s diameter. Courtesy of SOHO/MDI “To be able to predict what the Sun will do, we need both the big picture and the consortium. SOHO is a project of international details. Just as powerful hurricanes on Earth start as a gentle breeze, the analogs of terres- 6 cooperation between ESA and NASA. trial storms on the Sun start as small kinks in the Sun’s magnetic field,” said Kuhn. Upcoming Events

Please check with the sponsoring organization for specific times and locations for all events. O‘ahu Events: call (808) 956-8566 www.ifa.hawaii.edu/specialevents/ September (TBA), Frontiers of Astronomy Community Lecture.

Astrobiology Laboratory Institute for Art by Karen Teramura Instructors (ALI‘I) National Summer Teacher Workshop, June 27–July 2, When, How Did Earth Become Life Friendly? 2010. On March 31, a Frontiers of Astronomy Community Lecture presented by the IfA and the UH www.ifa.hawaii.edu/UHNAI/epo/alii.htm NASA Astrobiology Institute (NAI) attempted to answer the question, “When and how did our Friends of the IfA Events: planet become conducive to life?” Call (808) 956-6665 for more A panel consisting of Jeff Taylor, a geologist from the Hawai‘i Institute of Geophysics and information.

Planetology and a member of the UH NAI team; Karen Meech, IfA astronomer and principal www.ifa.hawaii.edu/friends/ investigator for UH NAI; and Steve Mojzsis from the Department of Geological Sciences at the Maui Events: call (808) 573-9516 University of Colorado explained what we know so far about this process. Steve Freeland, an Maui Maikalani Community Lectures evolutionary biologist who is now the project manager of UH NAI, served as moderator. usually occur on the second Friday of Freeland explained that NASA organized the NASA Astrobiology Institute (NAI) in 1998 to the month at the Maikalani Advanced study the origins, evolution, distribution, and future of life in the Universe and that UH NAI is Technology Research Center, 34 ‘O¯hia one of 14 NAI centers located throughout the United States. Life on Earth, he said, is amazingly Ku¯ Street, Pukalani, 6:30 p.m. Free. diverse, with only a small fraction of it visible to the unaided eye. Hawai‘i Island Events: So how did Earth, at first a ball of molten rock, evolve into a planet with a surface of blue (808) 932-2328 or [email protected] oceans and green lands filled with life? First, it was necessary to build a planet. Taylor spoke The AstroTalk lecture series is a monthly about what he termed the “haphazard” construction of our planet. In the solar nebula, dust grains free presentation at ‘Imiloa Astronomy collided and stuck together. Collisions led to larger and larger bodies. Less volatile elements and Center with the intent of bringing compounds, such as ferrous oxide (FeO), condensed out of the solar nebula at the higher together students, scientists, and temperatures prevalent in the inner solar system, so early Earth was mostly metallic and rocky. members of the community. For information, But what about water, which condenses at a much lower temperature? Liquid water is www.imiloahawaii.org required for life as we know it, so next Meech discussed the origin of Earth’s water. There is VISITING MAUNA KEA evidence of some water in many locations in the solar system—on Saturn’s moon Enceladus, on Mars, and on the Moon—but generally speaking, the inner planets are dry. Even on Earth, the The Onizuka Center for International Astronomy Visitor Information Station oceans account for only 0.023 percent of the planet’s mass, and the total amount of water is (VIS) at Hale Pohaku¯ (9,300-foot level of estimated at no more than a tenth of a percent of Earth’s mass. The exact amount of water on our Mauna Kea) is open daily, 9:00 a.m. to planet is undetermined, because scientists can only estimate how much water is deep beneath 10:00 p.m. Earth’s surface. "The Universe Tonight" features recent So where did Earth’s water come from? Was it captured from the solar nebula because water discoveries, 6:00 p.m., first Saturday of molecules stuck to the dust that eventually formed the planet? Did a major impact cause Earth’s every month. surface to melt into a magma ocean, after which hydrogen in the atmosphere reacted with oxygen "Malalo I Ka Lani Po¯," cultural aspects of to form water? Or did it arrive when asteroids or comets collided with Earth? Scientists are trying Mauna Kea, 6:00 p.m., third Saturday of to match the ratio of deuterium (D) to hydrogen (H) in the water from these sources with that on every month. Earth, but such attempts may not be accurate because we do not know the D/H ratio for water Public stargazing nightly from 6:00 to inside Earth. Meech concluded by saying Earth’s water probably came from many sources. 10:00 p.m. Summit tours begin at the Mojzsis spoke about how Earth became habitable, and how it is a laboratory in the search for VIS at 1:00 p.m. on Saturday and life elsewhere. Evidence shows that about 4.53 billion years ago (about 40 million years after the Sunday. For essential information, see solar system formed), a large body collided with the proto-Earth, causing the formation of the www.ifa.hawaii.edu/info/vis/summittour.html Moon and vaporizing magma on both bodies. After the collision, Earth cooled rapidly. Two million years later, it had an atmosphere of rock vapor and water vapor. Forty million to 600 FOR A million years after the solar system formed, Earth had water and a crust, and was ready for life. E ST T R U O We know this because geologists have found rocks that are 4.3 billion years old and include T I N

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It appears, then, that the answer to the question, “When and how did our planet become U ‘ i n i iv a conducive to life?” is “very early, and we still have much to learn.” er aw 7 sity of H www.ifa.hawaii.edu/UHNAI/

Dear Friends of the Institute for Astronomy,

Summer on a university campus is often a relatively quiet time, but so far, this summer has not been quiet at IfA Ma¯noa. While some of our faculty and staff are on out-of-town trips, they have more than been replaced by visitors from afar. First, undergraduates from throughout the United States (and one from France) arrived for the tenth annual Research Experiences for Undergraduate program. Each student will work with a faculty mentor on a research project throughout the summer. Eight of them are at IfA Ma¯noa, four are at IfA Hilo, and two are on Maui. On June 4, a group of Hawai‘i students entering grades 7–11 and their teachers came to Ma¯noa to participate in the Hawai‘i Student/Teacher Astronomy (HI STAR) program. Sponsored by the UH NASA Astrobiology Institute, with additional support from private donors, HI STAR is a weeklong “astronomy boot camp” for students and teachers who are passionate about astronomy and want to learn more about it.

Photo by Rainer Arlt/AIP, At this very hands-on workshop, they learned how to make observations, do image processing, and use Astronomischen Gesellschaft 2009, Potsdam software to measure the position and brightness of the observed objects. From June 7 to 10, 65 people attended the 2010 COSMOS Team Meeting here. COSMOS—the Cosmic Evolution Survey—has used the and other space- and ground-based observatories to survey a two-square-degree region of the sky in unprecedented detail. Team members came from 10 countries to share information and plan future research. Our solar scientists on Maui have also been busy. They hosted the Sixth Solar Polarization Workshop May 30 through June 4 at the Sheraton Maui Resort and Spa. One hundred scientists from throughout the world gathered to talk about using the technique called “polarimetry” to study the Sun and other stars. Have a safe and enjoyable summer. Aloha! Rolf-Peter Kudritzki Director, Institute for Astronomy

FOR A E ST T R U O T UH Institute for Astronomy I N

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Na¯ Kilo Ho¯ku¯ “The Ones Who Look to the Stars” No. 35 • 2010 Published by The University of Hawai‘i Institute for Astronomy

Rolf-Peter Kudritzki IfA Director

Louise H. Good Editor

Karen Teramura Design/Production

Education & Outreach Gary Fujihara, Island of Hawai‘i Mary Kadooka, O‘ahu, all islands J. D. Armstrong, Maui

2680 Woodlawn Drive Honolulu, Hawai‘i 96822 telephone (808) 956-8566

http://www.ifa.hawaii.edu/

Na¯ Kilo Ho¯ku¯ is also online: www2.ifa.hawaii.edu/newsletters/