Download No. 53 - Institute for Astronomy

FOR AS
T
RO
NOMY
INSTITU
TE
i ‘i
U
ni
ve
wa
rsit
y of Ha
Nā Kilo Hōkū
The Ones Who Look to the Stars No. 53 • 2015
A Newsletter from the
Institute for Astronomy
University of Hawai‘i
www2.ifa.hawaii.edu/newsletters
Artist’s conception of the 30 Ari star
system. The system is composed of
four stars. The distant companion 30
Ari A is actually a pair of stars in a
close orbit. The research team discovered the fourth star in the system (the
left-most star in the image). That
star is a small red dwarf. A massive
planet orbits the star named 30 Ari
B in a nearly year-long orbit. Art by
Karen Teramura, UH IfA
One Planet, Four Stars
Contents
3. Mānoa Open House
4. Clues to atmospheres on
Earth-size exoplanets in the
habitable zone
5. Fastest known star in our
galaxy
6. UHNAI researcher finds new
microbes
7. HI STAR students at science
fairs
8. From the Director
Free Public Events
www.ifa.hawaii.edu/specialevents/
April 12, 11:00 a.m.–4:00 p.m.
UH IfA Mānoa Open House
Free admission and parking
May 2, 11:00 a.m. – 4:00 p.m.
Maunakea Outreach ‘Ohana
presents AstroDay at Hilo’s
Prince Kūhiō Plaza
Researchers, including IfA’s Christoph Baranec, who want to know
more about the influences of multiple stars on exoplanets have
found only the second known case of a planet in a four-star system.
Although the star system, 30 Ari, was previously known to scientists,
the new study increases the number of stars in it from three to four.
The system is located 136 light-years away in the constellation
Aries. Its gaseous planet is enormous, with 10 times the mass of Jupiter, and orbits its primary star every 335 days. The newly discovered
fourth star, whose distance from the planet is 23 times the Sun-Earth
distance, does not appear to have impacted the orbit of the planet.
The exact reason for this is uncertain, so the team is planning further
observations to better understand the orbit of the newly discovered
star and its complicated family dynamics.
Were it possible to see the skies from this world, the four stars
would look like one small sun and two very bright stars that would be
visible in daylight. If viewed with a large enough telescope, one would
see that one of those bright stars is actually a binary system—two
stars orbiting each other.
Please see 30 Ari, pg 2
Mars Once Had an Ocean and Perhaps Life
A primitive ocean on Mars held more water than Earth’s Arctic Ocean,
according to a NASA-sponsored study that IfA astronomer Alan
Tokunaga and graduate student Alain Khayat participated in. About
4.3 billion years ago, Mars would have had enough water to cover
its entire surface in a liquid layer about 450 feet (137 m) deep. More
likely, the water would have formed an ocean occupying almost half of
Mars’ northern hemisphere, in some regions reaching depths greater
than a mile (1.6 km). The wetter conditions mean that life was more
likely to have existed on Mars than previously thought.
This new estimate is based on detailed observations made at the
European Southern Observatory’s Very Large Telescope in Chile, and the
W.M. Keck Observatory and NASA Infrared Telescope Facility in Hawai‘i.
Tokunaga and Khayat gathered data with the two Hawai‘i telescopes.
The scientists used the ground-based observatories to measure
water signatures in the Red Planet’s atmosphere. They distinguished
the chemical signatures of two slightly different forms of water in
Mars’ atmosphere. One is the familiar H2O. The other is HDO, a naturally
occurring variation in which one hydrogen atom is replaced by a
heavier atom called deuterium. By comparing the ratio of HDO to
H2O in water on Mars today with the ratio in water trapped in a Mars
meteorite dating from about 4.5 billion years ago, scientists measured
the subsequent atmospheric changes and determined how much
water has escaped into space.
The team mapped H2O and HDO levels several times over nearly
six years, which is equal to approximately three Martian years. The
resulting data produced global snapshots of each compound, as well
as their ratio. These first-of-their-kind maps reveal regional variations
called microclimates and seasonal changes, even though modern Mars
is essentially a desert.
Please see Mars’ Ocean, pg 2
30 Ari Continued from pg 1
In recent years, dozens of planetary systems with two or
three host stars have been found, which isn’t too much of
a surprise, considering that binary stars are more common
in our galaxy than single stars such as our Sun. “About
four percent of solar-type stars are in quadruple systems,
which is up from previous estimates because observational techniques are steadily improving,” said Andrei
Tokovinin (Cerro Tololo Inter-American Observatory, Chile),
a co-author of the study.
Lead author Lewis Roberts (Jet Propulsion Laboratory)
and his colleagues want to understand the effects that
multiple stars can have on their developing youthful
planets. Evidence suggests that stellar companions can
influence the fate of planets by changing the planets’
orbits and even triggering some to grow more massive.
The “hot Jupiter” planets that whip around their stars in
just days, for example, might be gently nudged closer to
their primary star by the gravitational hand of a stellar
companion. “This result strengthens the connection
between multiple star systems and massive planets,” said
Roberts.
The discovery was made at Palomar Observatory using
two new adaptive optics technologies that compensate
for the blurring effects of Earth’s atmosphere: the robotic
Robo-AO adaptive optics system, developed under the
leadership of Baranec, and the PALM-3000 extreme
adaptive optics system, developed by a team at Caltech
and NASA’s Jet Propulsion Laboratory (JPL) that also
included Baranec.
targets,” said Baranec. “At the moment, Robo-AO is
the only instrument that can give us the necessary
combination of resolution and efficiency. Once we discover
something interesting with Robo-AO, we can follow up
with the ‘Formula 1’ systems, like PALM-3000 or the SCExAO system at the Subaru Telescope in Hawai‘i, to obtain
the absolute sharpest images possible. Additionally, we’re
planning to bring a new, more powerful Robo-AO system
to the University of Hawai‘i 2.2-m telescope to leverage
the pristine skies of Maunakea. We’ll use it for even
larger surveys and follow-up observations of asteroids
and supernovae discovered by ATLAS on Mauna Loa and
Haleakalā.”
“The discovery of this exciting system is only possible
when we quickly scan through large numbers of potential
For information about Robo-AO, www.ifa.hawaii.edu/Robo-AO/
For information about ATLAS, fallingstar.com
Mar’s Ocean Continued from pg 1
From the measurements of atmospheric water in the
near-polar region, the researchers determined the enrichment, or relative amounts of the two types of water, in
the planet’s permanent ice caps. The enrichment of the ice
caps told them how much water Mars must have lost—a
volume 6.5 times larger than the volume in the polar caps
now. That means the volume of Mars’ early ocean must
have been at least 5 million cubic miles (20 million cubic
kilometers).
Based on the surface of Mars today, a likely location for
this water would have been the Northern Plains, considered a good candidate because of the low-lying ground.
An ancient ocean there would have covered 19 percent of
the planet’s surface. By comparison, the Atlantic Ocean
occupies 17 percent of Earth’s surface.
A primitive ocean on Mars held more water than Earth’s
Arctic Ocean, but the Red Planet has lost 87 percent of
that water to space. Image Credit: NASA’s Goddard Space
Flight Center
A primitive ocean on Mars held more water than Earth’s
Arctic Ocean, but the Red Planet has lost 87 percent of
that water to space. Image by NASA’s Goddard Space Flight
Center.
2
Open House 2015
Join us for our annual Open House on Sunday, April 12,
from 11 a.m. to 4 p.m. at our Mānoa headquarters located
at 2680 Woodlawn Drive. The theme for this year is the International Year of Light proclaimed by the United Nations
General Assembly to raise awareness of the importance
of light and light-based technologies for sustainable
development.
Light-related activities will include observing the
Sun through telescopes, astrophotography, an infrared
camera that will allow you to see what you look like at
infrared wavelengths, a talk about the invisible (to our
eyes) Universe, and a spectroscopy school where you will
learn about the different kinds of light, such as infrared or
ultraviolet, and what they can tell us about distant bodies.
You will be able to experience air-powered rockets
brought by UH Mānoa SUPER-M (as in mathematics),
hands-on physics toys brought by the staff of the
Windward Community College Imaginarium, a 3-D printer
demonstration, and a wind tunnel courtesy of the Pacific
Aviation Museum.
The Bishop Museum is bringing its brand new Digitalis
portable planetarium so you can explore the night sky,
and the Polynesian Voyaging Society will be there, too.
The CAVE, a 3-D virtual environment, will again be
available for tours, and as usual you will be able to Ask
an Astronomer, who will be wearing a funny hat. For the
keiki, there will be face painting, sundial making, and
bottle-rocket launching.
There will be talks and videos on a variety of astronomy-related topics. Of special note is the talk by Brent
Tully, who will explain the Laniakea Supercluster, a vast
collection of over 100,000 galaxies whose Hawaiian name
honors the Polynesian navigators who used their knowledge of the heavens to cross the immense Pacific Ocean.
Admission and parking will be free. For the latest
information, see www.ifa.hawaii.edu/open-house/.
3
Three-Planet System Holds Clues to Atmospheres of Earth-size Worlds This whimsical cartoon shows the three newly discovered
Extrasolar planets are being discovered by the hundreds,
but are any of these newfound worlds really like Earth?
A planetary system recently discovered by the Kepler
spacecraft will help resolve this question.
The system of three planets, each just larger than
Earth, orbits a nearby star called EPIC 201367065. The
three planets are 1.5–2 times the size of Earth, and the
outermost planet orbits on the edge of the so-called
“habitable zone,” where the temperature may be just right
for liquid water, believed necessary to support life, on the
planet’s surface.
“We’ve learned in the past year that planets the size
and temperature of Earth are common in our Milky Way
galaxy,” explains IfA astronomer Andrew Howard. “We
also discovered some Earth-size planets that appear to
be made of the same materials as our Earth, mostly rock
and iron.”
The compositions of these newfound planets are
unknown. “There is a very real possibility that the outer
planet is rocky like Earth,” noted Erik Petigura, a University
of California, Berkeley graduate student who spent a year
visiting the IfA. “If so, this planet could have the right
temperature to support liquid water oceans.”
In addition to Howard and Petigura, IfA graduate
students Benjamin Fulton and Kimberly Aller, and IfA as-
tronomer Michael Liu are among the two dozen scientists
who contributed to the study. The planets were confirmed
by the NASA Infrared Telescope Facility (IRTF) and the
W.M. Keck Observatory in Hawai‘i, as well as telescopes in
California and Chile.
The new discovery paves the way for studies of the
atmosphere of a warm planet nearly the size of Earth. The
three new planets are particularly favorable for atmospheric studies because they orbit a nearby, bright star.
Next, the team of astronomers that made the discovery
hopes to observe the planets with the Hubble Space
Telescope and other observatories to determine what
elements are in the planets’ atmospheres. If Hubble finds
that these warm, nearly Earth-size planets have thick,
hydrogen-rich atmospheres, they will learn that there is
not much chance for life.
“A thin atmosphere made of nitrogen and oxygen
has allowed life to thrive on Earth. But nature is full of
surprises. Many extrasolar planets discovered by the
Kepler Mission are enveloped by thick, hydrogen-rich
atmospheres that are probably incompatible with life as
we know it,” says Ian Crossfield, the University of Arizona
astronomer who led this study.
The discovery is all the more remarkable because
Kepler is now hobbled by the loss of two reaction wheels
that kept it pointing at a fixed spot in space. Kepler,
extrasolar planets (right) casting shadows on their host
star that can been seen as eclipses, or transits, at Earth
(left). Earth can be detected by the same effect, but only
in the plane of Earth’s orbit (the ecliptic). During the K2
mission, many of the extrasolar planets discovered by the
Kepler telescope will have this lucky double cosmic alignment that would allow for mutual discovery—if there is
anyone on those planets to discover Earth. The three new
planets orbiting EPIC 201367065 are just out of alignment;
while they are visible from Earth, our solar system is tilted
just out of their view. Art by K. Teramura, UH IfA.
launched in 2009, was reborn in 2014 as “K2” with a
clever strategy of pointing the telescope in the plane of
the Earth’s orbit to stabilize the spacecraft. Kepler is back
to mining the cosmos for planets by searching for eclipses,
or transits, as planets orbit in front of their host stars and
periodically block some of the starlight.
Kepler sees only a small fraction of the planetary
systems in its gaze, those with orbital planes aligned
edge-on to our view from Earth. Planets with large orbital
tilts are simply missed by Kepler.
The planets orbiting EPIC 201367065 were not the first
discovered by the K2 mission. That distinction belongs to
HIP 116454b, which is two and a half times the size of
Earth. IfA astronomer Christoph Baranec supplied confirming data for this discovery with his Robo-AO instrument
mounted on the Palomar 1.5-meter telescope.
4
Fastest Star in Our Galaxy Propelled by a Thermonuclear Supernova
A team of astronomers, including IfA astronomer Eugene
Magnier, used the 10-meter Keck II and Pan-STARRS1
telescopes in Hawai‘i to find a star that breaks the galactic
speed record. It travels at about 1,200 kilometers per
second (about 2.7 million mph), a speed that will enable
the star to escape from our Milky Way galaxy.
“At that speed, you could travel from Earth to the
moon in 5 minutes,” Magnier commented.
The team showed that unlike the half-dozen other
known escaping stars, this compact star was ejected from
an extremely tight binary by a thermonuclear supernova
explosion.
Stars like the Sun are bound to our galaxy by its gravity
and orbit its center at relatively moderate velocities, tens
to a few hundreds of kilometers per second. Only a few
so-called hypervelocity stars are known that travel so
fast that they are unbound. A close encounter with the
supermassive black hole at the center of the Milky Way
is usually considered the most plausible mechanism for
enabling these stars to escape from the galaxy.
Stephan Geier (European Southern Observatory, Garching, Germany) led the team that observed the known
high-velocity star, US 708, with the Keck II telescope
to measure its distance and radial velocity component,
that is, how fast it is moving away from us. By carefully
combining position measurements from digital archives
with newer positions measured from images taken during
the Pan-STARRS1 survey, they were also able to derive the
tangential component of the star’s velocity, or how fast it
is moving perpendicular to us.
“By observing the sky repeatedly over several years, the
Pan-STARRS1 survey let us make a movie of the motions
of the stars in the sky. That enables us to study the
behaviors of extremely rare and weird stars like US708,”
Magnier explained.
By putting all the measurements together, they determined the total velocity of the star is 1,200 kilometers
per second, much higher than the velocities of the other
known stars in our galaxy. More importantly, the trajectory of US 708 allows them to rule out the Galactic Center,
and therefore, its supermassive black hole, as the possible
cause of US 708’s extreme velocity.
US 708 has additional peculiar properties that are in
marked contrast to other hypervelocity stars: it is a rapidly
rotating, compact helium star that probably formed as a
result of interaction with a close companion. Helium stars
are the remnant of a formerly massive star that has lost its
hydrogen envelope.
Thus, US 708 could have originally been part of an
ultracompact binary system in which it transferred
helium to a massive white dwarf companion, ultimately
triggering a thermonuclear explosion known as a type
Ia supernova. As a result of this explosion, the surviving
companion, US 708, was violently ejected from the
disrupted binary, and is now traveling at an extremely
high velocity.
These results provide observational evidence that
there is a link between helium stars and thermonuclear
supernovae, and are a step toward understanding the
progenitor systems of these mysterious explosions.
Artist’s conception of a star (left) being ejected from a
galaxy by a supernova explosion. In reality, the supernova
would have been faded away long before the star reached
that position. Art courtesy of ESA/Hubble, NASA.
5
Astrobiology Researcher Finds New Microbes
Two miles below the surface of the ocean, researchers
have discovered new microbes that “breathe” sulfate. The
microbes, which have yet to be classified and named, exist
in massive undersea aquifers—networks of channels in
porous rock beneath the ocean where water continually
churns. About one-third of Earth’s biomass is thought to
exist in this largely uncharted environment.
“It was surprising to find new bugs, but when we go to
warmer, relatively old and isolated fluids, we find a unique
microbial community,” said Alberto Robador, the lead
author of the paper on the findings who began the project
while he was a UH NASA Astrobiology Institute (NAI)
postdoctoral fellow.
“Finding diverse microbial life here on Earth helps
us understand what kinds of life may exist elsewhere in
our solar system and on planets orbiting other stars,” explained IfA astronomer Karen Meech, the head of UH NAI.
Sulfate is a compound of sulfur and oxygen that occurs
naturally in seawater. It is used commercially in everything
from car batteries to bath salts and can be aerosolized by
the burning of fossil fuels, increasing the acidity of the
atmosphere.
This graphic shows the innovative technology that allowed the scientists to collect samples of water from an aquifer two
miles below the ocean without contaminating the samples with ocean water. Credit: Courtesy of USC
Microbes that breathe sulfate—that is, gain energy
by reacting sulfate with organic (carbon-containing)
compounds—are thought to be some of the oldest types
of organisms on Earth. Other species of sulfate-breathing
microbes can be found in marshes and hydrothermal
vents.
Researchers from UH and the University of Southern
California took their samples from the Juan de Fuca Ridge
(off the coast of Washington state), where previous teams
had placed underwater laboratories, drilled into the ocean
floor. To place the labs, they lowered a drill through two
miles of ocean and bored through several hundred feet of
ocean sediment and into the rock where the aquifer flows.
Like the microbes on the forest floor that break down
leaf litter and dead organisms, the microbes in the ocean
also break down organic (carbon-based) material such as
dead fish and algae. Unlike their counterparts, however,
the microbes beneath the ocean crust often lack the oxygen that is used on land to effect the necessary chemical
reaction.
Instead, these microbes can use sulfate to break down
carbon from decaying biological material that sinks to the
sea bottom and makes its way into the crustal aquifer,
producing carbon dioxide.
Learning how these new microbes function will be
important to getting a more accurate, quantified understanding of the overall global carbon cycle—a natural
cycling of carbon through the environment in which it is
consumed by plants, exhaled by animals and enters the
ocean via the atmosphere. This cycle is currently being
disrupted by man-made carbon dioxide emissions.
“This is the first direct account of microbial activity in
these type of environments, and shows the potential of
these organisms to respire organic carbon,” said Robador,
who is now a postdoctoral research associate at USC’s
Center for Dark Energy Biosphere Investigations (C-DEBI).
HI STAR Students Succeed at Maui, State Science Fairs
For the third consecutive year students who have participated in IfA’s HI STAR program took top honors at the Maui
County Science and Engineering Fair. HI STAR, or Hawai‘i
Student/Teacher Astronomy Research, is an IfA program
that encourages middle and high school students to excel
in the sciences by teaching them how to do astronomical
research.
Sarah Jenkins and Lily Jenkins (Moloka‘i High School)
won the first place award for a project that studied
mangroves. Luke Jones (Kihei Charter School) won a
merit award, an award for mathematics, and an award for
“most technical and complete” for his project on modified
Newtonian dynamics that used data from the Las Cumbres
Observatory Global Telescope (LCOGT) network and the
Pan-STARRS telescope on Maui. Both of these projects
advanced to the state level.
Celeste Jongeneelen (home schooled) also won a merit
award and advanced to the state level. Her project on
identifying Ae/Be stars in young open clusters is the first
high school project that used the FLOYDS spectrograph on
the LCOGT 2.0-meter telescope network.
Christopher Kim and M. Thomas Sturm, who won
third place for Physics and Astronomy at last year’s Intel
International Science and Engineering Fair (ISEF), took this
year’s project, which studied the differences in helioseismic results using different spectral lines, to the state level
competition.
So how did these students do at the state level?
Luke Jones won second place overall, first place for
physics and astronomy, and first place among Hawai’i
public schools. He will be attending ISEF in May. Celeste
Jongeneelen won third place for physics and astronomy,
the Hawaiian astronomical award, and an award from
NASA. Christopher Kim and Thomas Sturm won an award
from the American Public Works Association.
HI STAR participants and parents at the state
science fair. Back row from left to right: Tracy
Jones and her son Luke Jones, Lily Jenkins,
Celeste Jongeneelen and her mom, Esther
Pollock-Jongeneelen, Christopher Lindsay,
Kayla Ishida, Christopher Kim, and M. Thomas
Sturm. Front Row: Sarah Jenkins and Hedi
Jenkins (mother of Sarah and Lily) with HI
STAR director Mary Kadooka. Photo courtesy
J. D. Armstrong.
In addition, HI STAR participants from O‘ahu, Lelani
Gamboa and Christopher Lindsay, also won awards at the
state fair, and Kayla Ishida came from Kaua‘i.
There were nine astronomy projects at the state fair.
J. D. Armstrong, IfA’s Maui Technology Education and
Outreach Specialist, mentored three of them (with IfA
alumnus Marco Micheli, in the case of Luke Jones), and
Katie Whitman (IfA alumna and current physics graduate
assistant), Larry Denneau (senior software engineer for
IfA’s ATLAS project), and Geoff Mathews (IfA alumnus and
current astronomy instructor) each mentored one.
Unfortunately, there will be no HI STAR program in
2015 because funding has lapsed. IfA staff who worked
on this very successful program hope to obtain funding so
that they can restart it in 2016.
7
From the Director
The JCMT handover signing. Back row: Jun Yan,
director, National Astronomical Observatories of
China; IfA Director Günther Hasinger; Gary Davis,
former director, Joint Astronomy Centre. Front row:
Paul Ho, director general, East Asian Observatory;
Matt Platz , assistant chancellor for academic
affairs, UH; John Womersley, chief executive STFC.
Credit: Hollyn Johnson/Gary Davis/STFC.
Nā Kilo Hōkū
“The Ones Who Look to the Stars”
No. 53 • 2015
Published by
The University of Hawai‘i
Institute for Astronomy
www.ifa.hawaii.edu
Günther Hasinger IfA Director
Louise H. Good Editor
Karen Teramura Design/Production
Roy Gal Education & Outreach
TE
FOR AS
T
RO
NOMY
INSTITU
Nā Kilo Hōkū is also online:
www2.ifa.hawaii.edu/newsletters/
i ‘i
U
ni
ve
wa
rsit
y of Ha
On March 1, the University of Hawai‘i assumed ownership
of the James Clerk Maxwell Telescope (JCMT) located on
Maunakea. It was formerly owned by the Science and
Technologies Facilities Council (STFC) of the United Kingdom.
Simultaneously, the operation of JCMT was assumed by the
East Asian Observatory (EAO), a consortium of astronomy
agencies in China, Japan, South Korea, and Taiwan, under a
scientific cooperation agreement with UH. JCMT will continue
to be operated from the Joint Astronomy Centre Building
in Hilo by most of the same personnel. Dr. Paul Ho, former
director of Taiwan’s Academia Sinica Institute of Astronomy
and Astrophysics and now director general of EAO, now
heads the JCMT.
UH Institute for Astronomy
2680 Woodlawn Drive
Honolulu, HI 96822-1839
This new arrangement is similar to the one developed for
the United Kingdom Infrared Telescope (UKIRT). UH assumed
ownership of that telescope on October 31, 2014, and negotiated a scientific cooperation agreement with the University
of Arizona and Lockheed Martin Space Technology Advanced
Research and Development Laboratories to provide for UKIRT’s
continued scientific operation. Though both UKIRT and JCMT
have been very successful scientifically, STFC announced in
2012 that it no longer had the funds to support them.
UH will continue to receive a guaranteed share of the
observing time on both telescopes. We at IfA are glad that we
have been able to make arrangements to keep these valuable
telescopes operating.
Please join us for the annual IfA Mānoa Open House on
April 12.